Dactylogyrids ( Monogenoidea : Polyonchoinea ) parasitizing the gills of snappers ( Perciformes : Lutjanidae ) : Revision of Euryhaliotrema with new and previously described species from the Red Sea , Persian Gulf , the eastern and Indo-west Pacific Ocean , and the Gulf of Mexico

Twenty one of 29 species of snappers (Lutjanidae), examined for dactylogyrids (Monogenoidea) from the Red Sea, Persian Gulf, the Indo-west and eastern Pacific Ocean, the Gulf of Mexico, and Caribbean Sea were parasitized by 16 new and 11 previously described species of Euryhaliotrema: Euryhaliotrema adelpha sp. nov., Euryhaliotrema anecorhizion sp. nov., Euryhaliotrema cardinale sp. nov., Euryhaliotrema chrysotaeniae, Euryhaliotrema cognatus sp. nov., Euryhaliotrema cryptophallus sp. nov., Euryhaliotrema diplops sp. nov., Euryhaliotrema distinctum sp. nov., Euryhaliotrema fajeravilae sp. nov., Euryhaliotrema fastigatum, Euryhaliotrema fatuum sp. nov., Euryhaliotrema ferocis sp. nov., Euryhaliotrema hainanense, Euryhaliotrema longibaculum, Euryhaliotrema mehen comb. nov., Euryhaliotrema paracanthi, Euryhaliotrema paululum sp. nov., Euryhaliotrema perezponcei, Euryhaliotrema ramulum sp. nov., Euryhaliotrema seyi sp. nov., Euryhaliotrema simplicis sp. nov., Euryhaliotrema spirotubiforum, Euryhaliotrema tormocleithrum sp. nov., Euryhaliotrema torquecirrus, Euryhaliotrema tubocirrus, Euryhaliotrema xinyingense, and Euryhaliotrema youngi sp. nov. Six species of Euryhaliotrema, previously reported from lutjanid hosts, were not collected: Euryhaliotrema anguiformis comb. nov., Euryhaliotrema guangdongense, Euryhaliotrema johni, Euryhaliotrema lutiani, Euryhaliotrema lutjani, and Euryhaliotrema nanaoense comb. nov. The diagnosis of Euryhaliotrema was emended to include species having tandem or slightly overlapping gonads, a pretesticular germarium, a globose haptor with morphologically similar anchors and hooks, a coiled or meandering male copulatory organ, a dextral vaginal pore, and hooks with upright acute thumbs and slender shanks comprised of one subunit. A bulbous base of the MCO and presence of an accessory piece in the copulatory complex were no longer considered features defining the genus. As a result, Euryhaliotrematoides and Aliatrema were placed in subjective synonymy with Euryhaliotrema, and the following transfers were proposed: Euryhaliotrema annulocirrus comb. nov., Euryhaliotrema aspistis comb. nov., Euryhaliotrema berenguelae comb. nov., Euryhaliotrema cribbi comb. nov., Euryhaliotrema grandis comb. nov., Euryhaliotrema mehen comb. nov., Euryhaliotrema microphallus comb. nov., Euryhaliotrema pirulum comb. nov., and Euryhaliotrema triangulovagina comb. nov. In addition, the following new combinations were proposed based on the revised diagnosis of the genus: Euryhaliotrema anguiformis comb. nov., Euryhaliotrema eukurodai comb. nov., Euryhaliotrema kurodai comb. nov., Euryhaliotrema monoporosum comb. nov., and Euryhaliotrema nanaoense comb. nov. The dactylogyrids, Protancyrocephalus rangusi (from a lutjanid host) and Daitreosoma chaetodontis (from a chaetodontid host), were considered species inquirendae. Haliotrematoides tukerhamatus comb. nov. is considered the senior subjective synonym of Haliotrematoides nagabinae. New host records for some previously described species of Euryhaliotrema from lutjanid and chaetodontid hosts were reported.

ZOOLOGIA 29 (3): 227-276, June, 2012 Yang & Sun, 2009 with 24 species (12 new) infesting lutjanid hosts; two dactylogyrid species from caesionid hosts and four from sparid hosts were also included in Haliotrematoides by KRITSKY et al. (2009a).The present paper represents the second installment stemming from this investigation and includes a revision of Euryhaliotrema Kritsky & Boeger, 2002 and descriptions and reports of 27 new and previously described species from lutjanid hosts.

MATERIAL AND METHODS
The gills of twenty nine species of snappers (Lutjanidae) were examined for dactylogyrids: yellowbanded snapper, Lutjanus adettii (Castelnau) Snappers were collected by a variety of methods from marine waters off China, New Caledonia, Australia, the Maldive Islands, Egypt, Kuwait, Mexico, Nicaragua, Panama, and the USA by colleagues and friends (see Acknowledgments).Fish hosts were identified by the collectors using various resources available at the respective collection sites and facilities; scientific and common names of fishes are those provided in FishBase (FROESE &PAULY 2011) andverified in ESCHMEYER &FRICKE (2011).In most cases, the host's gill basket was removed soon after capture at the site of collection and placed in hot (60°C) 4% formalin to relax and fix the parasites.Fixed gills from each fish were pooled or placed individually in vials; vials containing the gills and respective fluids were labeled and shipped to Idaho State University for study.Dactylogyrids were subsequently removed from the gills or sediment using a small probe and dissecting microscope.Some specimens were mounted unstained in Gray and Wess medium (HUMASON 1979) or in ammonium picrate glycerine (MALMBERG 1970) for study of sclerotized structures; other specimens were stained with Gomori's trichrome or VanCleave's hematoxylin (KRITSKY et al. 1978, BULLARD et al. 2004) and mounted in Canada balsam for observing internal anatomy.Illustrations were prepared with the aid of a camera lucida or microprojector.Measurements, all in micrometers, represented straight-line distances between extreme points and were expressed as the mean followed by the range and number (n) of structures measured in parentheses; body length included that of the haptor; the measured dimension of the male copulatory organ (MCO) was that represented in the respective drawings as the distance between the parallel lines.Numbering of hook pairs followed that proposed by MIZELLE (1936) (see MIZELLE & PRICE 1963); direction of the coil (clockwise vs. counterclockwise) of the MCO was determined using the method suggested by KRITSKY et al. (1985).Descriptions of new species were based on specimens collected from the type locality and type host; all other specimens of the respective species were considered voucher specimens.Unless otherwise indicated, measurements of the new species are from specimens collected from the type host and type locality.Type and voucher specimens collected during the present study were deposited in the U.S. National Parasite Collection (USNPC), Beltsville, Maryland, the Florida Fish and Wildlife Conservation Commissions's Fish and Wildlife Research Institutes' Invertebrate Specimen Collection (FSBC-I), St. Petersburg, Florida, and the helminth collections of the Queensland Museum (QM), Brisbane, Australia; and the Muséum national d'Histoire naturelle (MNHN), Paris, France, as indicated in the respective species accounts.In addition, the following museum specimens were examined: paratype, Euryhaliotrema xinyingense Pan & Zhang, 2006[Natural History Museum, London, UK (NHMUK 2005.10.18.3-4)]; paratype, Euryhaliotrema hainanense Pan & Zhang, 2006(NHMUK 2005.10.18.1-2); 3 voucher specimens, Euryhaliotrema torquecirrus (Zhukov, 1976) Kritsky & Boeger, 2002 (USNPC 91432); 2 voucher specimens, Euryhaliotrema tubocirrus (Zhukov, 1976) Kritsky & Boeger, 2002 (USNPC 91431); and 4 paratypes, Euryhaliotrematoides mehen Soler-Jiménez, Garcia-Gasca & Fajer-Ávila, 2012 (USNPC 104737, 104738, 104739 & 104740).

TAXONOMY
Twenty one of 29 species of snappers (Lutjanidae), examined from the Red Sea, Persian Gulf, the Indo-west and eastern Pacific Ocean, the Gulf of Mexico and Caribbean Sea, were parasitized by 16 new and 11 previously described species of Euryhaliotrema (Tab.I).A specimen of an unidentified species of Euryhaliotrema (species 1, USNPC 105462) was also collected from a yellowbanded snapper, Lutjanus adettii, off Australia; and along with new and previously described species, two unidentified species of Euryhaliotrema (species 2 and 3, USNPC Remarks: Euryhaliotrema was proposed by KRITSKY & BOEGER (2002) for some new and previously described species of Dactylogyridae from snappers (Lutjanidae), drums and croakers (Sciaenidae), porgies (Sparidae) and grunts (Haemulidae).The genus was primarily characterized by dactylogyrids having a bulbous base of the MCO.PLAISANCE & KRITSKY (2004) subsequently proposed Euryhaliotrematoides Plaisance & Kritsky, 2004 and Aliatrema Plaisance & Kritsky, 2004 for similar species parasitizing butterflyfishes (Chaetodontidae) but having "funnel-shaped" bases of the MCO; species of Aliatrema also lack an accessory piece in the copulatory complex (accessory pieces present in species of Euryhaliotrema and Euryhaliotrematoides).However, some of the dactylogyrids collected from snappers during the present survey possessed a mix of these morphological features, suggesting that re-evaluation of the three genera was necessary.
Species currently assigned to Euryhaliotrema, Euryhaliotrematoides and Aliatrema share many morphological features, including tandem or slightly overlapping gonads, a pretesticular germarium, a globose haptor with morphologically similar anchors/bar complexes and hooks, a coiled or meandering MCO, a dextral vaginal pore, and hooks with an upright acute thumb and slender shank comprised of one subunit.However, the three genera can no longer be justified based solely on the morphology of the copulatory complex.In the species recovered from snappers, the aperture in the base of the MCO allowing entry of the spermatic and prostatic ducts, varies from inconspicuous in some species with bulbous bases to comparatively large in those with funnel-shaped bases (compare the MCOs of E. chrysotaeniae, Fig. 108 and E. distinctum, Fig. 120), while in some species (i.e., E. anecorhizion, Fig. 59) with bulbous bases, the basal aperture is intermediate in size.In addition, the absence of an accessory piece in the copulatory complex appears to represent a secondary evolutionary loss within this group of parasites.For example, the MCOs of species lacking an accessory piece, such as in E. spirotubiforum (Fig. 164), E. adelpha (Figs 168,169), E. paululum (Fig. 180), and E. youngi (Figs 186,187), appear most similar to those of E. ferocis (Fig. 146) and E. fatuum (Fig. 94), both species of which possess an MCO associated with a small accessory piece.Because morphology of the copulatory complex no longer appears diagnostic at the generic level, the diagnosis of Euryhaliotrema was expanded to include the valid species of Euryhaliotrematoides and Aliatrema, and the two latter genera were considered subjective synonyms of Euryhaliotrema.As a result of the proposed synonymies, the species previously assigned to Euryhaliotrematoides and Aliatrema were transferred to Euryhaliotrema as new combinations.
Studies involving phylogenetic analyses using molecular data have provided minimal and often conflicting evidence regarding the validities of Euryhaliotrema, Aliatrema and Euryhaliotrematoides.While some of these studies have suggested possible monophyly of species parasitizing particular host groups, all have been based on comparatively few taxa that clearly underestimated species diversity.As a result, potential bias toward closely related species parasitizing specific host groups has likely occurred.For example, the analysis conducted by PLAISANCE et al. (2005) using 28S rDNA sequences of only seven species of Euryhaliotrematoides and Aliatrema cribbi (all from chaetodontid hosts) and Euryhaliotrema chrysotaeniae (from a lutjanid host), suggested that Euryhaliotrematoides was monophyletic, with Euryhaliotrema (represented by E. chrysotaeniae) serving as sister group of Euryhaliotrematoides + Aliatrema (see their fig.2B).On the other hand, their analysis using 18S rDNA sequences showed Euryhaliotrematoides to be polyphyletic (see fig. 2A in Plaisance et al. 2005).WU et al. (2006) found Euryhaliotrema johni, Haliotrema spirotubiforum and Euryhaliotrema sp.ZHDDb (all parasites of lutjanids) to form a "monophyletic" clade in their analysis of rDNA and, as a result, transferred H. spirotubiforum, a species lacking an accessory piece and having a funnel-shaped base of the MCO, to Euryhaliotrema.Later, WU et al. (2007), using sequences from fifteen dactylogyrid species herein assigned to Euryhaliotrema (sensu lato), suggested that the species infesting chaetodontid, lutjanid and sparid hosts represented a major clade (their lineage 2).While their analysis suggested a monophyletic Euryhaliotrematoides, which included 7 species infesting chaetodontids and 1 from a lutjanid, it did not provide support for the monophyly of either Euryhaliotrema or Aliatrema (WU et al. 2007).Finally, KRITSKY et al. (2009a) suggested a monophyletic Euryhaliotrematoides comprising only four species from chaetodontid hosts but failed to justify Euryhaliotrema, while DANG et al. (2010), using sequences available in GenBank, indicated that Aliatrema and Euryhaliotrematoides were monophyletic within a clade containing a paraphyletic Euryhaliotrema and two species of Haliotrema Johnston & Tiegs, 1922.A common relationship that emerged from all of the studies employing molecular data, however, was a major clade comprising the species of all three genera, suggesting that Euryhaliotrema, Euryhaliotrematoides and Aliatrema together com-prised a monophyletic taxon.These findings further support the proposed synonymies of the three genera, with Euryhaliotrema having priority.
Haliotrema monoporosum Pan & Zhang, 2000 was described in PAN (2000) from Chaetodon wiebeli (Chaetodontidae) collected off Wanning, Hainan Island (South China Sea), China, and characterized in part by possessing a perforation through a "swelling" near the midregion of the ventral bar.PLAISANCE & KRITSKY (2004) suggested that the species was probably valid, that it was differentiated from the similar Euryhaliotrematoides grandis (now Euryhaliotrema grandis) by the perforated ventral bar, and although a transfer was not made, that the species probably belonged to Euryhaliotrematoides. Examination of 19 voucher specimens (USNPC 105461) obtained from the gills of Chaetodon ornatissimus collected off Moorea, French Polynesia, by L. Plaisance and colleagues for their studies on the Monogenoidea of chaetodontid fishes, revealed that the species possessed the morphological features required to place it in Euryhaliotrema as revised herein.Thus, it is transferred as Euryhaliotrema monoporosum (PAN & ZHANG 2000) comb.nov.Chaetodon ornatissimus represents a new host record for the species.
Two other dactylogyrid species, previously described from lutjanid or chaetodontid hosts, are herein considered species inquirendae.The original descriptions of both Protancyrocephalus rangusi Gupta & Khanna, 1974 from the gills of Lutjanus rangus (Cuvier) (now L. bohar), Lutjanidae, off Port Blair (Andaman and Nicobar islands), India, and Daitreosoma chaetodontis Reichenbach-Klinke, 1959 from the gills of Chaetodon collare, Chaetodontidae, imported into Germany in 1958 are inadequate for species identification and appropriate generic placement.Attempts to locate type specimens of both species failed and it is presumed that they have been lost or destroyed (S.Klimpel and N. Agrawal, personal communications).
The assignment of the species from C. collare to Daitreosoma Johnston & Tiegs, 1922by REICHENBACH-KLINKE (1959) is clearly erroneous.Daitreosoma is a subjective synonym ZOOLOGIA 29 (3): 227-276, June, 2012 of Protogyrodactylus Johnston & Tiegs, 1922, which is characterized in part by species having an accessory sclerite associated with the tip of the superficial root of the ventral anchor (see GALLI & KRITSKY 2008).REICHENBACH-KLINKE's (1959) illustration clearly shows that an accessory sclerite is absent in D. chaetodontis.Although GUPTA & KHANNA (1974) indicate that haptoral bars are absent in P. rangusi, the original drawings are so incomplete and diagrammatic that assignment of the species to Protancyrocephalus Bychowsky, 1957 is also problematical.Based on GUPTA & KHANNA's (1974) description of the species, P. rangusi could just as easily be assigned to Euryhaliotrema, Haliotrematoides or Tetrancistrum Goto & Kikuchi, 1917, all of which contain species parasitizing lutjanid hosts (KRITSKY et al. 2007(KRITSKY et al. , 2009a, nobis), nobis).That the type species of Protancyrocephalus, Protancyrocephalus strelkowi Bychowsky, 1957, was described from a member of the Pleuronectidae, a pleuronectiform family unrelated to the Lutjanidae, further suggests that the original assignment of P. rangusi to the genus is erroneous.
Because type specimens would be required to establish the validity and taxonomic position of both D. chaetodontis and P. rangusi and that these specimens have apparently been lost or destroyed, demonstrates the importance of preserving such specimens (including voucher specimens) used in development of published reports in an established museum.Without the original reference material, it is highly unlikely that the status of the two species as species inquirendae will ever change and that they will ever be rediscovered during surveys of parasites of their respective hosts.Indeed, examination of L. bohar for the present study did not reveal any dactylogyrid specimens that could be assigned to P. rangusi based on the description by GUPTA AND KHANNA (1974).Deposition of voucher specimens in established museums should not only occur for studies dealing with the taxonomy of respective groups but also should be done when species are recorded from various hosts and localities in ecological and phylogenetic studies.For example, the geographic records of Euryhaliotrema species reported in VIGNON et al. (2009) for their investigation on ecological affects of alien introductions and those reported by WU et al. (2006WU et al. ( , 2007) ) for their phylogenetic studies using molecular data, cannot be verified because representative voucher specimens were not preserved.
Measurements: Table II.
Remarks: This species was originally described as Haliotrema tubocirrus from the gills of Lutjanus synagris (type species), L. analis, L. apodus, L. cyanopterus and Rhomboplites aurorubens from the environs of Havana, Cuba by ZHUKOV (1976).Three other lutjanid species from Puerto Rico, L. vivanus, L. griseus and L. buccanella, were recorded as new hosts for the parasite by BOSQUES RODRÍGUEZ (2004), who regarded E. tubocirrus to be the least host specific of the dactylogyrid species infesting lutjanids in the region.Two additional hosts, L. campechanus and L. jocu, were recorded for the parasite during the present survey, which would appear to support the hypothesis of BOSQUES RODRÍGUEZ (2004).KRITSKY & BOEGER (2002) transferred this species to Euryhaliotrema based on the description and drawings provided in the original description by ZHUKOV (1976).Euryhaliotrema  ZAMBRANO et al. 2003, FUENTES ZAMBRANO & SILVA ROJAS 2006).
Measurements: Table III.Remarks: Euryhaliotrema fastigatum was originally described from the gills of grey snapper from the southern Gulf of Mexico near Havana, Cuba, by ZHUKOV (1976), who also reported it from Lutjanus apodus, L. jocu and L. analis.During the present survey, morphological distinctions between specimens of E. fastigatum collected from grey snapper and the yellow snapper, L. argentiventris, were not evident.Nonetheless, the identification of those from L. argentiventris as E. fastigatum was considered provisional.Specimens of the yellow snapper were obtained from the eastern Pacific off Panama and it is unlikely that conspecific specimens of a species of Euryhaliotrema would naturally occur on opposite sides of North America, areas that have been isolated since the uprising of the Panamanian Isthmus about 3.2 mya.The possibility exists that the eastern Pacific populations of the helminth represent a cryptic sisterspecies of E. fastigatum occurring on the Atlantic side of North America.That the populations occurring in the Gulf of Mexico and eastern Pacific Ocean probably represent separate species is supported by evidence that the host fishes have speciated following the Panamanian uprising and that geminate species pairs in other monogenoidean groups apparently occur along the Pacific and Atlantic sides of North America (KRITSKY & MENDOZA-FRANCO 2008, KRITSKY et al. 2009b, MENDOZA-FRANCO et al. 2009, KRITSKY 2012).Assignment of a new species name to ZOOLOGIA 29 (3): 227-276, June, 2012 the Pacific counterpart is not made at this time in order to minimize possible unnecessary synonyms.
Euryhaliotrema fastigatum resembles a number of congenerics, including E. cardinale, E. cognatus, E. diplops and E. tormocleithrum, by having a thinning of the base of the dorsal anchor near its junction with the anchor shaft.It most closely resembles E. diplops by having longitudinal grooves along the surfaces of the anchor points and shafts but differs from this and other similar species by lacking an articulation process in the copulatory complex.
FUENTES ZAMBRANO & SILVA ROJAS (2006) described Euryhaliotrema griseus from the grey snapper, L. griseus, off Venezuela.This species is considered a junior subjective synonym of E. fastigatum based on their mutual host and likeness of the original drawings of E. griseus and those of E. fastigatum.
Remarks: This species has not been reported since its original description from L. apodus off Havana, Cuba, by ZHUKOV (1976).Although BOSQUEZ RODRÍGUEZ (2004) examined 7 specimens of L. apodus as well as members of twelve other lutjanid species for helminth parasites, E. paracanthi was not found on these hosts from the marine waters off Puerto Rico.Euryhaliotrema paracanthi is easily differentiated from other species of Euryhaliotrema infesting lutjanid hosts by possessing a subterminal spine or hook on the accessory piece.
The identification of specimens collected from L. argentiventris from the eastern Pacific off Panama as E. paracanthi during the present study was considered provisional.Like E. fastigatum on this host, the specimens from western Panama may represent a cryptic species that is nearly identical morphologically to E. paracanthi from the Gulf of Mexico.The two species may represent another example of a geminate species pair off North America that developed as a result of the uprising of the Panamanian Isthmus.Assignment of a new species name to the Pacific counterpart is not made at this time in order to minimize possible unnecessary synonyms.
Remarks: Four E. torquecirrus were recovered in association with several Haliotrematoides heteracantha (Zhukov, 1976) Kritsky, Yang & Sun, 2009 (USNPC 105465, FSBC-I 093787) from the gills of its type host, Ocyurus chrysurus, collected from the open Gulf of Mexico off Florida.The morphology of the haptoral and copulatory sclerites of these specimens corresponded to that originally described for the species by ZHUKOV (1976) and that of available specimens collected by Dr. Zhukov near Havana, Cuba (USNPC 91432).Although satisfactory for specific identification, the specimens were insufficient to provide a needed redescription of the species.
Euryhaliotrema torquecirrus most closely resembles E. perezponcei from the spotted rose snapper, L. guttatus, from off the western coast of southern North America and also may be confused with E. tubocirrus parasitizing various lutjanids occurring off the eastern coast of the continent.It differs from E. perezponcei by lacking a submedial branch on one component of the accessory piece and by having slightly more robust haptoral anchors.It is easily distinguished from E. tubocirrus by the comparative morphologies of the respective copulatory complexes.In E. torquecirrus, the coil of the MCO comprises a minimum of three rings (about two rings in E. tubocirrus), and the accessory piece includes two (apparently unarticulated) components (accessory piece of E. tubocirrus with multiple branches).Euryhaliotrema torquecirrus and E. perezponcei apparently represent another example of a geminate species pair occurring off the eastern and western coasts of North America, respectively.
Euryhaliotrema longibaculum (Zhukov, 1976) Kritsky & Boeger, 2002  Syn.Haliotrema longibaculum Zhukov, 1976 Redescription: Body proper fusiform to subtriangular, slightly flattened dorsoventrally; greatest width in posterior trunk at level of testis.Tegument smooth.Cephalic region broad; cephalic lobes poorly developed.Four eyespots; members of posterior pair of eyespots slightly larger, closer together than those of anterior pair; accessory chromatic granules un-common in cephalic and anterior trunk regions.Pharynx spherical.Peduncle broad, slightly tapered posteriorly; haptor subrectangular to trapezoidal.Ventral anchor with broad superficial root, small to nonexistent deep root, elongate point extending past level of tip of superficial root; dorsal anchor with elongate straight superficial root, short to nonexistent deep root, delicate elongate point extending past level of tip of superficial root; shaft of both anchors with irregular diameter, angular bend near its midlength.Ventral bar an elongate broadly V-shaped rod, inverted or not.Dorsal bar a straight rod with slight twist near midlength and with expanded ends.Hook with uniform shank, upright acute thumb; FH loop about shank length.MCO a U-shaped tube with funnel-shaped base.Accessory piece comprising variably flattened rod attached to base of MCO by articulation process.Gonads tandem or slightly overlapping (germarium ventral when overlapped).Testis ovate; seminal vesicle an elongate dilation of distal vas deferens; prostatic reservoir small, lying to right and posterior to MCO.Germarium ovate; oviduct, ootype, uterus and Mehlis' gland not observed; vaginal pore marginal; vaginal vestibule with internal sclerotized wall; vaginal canal indistinct along most of its length; seminal receptacle small, lying immediately anterior to germarium.Vitellaria dense, coextensive with gut; transverse vitelline duct anterior to seminal receptacle.Egg not observed.
Remarks: Haliotrema longibaculum was described by Zhukov (1976) from the gills of L. synagris and L. mahogoni from the Gulf of Mexico off Havana, Cuba.The species was transferred to Euryhaliotrema by KRITSKY & BOEGER (2002) based solely on Zhukov's original description and drawings, the latter of which suggested that the MCO had a bulbous base, at that time, the defining character of Euryhaliotrema.However, specimens of this species collected for the present study indi- tion process in the copulatory complex connecting the accessory piece to the base of the MCO (articulation process absent, MCO and accessory piece non-articulated in E. fatuum).
The original description of this species (as Haliotrema longibaculum) by ZHUKOV (1976) was based on ten specimens from the lane snapper, L. synagris, while the original figures were made of a specimen obtained from the mahogony snapper, L. mahogoni, both fishes of which were collected off Cuba.Although ZHUKOV (1976) designated a "type specimen" and deposited it as No. 5505 in the helminth collection of the Zoological Institute, Russian Academy of Sciences, St. Petersburg, Russia, he did not specifically designate or mention the type host when he proposed the species.According to Dr. Pavel Gerasev of the Zoological Institute in St. Petersburg, the host of the holotype (ZIS 5505) was the mahogany snapper, which is therefore considered the type host of the species.
Remarks: The specimens assigned to this species and collected from spotted rose snapper off Panama were initially identified as Euryhaliotrema longibaculum.Recently, SOLER-JIMÉNEZ et al. (2012) described Euryhaliotrematoides mehen for specimens collected from spotted rose snapper off the Pacific coast of Mexico.These authors recognized the morphological simila-rity of the two species, stating that E. mehen differed from E. longibaculum by differences in the morphology of the copulatory complex, anchors and bars.Most significantly, SOLER-JIMÉNEZ et al. (2012) reported the copulatory complex of E. mehen to have a tubular MCO with a thickened fleshy edge of the base and a membranous accessory piece enveloping the distal portion of the MCO like a scarf.However, examination of four paratypes deposited in the USNPC (194737-740) by SOLER-JIMÉNEZ et al. (2012) (2 specimens stained in Gomori's trichrome & 2 specimens mounted unstained in Gray & Wess medium) suggested that the "scarf" represents the interior wall of the genital atrium into which portions of the accessory piece are incorporated; the accessory pieces of the two unstained specimens are morphologically identical to those of present specimens from Panama (see Fig. 38).The base of the MCO possesses a small inner cavity that may impart what appears to be a thickened, low density wall of the base; the cavity is not apparent in all specimens, suggesting that the character is not sufficient to differentiate the two species.Finally, differences observed in the anchors and bars of the two species were minimal and easily fall within expected intraspecific variation among dactylogyrids.The only remaining criterion for separating E. mehen from E. longibaculum is the respective geographic and host ranges.In order to prevent unwarranted synonyms, E. mehen is provisionally accepted as a valid species until the impact of the Panamanian Isthmus on speciation within this group of parasites is determined.Because Euryhaliotrema and Euryhaliotrematoides are herein considered synonyms, it remains necessary, however, to transfer Euryhaliotrematoides mehen to Euryhaliotrema as a new combination.

Euryhaliotrema fajeravilae
Kritsky & Mendoza-Franco sp.nov.Description: Body proper gently tapering anteriorly from peduncle; greatest width along peduncle.Tegument smooth.Cephalic region broad; cephalic lobes poorly to moderately developed.Four eyespots; one member of anterior pair frequently dissociated; members of posterior pair with lenses, subequal and equidistant compared to members of anterior pair; accessory chromatic granules few or absent in cephalic and anterior trunk regions.Pharynx spherical.Peduncle broad; haptor globose.Ventral anchor with moderately long superficial root, short deep root, curved shaft, elongate point extending past level of tip of superficial root.Dorsal anchor with elongate uplifted superficial root, small deep root, curved shaft, elongate point extending past level of tip of superficial root.Ventral bar broadly V shaped, with expanded ends; dorsal bar a slightly curved or straight rod with small terminal enlargements.Hook with uniform shank, upright acute thumb; FH loop about shank length.MCO a U-shaped tube with enlarged funnelshaped base.Accessory piece variable; articulation process con-necting accessory piece with base of MCO.Testis ovate; seminal vesicle large, fusiform; prostatic reservoir not observed.Germarium pyriform; oviduct, ootype, uterus not observed; vaginal pore marginal at small indentation of tegument; vaginal canal inconspicuous; seminal receptacle not observed.Vitellaria dense, coextensive with gut; transverse vitelline duct anterior to germarium.Egg not observed.
Type host and locality: Yellow Etymology: This species is named in honor of our friend and colleague, Dr. Emma J. Fajer-Ávila, Unidad Mazatlán en Acuicultura y Manejo Ambiental, Mazatlán, Sinaloa, Mexico, in recognition of her contributions on the monogenoidean parasites of lutjanids in Mexico.
Remarks: This species is one of a complex of Euryhaliotrema species infecting lutjanids and distributed on either side of southern North America.It differs from the other two members of the complex, E. longibaculum and E. mehen, by having larger anchors and a noticeably smaller copulatory complex.
Remarks: Euryhaliotrema perezponcei could be confused with E. torquecirrus by having similar anchors and dorsal bars.It differs from the latter species by having one component of the accessory piece of the copulatory complex with a proximal rounded branch (absent in E. torquecirrus), a shorter MCO, and a broadly W-shaped ventral bar (ventral bar comparatively straight in E. torquecirrus).The two species may represent sister species or a geminate species pair, each member of which is separated from the other by the Panamanian Isthmus.
Remarks: Euryhaliotrema anecorhizion was collected from the gills of the yellow snapper in association with six other species of Euryhaliotrema, including E. cf.fastigatum, E. cf.longibaculum, E. cf.paracanthi, E. fajeravilae and 2 undescribed species (USNPC 105463, 105464).It is closest morphologically to E. fastigatum in the general morphology of the MCO and by having the points and shafts of the dorsal and ventral anchors with longitudinal superficial grooves.It differs from E. fastigatum by having an articulation process in the copulatory complex that attaches the accessory piece to the base of the MCO and from all other congeneric species by having a comparatively short upturned superficial root of the dorsal anchor.

Figs 64-71
Description: Body proper fusiform, gently tapered anteriorly from level of gonads; greatest width at level of gonads.Tegument smooth.Cephalic region broad; cephalic lobes poorly to moderately developed.Eyespots two (anterior pair absent), each with lenses; random accumulations of accessory chromatic granules common in cephalic, anterior trunk regions.Pharynx subspherical.Peduncle short, broad; haptor globose.Ventral anchor with depressed superficial root terminating acutely, short to nonexistent deep root, short curved shaft, elongate strongly recurved point extending past level of tip of superficial root.Dorsal anchor with delicate base (frequently folded) having inconspicuous fracture line, elongate superficial root, and short to nonexistent deep root; shaft short; elongate recurved point extending past level of tip of superficial root.Shafts and points of both anchors with longitudinal superficial grooves.Ventral bar a straight rod with knobbed ends and slender spine-like posteromedial projection; dorsal bar a slightly curved rod usually with small anteromedial and posteromedial pustules (anterior pustule more frequently lacking).Hook delicate, with uniform shank, upright acute thumb; FH loop nearly shank length.MCO having a bulbous base and a coiled flattened tubular shaft of about three counterclockwise rings.Accessory piece comprising variable terminal structure with articulation process extending within rings to bulbous base of MCO.Etymology: The specific name (a noun) is from Greek (diploos = two + ops = eye) and refers to the presence of two (one pair) eyespots.

Euryhaliotrema hainanense
Remarks: Euryhaliotrema hainanense closely resembles E. xinyingense, both species of which parasitize the gills of mangrove red snapper.Differentiation of the two species, based on available specimens, is provided in the Remarks for E. xinyingense.
Remarks: ZHANG (2001) described this species as Haliotrema anguiformis based on six specimens collected from the gill filaments of L. vaigiensis (now L. fulvus) and L. russellii from Guangdong and Hainan Provinces in China.His drawings of the haptoral and particularly the copulatory sclerites (figs 10-5A-B in ZHANG 2001) suggest that he was dealing with a minimum of two different dactylogyrid species, both of which clearly belong in Euryhaliotrema.Later, WU et al. (2007) reported collecting the species from L. monostigma from Guangdong Province in China for their investigation on the monophyly of the Ancyrocephalinae using rDNA sequence data; based on the results of their phylogenetic analyses, WU et al. (2007) transferred the species to Aliatrema Plaisance & Kritsky, 2004.Because of Zhang's apparent clumping of specimens apparently representing more than one putative species, all published host and locality records as well as the identity of the species remain uncertain.Examination of the type specimens, particularly the holotype, will be necessary to determine which form represents the species and whether or not all paratypes are conspecific.Confirmation of the record of WU et al. (2007) will require examination of new material from L. monostigma from the environs of Guangdong, China, as these authors appar-ZOOLOGIA 29 (3): 227-276, June, 2012 ently failed to preserve voucher specimens of their form in a museum collection.No specimens of this species, including the type specimens, were available for the present study.Nonetheless, the species is transferred to Euryhaliotrema as Euryhaliotrema anguiformis (Zhang, 2001)    Remarks: LI et al. (2005) placed this species in Haliotrema when they described it from the gills of the mangrove red snapper from the South China Sea.Although museum specimens were not available and the species was not collected during the present study, it clearly is a valid species having a copulatory complex lacking an accessory piece associated with the elongate proximally straight MCO.The species is transferred to Euryhaliotrema as E. nanaoense (Li, Yan, Yul, Lan & Huang, 2005) comb.nov.based on the general morphology of the reproductive system and haptoral sclerites as depicted by LI et al. (2005).Euryhaliotrema nanaoense belongs to the group of congenerics that lack an accessory piece and whose species include E. spirotubiforum, E. adelpha, E. paululum and E. youngi, all parasites of lutjanids from the eastern hemisphere.Based on haptoral morphology, it is most similar to E. youngi, from which it differs primarily in the morphology of the MCO (MCO comprising a loose coil of slightly more than one ring in E. youngi).

Figs 84-90
Description: Body proper fusiform; greatest width at level of gonads.Tegument smooth.Cephalic region slightly tapered anteriorly, broad; cephalic lobes well developed.Eyespots four; members of posterior pair with lenses, larger, closer together than those of anterior pair; accessory chromatic granules few (or absent) in cephalic, anterior trunk regions.Pharynx subspherical.Peduncle broad; haptor globose, usually directed ventrally from plane of trunk.Anchors similar, members of anterior pair slightly more robust than those of posterior pair; each with depressed moderately long superficial root, short to nonexistent deep root, short slightly curved shaft, elongate strongly recurved point extending past level of tip of superficial root; distal shafts and points of both anchors with longitudinal superficial grooves.Bars similar; each a broadly V-shaped rod with knobbed ends.Hook delicate, with uniform shank, upright acute thumb; FH loop nearly shank length.MCO  Etymology: The specific name (a noun) is from Greek (kryptos = hidden + phallos = penis) and refers to the cryptic copulatory complex.
Remarks: Euryhaliotrema cryptophallus may be somewhat difficult to identify because of its dense vitelline follicles that usually mask the delicate and lightly sclerotized copulatory complex.It most closely resembles E. anecorhizion in the general morphology of the haptoral sclerites and copulatory complex.It differs from this species by having superficial roots of both anchors noticeably depressed (superficial anchor roots, especially those of the dorsal anchors, upturned in E. anecorhizion) and by having only one ring in the copulatory complex (about two rings in E. anecorhizion).In addition, E. cryptophallus lacks an articulation process connecting the accessory piece to the base of the MCO (articulation process present in E. anecorhizion).
Remarks: Type specimens of E. lutjani were not available and the species was not collected during the present investigation.The original description lacks morphological detail (see LI 2006) that would allow its separation from some of the other species described from lutjanids from the western Pacific Ocean.The species requires redescription based on the type specimens and perhaps freshly collected material from the western Pacific region (see below).Remarks: Euryhaliotrema guangdongense differs from all known species of Euryhaliotrema by possessing a coiled MCO with 8-9 counterclockwise rings (all remaining congenerics possess six or fewer rings in the MCO).The species was not collected during the present study, and the type specimens were not available for study.
Remarks: The original description of this species as Ancyrocephalus johni from Lutjanus johnii in India by TRIPATHI (1959) is inadequate, and the species requires redescription.While it was not collected during the present study and redescription is not currently possible, illustrations of the haptoral and copulatory sclerites obtained from four of YOUNG's (1968) voucher specimens of the species deposited in the USNPC (61273) were presented by KRITSKY & BOEGER (2002).Based on these drawings, Euryhaliotrema johni most closely resembles E. lutiani.Both species have an MCO with an elongate bananashaped base and short coiled tubular shaft of approximately one ring.Euryhaliotrema johni differs from E. lutiani in the comparative morphology of the anchors, vagina and accessory piece.In E. johni, the bases of the ventral and dorsal anchors are elongate (bases of both anchors comparatively shorter in E. lutiani), the roots of the dorsal anchor are poorly defined (well defined in E. lutiani), the vagina is comparatively long (short in E. lutiani) and the accessory piece lacks a distal hook-like modification (present in E. lutiani).
Remarks: This species was not collected during the present study.The haptoral and copulatory sclerites of E.lutiani were illustrated by KRITSKY & BOEGER (2002) based on the holotype and five paratypes deposited in the Meguro Parasitological Museum (MPM), Tokyo, Japan (MPM 22640).Differentiation of the species from its most similar congeneric, E. johni, is presented in the Remarks of the latter species.The record by WANG (1997) of E. lutiani on the gills of Lutjanus vitta requires confirmation; the ventral anchors depicted in fig.3a of WANG (1997) suggest that this author had specimens of E. johni (see Remarks for E. johni).
Remarks: This species resembles E. mehen, E. fajeravilae and E. longibaculum, all parasites of lutjanids from the western hemisphere, by the comparative morphology of the haptoral anchors and bars.It differs from the three species by lacking an articulation process connecting the accessory piece to the base of the MCO and by having a sharp recurve of the shaft at its origin from the base in the MCO.Etymology: The specific name (an adjective) is from Latin (cardinis = a hinge + -alis = pertaining to) and refers to the diagonal thin of the base that allows dorsoflexion of the dorsal anchor.
Remarks: Euryhaliotrema cardinale resembles the following species by having a thinning of the base of the dorsal anchor that allows dorsoflexion of the anchor shaft and point toward the tip of the superficial root: E. fastigatum, E. distinctum, E. tormocleithrum, E. ramulum, E. cognatus and E. diplops, all of which are parasites of lutjanid hosts.It differs from E. fastigatum ZOOLOGIA 29 (3): 227-276, June, 2012 by possessing an articulation process connecting the accessory piece to the base of the MCO, and is easily differentiated from E. distinctum and E. tormocleithrum by lacking modifications of the superficial root of the ventral anchor (Figs 124,126), from E. diplops by having two pairs of eyespots and fewer rings in the coiled male copulatory organ (approximately one and a half rings in E. cardinale and about three rings in E. diplops) and from E. ramulum by lacking bifurcated ends of the ventral bar.It most closely resembles E. cognatus in the general morphology of the haptoral sclerites but differs from it by having a greater diameter of the basal ring of the more delicate tubular shaft of the MCO (Fig. 115).
Euryhaliotrema chrysotaeniae (Young, 1968) Kritsky & Boeger, 2002  to Euryhaliotrema by KRITSKY & BOEGER (2002), who based the transfer on their examination of the two type specimens (USNPC 61274, 61275).The original description is adequate except that YOUNG (1968) indicated that only 12 hooks were observed in the haptor of the two preserved type specimens.Based on his drawing of the holotype [fig.7(a)], YOUNG (1968) apparently missed the members of hook pair 5 which lie near the level of the shafts and points of the ventral anchors.Examination of the unstained specimens collected during the present study demonstrated that the species possesses the full complement of 14 hooks (7 pairs) normally present in dactylogyrid species (MIZELLE & PRICE 1963), although hook pair 5 is often difficult to find in some specimens depending on the position and orientation of the ventral anchors.
Euryhaliotrema chrysotaeniae differs from all other congenerics by possessing a coiled MCO with three to four clockwise rings; in all other congenerics, the coiled MCO is counterclockwise.The direction of the coil is correctly shown in the drawings of the MCO (ventral views) of both YOUNG (1968) and KRITSKY & BOEGER (2002) and is verified in the present collection of specimens (Fig. 108, dorsal view).
The present record of E. chrysotaeniae on the gills of L. fulviflamma from New Caledonia requires confirmation, as it is based on a single damaged specimen with the haptor torn away.Verification of the record will involve collection and examination of complete specimens from the dory snapper from New Caledonia, in order to verify haptoral morphology.

Figs 112-118
Description: Body proper fusiform; greatest width usually in posterior trunk at level of testis.Tegument smooth.Cephalic region broad; cephalic lobes moderately developed.Four eyespots; members of posterior pair with lenses, equidistant and larger than members of anterior pair; few accessory chromatic granules in cephalic region.Pharynx spherical.Peduncle broad, slightly tapered posteriorly; haptor subhexagonal, with lateral lobes.Ventral anchor with short superficial root, knob-like deep root, curved moderately long shaft, point extending past level of tip of superficial root.Dorsal anchor with elongate superficial root, poorly developed deep root, curved shaft, point extending past level of tip of superficial root; base with diagonal hinge, proximal portion frequently bent toward midline of haptor at hinge.Ventral bar a slightly curved rod with enlarged ends; dorsal bar straight, with ends directed posterolaterally.Hook with uniform shank, upright acute thumb; FH loop about shank length.Tubular coiled shaft of MCO having about two counterclockwise rings originating from bulbous base.Accessory piece comprising variable sheath along distal shaft of MCO; articulation process within rings of male copulatory complex.Testis ovate; proximal vas deferens not observed; seminal vesicle subspherical, lying immediately posterior to MCO; ejaculatory duct looping anteriorly from semi-nal vesicle before entering base of MCO; prostatic reservoir small, lying to left of base of MCO.Germarium pyriform; oviduct, ootype, uterus not observed.Vaginal pore marginal; vaginal vestibule with wall having variably sclerotized regions; vaginal canal funnel shaped, narrowing to fine duct before entering medial seminal receptacle.Vitellaria dense; transverse vitelline duct anterior to seminal receptacle.Egg not observed.
Etymology: The specific name (a noun) is from Latin (cognatus = a relative) and refers to the species relationship with other members of Euryhaliotrema.
Remarks: The copulatory complex of E. cognatus resembles those of E. monacanthus and E. thatcheri, both parasites of freshwater sciaenids, Plagioscion spp., in South America.It differs from these species by possessing an articulation process connecting the accessory piece to the bulbous base of the MCO (accessory piece and MCO unarticulated in E. monacanthus and E. thatcheri).It differs further from E. monacanthus by having ventral and dorsal anchor/bar complexes in the haptor (dorsal anchor/bar complex absent, apparently representing a secondary loss, in E. monacanthus).

Figs 119-124
Description: Body proper fusiform; greatest width in anterior trunk at level of copulatory complex.Tegument smooth.Cephalic region broad; cephalic lobes well developed.Single pair of eyespots, each with conspicuous lens; accessory chromatic granules small, ovate, uncommon in cephalic region.Pharynx subspherical to subovate.Peduncle broad; haptor subhexagonal, with lateral lobes.Ventral anchor robust, lacking deep root, with short depressed superficial root, heavy shaft constricted distally, elongate point extending past level of tip of superficial root; point with longitudinal superficial ridges.Dorsal anchor with elongate superficial root, poorly developed deep root, robust straight irregular shaft; point extending slightly past level of tip of superficial root; base with diagonal hinge, proximal portion may be bent toward body midline at hinge; point with longitudinal superficial ridges.Ventral bar rod shaped, with bifurcated ends and anteromedial rectangular ridge; dorsal bar straight, subtrapezoidal, anterior margin shorter than posterior margin.
Hook with uniform shank, upright acute thumb; FH loop about shank length.MCO a coil of about one counterclockwise ring originating from broad cone-shaped base.Accessory piece comprising variable distal sheath; articulation process present within ring of shaft of MCO.Testis elongate ovate; proximal vas deferens not observed; indistinct seminal vesicle lying sinistroposterior to base of MCO; prostatic reservoir not observed.Germarium bacilliform; oviduct, ootype, uterus not observed.Vaginal pore marginal; vagina, seminal receptacle not observed.Vitellaria dense.Egg not observed.Etymology: The specific name (an adjective) is from the Latin distinctus (separate, different) and refers to the unique copulatory complex and anchors.
Remarks: Euryhaliotrema distinctum differs from all congeneric species by its unique anchors and large cone-shaped base of the MCO.Although only two specimens of this species were collected from the two-spot red snapper off the Maldive Islands, the unique features of the anchors and copulatory complex justify proposal of the form as a new species of Euryhaliotrema.

Figs 125-131
Description: Body proper fusiform; greatest width usually in posterior trunk at level of testis.Tegument smooth.Cephalic region broad; cephalic lobes moderately to poorly developed; anterior trunk narrowed.Four eyespots; members of respective pairs equidistant; posterior eyespots with lenses, larger than members of anterior pair; accessory chromatic granules ovate, variable in size, scattered throughout cephalic and anterior trunk regions.Pharynx ovate.Peduncle short, broad, tapered posteriorly; haptor subhexagonal, with bilateral lobes.Ventral anchor with short depressed superficial root, small knob-like deep root, evenly curved shaft and point; point extending well past level of tip of superficial root; anchor base with medial depression receiving ends of ventral bar.Dorsal anchor with elongate superficial root, poorly developed deep root, long curved shaft, point extending slightly past level of tip of superficial root; base with diagonal hinge, proximal portion of base occasionally bent at hinge toward midline of haptor.Ventral bar robust, with posteromedial triangular protuberance with medial perforation; dorsal bar a straight rod, frequently with medial constriction.Hook with uniform shank, upright acute thumb; FH loop about shank length.MCO with funnelshaped base, coiled tubular shaft having about one and one half counterclockwise rings.Accessory piece comprising variable sheath along distal portion of shaft of MCO; articulation process united with proximal end of accessory piece.Testis ovate; vas deferens, seminal vesicle, prostatic reservoir not ob-served.Germarium bacilliform; oviduct, ootype, uterus not observed; Mehlis' gland well developed.Vaginal pore marginal at level of germarium; vaginal canal not observed.Vitellaria dense; bilateral vitelline ducts confluent anterior to germarium.Egg not observed.
Etymology: The specific name (a noun) is from Greek (tormos = a hole + kleithron = a bar) and refers to the ventral bar.
Remarks: Available specimens of E. tormocleithrum were in generally poor condition.Nonetheless, the species is easily separated from all congeners except E. monoporosum by having a ventral bar with a perforated posteromedial protuberance and a ventral anchor with a reduced superficial root and a medial cavity in the base receiving the ends of the ventral bar.The new species is differentiated from E. monoporosum, a parasite of chaetodontid fishes, by possessing haptoral anchors with elongate shafts and points.In addition, the superficial root of the dorsal anchor is long and delicate in E. tormocleithrum, while the corresponding root in E. monoporosum is comparatively short and thickset.
Euryhaliotrema ramulum Kritsky & Galli sp.nov.ZOOLOGIA 29 (3): 227-276, June, 2012 frequently bent at hinge toward midline of haptor.Ventral bar rod shaped, with bifurcated ends; dorsal bar straight, with slightly enlarged ends directed posterolaterally.Hook with uniform shank, upright acute thumb; FH loop about shank length.MCO with bulbous base, coiled tubular shaft of nearly two counterclockwise rings.Accessory piece comprising variable sheath along distal shaft of MCO; articulation process present within rings of male copulatory complex.Testis ovate; proximal vas deferens not observed; seminal vesicle tear-drop shaped, lying sinistroposterior to base of MCO; prostatic reservoir not observed.Germarium bacilliform; oviduct, ootype, uterus not observed.Vaginal pore dextromarginal; vaginal canal a narrow duct leading to seminal receptacle immediately anterior to germarium.Vitellaria dense; bilateral vitelline ducts confluent slightly anterior to seminal receptacle.Egg not observed.
Etymology: The specific name (a noun) is from the Latin ramus (a branch) appended to the diminutive suffix (-ulus) and refers to the ends of the ventral bar.
Remarks: Although fairly abundant on the gills of the humpback red snapper examined during the present study, available specimens of E. ramulum were in generally poor condition.The species is easily differentiated from all other congenerics by having a ventral bar with bifurcated ends.Etymology: The specific name (an adjective) is from Latin (simplex = simple) and refers to the comparatively common and unmodified haptoral and copulatory sclerites.
Remarks: This species closely resembles E. fatuum, from which it differs by having well-developed deep roots of the dorsal anchors (deep roots poorly developed in E. fatuum), a Vshaped ventral bar (ventral bar broadly U shaped with ends directed laterally in E. fatuum), and by lacking a proximal bend of the shaft of the MCO (present in E. fatuum).In addition, the haptoral anchors are measurably smaller in E. simplicis.Etymology: The specific name (an adjective) is from Latin (ferox = bold) and refers to the robustness of the species.
Remarks: Most of the available specimens of this species were contracted in the posterior trunk and haptor.Euryhaliotrema ferocis most closely resembles E. dontykoleos in the general morphology of the MCO, haptoral bars, and anchors.It differs from E. dontykoleos by possessing hooks with upright acute thumbs (thumbs apparently protruding and knob-like in E. dontykoleos) and by lacking an articulation process in the copulatory complex (present in E. dontykoleos) (see FEHLAUER & BOEGER 2005).Finally, E. dontykoleos parasitizes the gills of a freshwater sciaenid in South America, whereas E. ferocis is marine and occurs on the gills of a lutjanid from the western Pacific Ocean.
This species belongs to the group of congenerics having a cork-screw shaped MCO and a hinge-like thinning in the base of the dorsal anchor.These include E. diplops, E. cognatus and E. ferocis, all parasites of lutjanids from the Indo-Pacific Ocean.It differs from E. diplops and E. cognatus by lacking an articulation process in the copulatory complex and is distinguished from E. ferocis by having approximately three rings in the coiled Although occurring on hosts with distributions throughout the Indian and western Pacific Oceans, E. seyi appears, at present, to be restricted to the western regions of its hosts' respective ranges, including the Persian Gulf and Red Sea.It was not collected from dory snapper and Russell's snapper examined from off the eastern coast of China, Heron Island off Australia, and the environs of New Caledonia.However, comparatively few specimens of both snappers were examined from the various collection sites during the present study, and the possibility exists that all of the species of Euryhaliotrema occurring on these hosts have a more extensive distribution than that suggested by the present survey.Euryhaliotrema spirotubiforum demonstrates a comparatively low level of host specificity, having been recorded from a total of nine species of Lutjanus from the Indo-Pacific Ocean.Respective specimens of E. spirotubiforum from the seven species of Lutjanus, collected and examined for the present study, showed only minimal morphological differences.Euryhaliotrema spirotubiforum most closely resembles E. adelpha, E. paululum and E. youngi, based on the absence of an accessory piece and morphology of the MCO.It differs from E. adelpha by having more robust dorsal and ventral anchors and by the ends of the comparatively robust U-or V-shaped dorsal bar directed laterally (delicate dorsal bar V shaped, with ends directed anterolaterally in E. adelpha).Euryhaliotrema spirotubiforum differs from E. paululum by lacking a posteromedial projection on the dorsal bar and from E. youngi by having a noticeably smaller ring diameter of the coil of the MCO.
The type host of E. spirotubiforum is presumed to be L. vaigensis (now L. fulvus), because this host was listed first in the list of hosts in the original description.However, ZHANG (2001) did not specifically identify the type host of the species or the host of the holotype.Confirmation of the type host for E. spirotubiforum will require identification of the host of the holotype, which was not available for the present study.Etymology: The specific name (a noun) is from Greek (adelpha = sister) and refers to the putative close relationship of this species to E. spirotubiforum and other congeneric species lacking an accessory piece.
Remarks: This species closely resembles E. spirotubiforum, from which it differs by being noticeably smaller and by having a dorsal bar with a posteromedial process.The process is delicate and difficult to observe in some specimens, especially those stained for study of internal organ systems.VIGNON et al. (2009) did not report this species from the common bluestripe snapper, L. kasmira, in the Hawaiian Islands and French Polynesia during their case study on parasite introduction and host management.They identified three dactylogyrid species infecting L. kasmira that are herein included in Euryhaliotrema: E. spirotubiforum, E. chrysotaeniae and a form identified as Haliotrema sp.conf.anguiformis.While E. paululum is recorded from common bluestripe snapper, the similar E. spirotubiforum was not collected from this host during the present study.In view of the primary differentiating feature separating the two species being the difficult to observe and easily missed posteromedial process on the dorsal bar, the ZOOLOGIA 29 (3): 227-276, June, 2012 possibility exists that the form identified by VIGNON et al. (2009) as E. spirotubiforum from Hawaii and French Polynesia may represent E. paululum.Unfortunately, these authors failed to deposit reference material of their helminth species in a museum for species confirmation (J.-L.JUSTINE, personal communication).

Figs 181-187
Description: Body proper fusiform, with nearly parallel sides; greatest width usually in posterior trunk at level of gonads.Tegument smooth.Cephalic region nearly as wide as trunk; cephalic lobes poorly to moderately developed.Four eyespots; members of posterior pair with lenses, slightly larger and closer together than members of anterior pair; accessory chromatic granules ovate, small, few or absent in cephalic region.Pharynx subspherical.Peduncle broad; haptor globose, with rounded bilateral margins.Anchors similar; each with elongate superficial root, knob-like deep root, slightly curved short shaft, elongate point extending slightly past level of tip of superficial root; point with superficial longitudinal grooves; dorsal anchor more delicate than ventral anchor.Bars similar, broadly U shaped.Hook with uniform shank, upright acute thumb; FH loop about shank length.MCO with funnel-shaped base, coiled tubular shaft comprising slightly more than one Type host and locality: Spanish flag snapper, Lutjanus carponotatus (Richardson), Lutjanidae: off Heron Island, Great Barrier Reef, Australia (23°27'S, 151°55'E), 16-23 July 2001.
Etymology: This species is named in honor of Dr. P. C. Young, who conducted extensive surveys and described many new species of Monogenoidea from the Great Barrier Reef in Australia during the 1960s.
Remarks: Euryhaliotrema youngi appears closest to E. spirotubiforum, E. adelpha and E. paululum.It differs from all of these species by having a comparatively wider ring diameter in the shaft of the MCO.

DISCUSSION
Evidence continues to mount indicating that amphiamerican clades (= geminate species pairs) among monogenoids occur in the waters off southern North America.KRITSKY et al. (2009b) suggested such clades among species of Neotetraonchus Bravo-Hollis, 1968, Aristocleidus Mueller, 1936 and Euryhaliotrema (all Dactylogyridae), Rhabdosynochus Mizelle & Blatz, 1941 (Diplectanidae) and Heterobothrium Cerfontaine, 1895 (Diclidophoridae) (see also MENDOZA-FRANCO et al. 2009).These putative clades were thought to have developed through a vicariant coevolutionary model when the Panamanian Isthmus divided historical host and parasite distributions into eastern Pacific and western Atlantic populations about 3.2 mya.Based on morphometrics, additional amphiamerican pairs apparently occur among the Euryhaliotrema species infecting lutjanid hosts.These include the respective specimens currently assigned to E. fastigatum and E. paracanthi from the eastern Pacific Ocean and the Gulf of Mexico and Caribbean Sea and the putative amphiamerican pair represented by the Atlantic species E. longibaculum and the Pacific species E. mehen (see Remarks for the respective species).While confirmation of geminate species pairs of Monogenoidea off North America requires objective phylogenetic analyses, perhaps involving both morphological and molecular data, the occurrence of putative pairs suggests that differentiation of morphological features in the Monogenoidea is a comparatively long process, which in the amphiamerican clades resulted in only slight to insignificant morphological changes developing over the extended period of 3.2 mya.
Isolation of Euryhaliotrema species of the Indo-Pacific regions from those of the western hemisphere is presumably much older than 3.2 mya, and morphological divergence between the species of the two regions is generally greater than that observed within amphiamerican clades.Nonetheless, geminate relationships apparently also exist among the species occurring in the two regions.Based on comparative morphology of haptoral sclerites, for example, E. diplops and E. cryptophallus from the Indo-Pacific Ocean more closely resemble E. fastigatum from the western Atlantic than they do other congenerics occurring in their regional waters.While convergence cannot be discounted, the resemblance of these three species suggests that morphological divergence and speciation within the genus requires an extended period of time that may extend into several millions of years.
While examination of 30 (8 of which were uninfected with Euryhaliotrema spp.) of the 108 extant species of the Lutjanidae resulted in the identification of 27 species of Euryhaliotrema, the small sample sizes and the limited geographic distributions of the hosts that were surveyed suggests that the 33 species of Euryhaliotrema currently known to parasitize lutjanid hosts is far from representing the total diversity of species infecting members of the family worldwide.This is supported, in part, by the finding that the parasite species found to infect examined hosts differed in the various sites surveyed within the respective host's geographic distribution.For example, the mangrove red snapper L. argentimaculatus, Russell's snapper L. russellii, and the dory snapper L. fulviflamma enjoy wide geographic distributions in the western Pacific and Indian Oceans (FROESE & PAULY 2011).Present collections of L. argentimaculatus included sites off eastern China and New Caledonia, while those for L. fulviflamma included Australia, China, New Caledonia and the Red Sea, and for L. russellii, the Persian Gulf and New Caledonia.In none of these localities were identical parasite communities observed, with many of

Figs
Description: Body proper fusiform; greatest width at various levels along trunk.Tegument smooth.Cephalic region broad; cephalic lobes poorly to moderately developed.Four eyespots frequently dissociated; members of posterior pair with lenses, larger and closer together than members of anterior pair; accumulations and single accessory chromatic granules common in cephalic, anterior trunk regions.Pharynx spherical.Peduncle broad; haptor globose.Ventral anchor with moderately long superficial root, short deep root, slightly curved shaft, elongate point extending past level of tip of superficial root; point and shaft with longitudinal superficial grooves.Dorsal anchor similar to ventral anchor except with superficial root uplifted toward dorsal haptoral surface.Ventral and dorsal bars slightly curved rods with minimally enlarged ends; dorsal bar with rectangular enlargement of anteromedial margin.Hook with uniform shank, upright acute thumb; FH loop about shank length.MCO having a bulbous base and a delicately coiled shaft of about two and a half counterclockwise rings.Accessory piece comprising variable sheath along distal shaft of MCO; articulation process connecting accessory piece with base of MCO.Testis ovate; seminal vesicle fusiform; prostatic reservoir lying to right of base of MCO.Germarium subovate to bacilliform; oviduct, ootype, uterus not observed; vaginal pore marginal at

Figs
Figs 91-98Description: Body proper subtriangular, tapered anteriorly from level of testis in posterior trunk; greatest width at level of testis.Tegument smooth.Cephalic region broad; cephalic lobes poorly to moderately developed.Four eyespots; mem-

Figs
Figs 132-137Description: Body proper fusiform, tapering anteriorly from level of testis; greatest width usually in posterior trunk at level of testis.Tegument smooth.Cephalic region broad; cephalic lobes poorly differentiated.Usually single pair of eyespots present; one or both members of anterior pair usually absent, poorly developed (if present); each member of posterior pair with conspicuous lens; accessory chromatic granules small, ovate to subspherical, scattered in cephalic and trunk regions (infrequently absent).Pharynx spherical.Peduncle broad, tapered posteriorly; haptor subhexagonal, with bilateral lobes.Ventral anchor with moderately long superficial root, poorly developed deep root, short shaft, point extending slightly past level of tip of superficial root.Dorsal anchor with elongate superficial root, poorly developed deep root, evenly curved shaft and point; point extending slightly past level of tip of superficial root; base with diagonal hinge, proximal portion of base Kritsky & Yang sp.nov.

Figures
Figures 153-160.Euryhaliotrema seyi sp.nov.from the dory snapper, Lutjanus fulviflamma, from Egypt.153, 154.Copulatory complexes (ventrolateral views).155.Ventral bar.156.Ventral bar (slightly rotated to show the dorsomedial protuberance.157.Dorsal bar.158.Dorsal anchor.159.Hook.160.Ventral anchor.All figures are drawn to the 20 µm scale. Lutjanidae), molecular and other morphological evidence.The molecular evidence used byWU et al. (2006) to transfer the species to Euryhaliotrema was based on the relationships of only three dactylogyrid species (H.spirotubiforum, H. johni and an unidentified species labeled Haliotrema ZHDDb).Later, these authors (2007) again transferred the species, along with Haliotrema kurodai and Haliotrema anguiformis, to Aliatrema, when additional dactylogyrid species were added to their molecular analysis.WU et al. (2007) supported their transfers to Aliatrema by stating that the three related species lacked an accessory piece in their copulatory complex, even though ZHANG's (2001) drawings of H. anguiformis b)  clearly show an accessory piece associated with the MCO in both forms figured for the original description.Because morphological evidence, particularly that of the copulatory complex, no longer supports separating Aliatrema from Euryhaliotrema (see Remarks under the diagnosis of Euryhaliotrema), the combination proposed byWU et al. (2006) is accepted herein.

Table I .
Occurrence of Euryhaliotrema species on the gills of snappers(Lutjanidae).

Table I .
Continued.
Tegument usually smooth, infrequently with transverse ridges or indistinct scales on posterior trunk and peduncle.Cephalic region narrow, with well-developed medial and two bilateral cephalic lobes.Eyespots four, subequal in size; members of respective pairs equidistant; accessory chromatic granules scattered throughout cephalic region.Pharynx subovate.Peduncle tapered posteriorly; haptor subhexagonal, with welldeveloped lateral lobes.Anchors similar; each with moderately developed superficial root, short deep root, slightly arced shaft, elongate point extending past level of tip of superficial root.Ventral bar rod shaped, with wave-like ventral surface imparting a broad W shape; dorsal bar variable, generally broadly V shaped, with variably developed anteromedial knob and posterior expansion or shield-like process.Hook with uniform shank, upright acute thumb; FH loop about shank length.MCO with bulbous base and coiled tubular shaft having about two and a half counterclockwise rings.Accessory piece multibranched, with one branch enclosing and serving as guide for distal portion of shaft of MCO; articulation process absent.Testis elongate ovate; seminal vesicle pyriform; prostatic reservoir small.Germarium subovate; oviduct, ootype not observed; Mehlis' gland well developed, lying on both sides of anterior end of germarium; uterus delicate, ventral, frequently containing developing egg.Vaginal pore marginal on papilla lying within indentation of lateral surface of anterior trunk; vaginal canal short, extending to pyriform pregermarial seminal receptacle.Vitellaria dense, coextensive with gut; transverse vitelline duct at level of or anterior to seminal receptacle.Egg ovate, with proximal filament.

Table II .
Measurements of Euryhaliotrema tubocirrus from four species of Lutjanus and Rhomboplites aurorubens.

Table III .
Measurements of Euryhaliotrema fastigatum from four species of Lutjanus.
Site of infection: Gills.Previous records: No previous records, except that of the original description (LI et al. 2005).
(LI et al. 1995)i)(LI et al. 1995).Lutjanus russellii: South China Sea, China (as Haliotrema johnii) (LI et al. 1995).Lutjanus rhodopterus 1 : Yangjiang, Guangdong Province, China (as Euryhaliotrema johnii) (WU et al. 2006).Sparus macrocephalus (now Acanthopagrus s. schlegelii): Zapo, Yangjiang, Guangdong Province, China (as Haliotrema johni) (LIN & YI 1993); South China Sea, China (as Haliotrema johnii) Kritsky & Justine sp.nov.Body proper fusiform, tapering anteriorly from level of testis; greatest width in posterior trunk at level of testis.Tegument smooth.Cephalic region narrow; cephalic lobes well developed.Two pairs of eyespots; members of posterior pair with lenses, larger and closer together than members of anterior pair; anterior pair occasionally absent or represented by few small ovate granules; few accessory chromatic granules in cephalic, anterior trunk regions.Pharynx spherical.Peduncle broad, tapered posteriorly; haptor subhexagonal to subtrapezoidal, with lateral lobes.Ventral anchor robust, with poorly differentiated deep root, depressed superficial root, slightly curved shaft, point extending slightly past level of tip of superficial root.Dorsal anchor delicate, with knob-like deep root, elongate superficial root, curved shaft, point extending to level of tip of superficial root; base with diagonal hinge (thinning).Dorsal and ventral bars similar, each appearing as broad U or V shapes with slightly enlarged ends.Hook with uniform shank, upright acute thumb; FH loop about shank length.MCO with funnel-shaped base and delicate tubular shaft arranged as a counterclockwise coil of about one and a half rings.Accessory piece comprising variable distal sheath with articulation process extending within rings to base of MCO.Testis elongate ovate; vas deferens, seminal vesicle not observed; single prostatic reservoir large, lying to left of MCO.Germarium bacilliform; Mehlis' gland poorly developed; uterus delicate, midventral.Vaginal pore marginal; vaginal canal short, lightly sclerotized, with distal loop; seminal receptacle pregermarial, pyriform, with neck extending to ventral side of right intestinal cecum to unite with vaginal canal.Vitellaria dense; bilateral vitelline ducts extending from lateral bands toward midline anterior to seminal receptacle, joining to form common vitelline duct.Egg not observed. Description: Kritsky & Justine sp.nov.Accessory chromatic granules small, ovate, scattered in cephalic and anterior trunk regions.Pharynx spherical.Peduncle broad; haptor subhexagonal, with rounded bilateral lobes.Ventral anchor with moderately long superficial root, short broadly truncate deep root, arcing shaft, point extending slightly past level of tip of superficial root.Dorsal anchor delicate, with elongate superficial and deep roots, slightly curved shaft and elongate point extending past level of tip of superficial root.Ventral bar broadly V shaped, with spatulate ends; dorsal bar a slender arcing rod.Hook with uniform shank, upright acute thumb; FH loop about shank length.MCO lightly sclerotized, with bulbous base, short tubular coiled shaft of less than one counterclockwise ring.Accessory piece variable, poorly developed, lying along distal shaft of MCO; articulation process absent.Testis elongate ovate; proximal vas deferens not observed; seminal vesicle lying to left of body midline posterior to MCO; prostatic reservoir juxtaposed to seminal vesicle to right of body midline.Germarium bacilliform to subovate; oviduct, ootype, uterus not observed; Mehlis' gland well developed.Vaginal pore dextromarginal; vaginal canal a narrow duct; seminal receptacle immediately anterior to germarium.Vitellaria dense; bilateral vitelline ducts confluent anterior to seminal receptacle.Egg not observed.
Kritsky & Justine sp.nov., elongate slightly depressed superficial root, slightly curved shaft, point extending past level of tip of superficial root; anchor shaft and point with superficial longitudinal grooves.Ventral bar a wavy rod with knob-like ends directed posterolaterally.Dorsal bar delicate, V shaped.Hook with uniform shank, upright acute thumb; FH loop about shank length.MCO with funnel-shaped base and loosely coiled shaft having slightly more than one counterclockwise ring.Accessory piece absent.Testis ovate; vas deferens, seminal vesicle, prostatic reservoir not observed.Germarium subovate to bacilliform; Mehlis' gland poorly developed; uterus, seminal receptacle not observed.Vaginal pore submarginal, inconspicuous; vaginal canal short, non-sclerotized.Vitellaria dense; bilateral vitelline ducts extending from lateral bands toward midline anterior to Mehlis' gland.Egg not observed. root wide.Remarks: Euryhaliotrema adelpha most closely resembles E. spirotubiforum in the general morphology of the MCO and haptoral anchors.It differs from this species by having a more elongate and delicate shaft of the ventral anchor (compare Figs 166, 174) and by having a V-shaped dorsal bar with ends directed anterolaterally rather than laterally (compare Figs 163, 171).paululum Kritsky & Justine sp.nov.Body proper fusiform; greatest width in posterior trunk at level of testis.Tegument smooth.Cephalic region broad; cephalic lobes poorly to moderately developed.Four eyespots; members of posterior pair with lenses, larger, slightly closer together than members of anterior pair; accessory chromatic granules subovate to irregular, uncommon in cephalic region.Pharynx spherical.Peduncle broad; haptor subhexagonal.Anchors similar; each with elongate superficial root, knob-like deep root, curved short shaft, elongate point extending slightly past level of tip of superficial root; anchor shafts and points with longitudinal superficial grooves; dorsal anchor more delicate than ventral anchor.Bars similar, broadly U or V shaped; dorsal bar with short posteromedial process.Hook with uniform shank, upright acute thumb; FH loop about shank length.MCO with funnel-shaped base, loosely coiled tubular shaft having slightly more than one counterclockwise ring.Accessory piece absent.Testis ovate; seminal vesicle pyriform, lying posterior to base of MCO; prostatic reservoir comparatively large, lying to left of shaft of MCO.Germarium subspherical to bacilliform, ventrally overlapping anterior end of testis; oviduct, ootype, uterus not observed.Vaginal pore marginal, inconspicuous; vaginal canal unsclerotized, straight, directed diagonally and posteriorly to unite with medial subspherical seminal receptacle.Vitellaria dense; transverse vitelline duct anterior to seminal receptacle.Egg not observed.Type host and locality: Common bluestripe snapper, Lutjanus kasmira (Forsskål), Lutjanidae: External slope of coral barrier facing the wreck Ever Prosperity, off Nouméa, New Caledonia (22°27.588'S,166°21.920'E),22 August 2006.Site of infection: Gills.Specimens studied: Holotype, MNHN JNC1923K1; 12 paratypes, MNHN JNC1923K2-K5, USNPC 105558. Description: