New records of caridean shrimps ( Decapoda : Caridea ) from shallow water along the northern Yucatan peninsula coasts of México

The northern coast of the Mexican state of Yucatán has only been cursorily sampled in the past, with most of this effort concentrated on the largest coral reef in the Gulf of México, Arrecife Alacranes. The present study reports on recent collections (June 2008 September 2013) of caridean shrimp in Yucatán, including Arrecife Alacranes and other reefs, as well as coastal lagoons and beaches. Additionally, a number of species are reported based on older, unidentified museum material. Six species represent new records for the Gulf of México [Janicea antiguensis (Chace, 1972), Gnathophyllum modestum Hay, 1917, Lysmata jundalini Rhyne, Calado and dos Santos, 2012, Periclimenes sandyi De Grave, 2009, Rapipontonia platalea (Holthuis, 1951a), Typton tortugae, McClendon, 1911], and 11 species are confirmed new records for México [Lysmata ankeri Rhyne and Lin, 2006, L. pederseni Rhyne and Lin, 2006, L. rafa Rhyne and Anker, 2007, Ascidonia miserabilis (Holthuis, 1951b), A. quasipusilla (Chace, 1972), Neopontonides chacei Heard, 1986, Periclimenaeus maxillulidens (Schmitt, 1936), P. pearsei (Schmitt, 1932), P. schmitti Holthuis, 1951b, Typton prionurus Holthuis, 1951b, Processa manningi De Grave and Felder, 2012], adding up to a total of 17 newly reported species for the East coast of México. Further, the colour pattern of several species is documented for the first time.


INTRODUCTION
The known fauna of caridean shrimps from the Gulf of México currently comprises 252 species belonging to 73 genera and 22 families (Anker, 2010(Anker, , 2012;;Anker and De Grave, 2010;Felder et al., 2009).Of these, only 103 shallow water species have been reported so far from the eastern coasts of México (Álvarez et al., 1999;Barba et al., 2005;Barba et al., 2010;Escobar-Briones and Jiménez-Guadarrama, 2010;Escobar-Briones and Villalobos-Hiriart, 2003;Felder et al., 2009;García-Madrigal et 2005b;Wicksten, 2005c).Although the knowledge of caridean species in the Mexican part of the Gulf of México is quite considerable, it does not appear exhaustive compared to the effort in the United States region of the Gulf, as the herein included additional records demonstrate.
In order to contribute to the knowledge of carideans along the Mexican coastline of the Gulf of México, a number of sampling campaigns have been carried out since 2008 along the Yucatán peninsula by the BioDiversidad Marina de Yucatán team (BDMY) at Unidad Multidisciplinaria de Docencia e Investigación de Sisal (UMDI-Sisal), concentrating on the largest offshore reef system of the Gulf of Mexico (Arrecife Alacranes) and two of the Sisal banks reef system (Zarco-Perelló et al., 2013) (Serpientes and Madagascar reefs), northeast off the Yucatán peninsula, but supplemented by fieldwork in the marshes, estuaries, and coastal wetlands of north-western Yucatán peninsula, from Celestún to Ría Lagartos (Fig. 1).Some points along the Caribbean coast of México were also sampled (Fig. 1).

MATERIAL AND METHODS
Sampling was conducted in a focused manner, targeting potentially shrimp rich habitats, such as coral reefs, seagrass beds, tidal flats, coral rubble, and focusing on known host species such as sponges and echinoderms.In general manual collecting was carried out, both by SCUBA and snorkelling as well as by push-net over suitable habitat.Sampling effort was concentrated in the Yucatán Peninsula region (Fig. 1).The studied material is deposited in the Colección de Crustáceos, UMDI-Sisal (YUC-CC); the Colección Nacional de Crustáceos, UNAM, Ciudad de México (CNCR) and in the Zoological Collection of the Oxford University Museum of Natural History, Oxford, United Kingdom (OUMNH-ZC).Abbreviations used are "pocl" for postorbital carapace length, in mm, and "fcn" for field collection number (prefix DSM for the first author, NS for third author).Species reported without fcn numbers are based on reidentifications of material by the first author in the CNCR collection.Species were considered to be new records for the Gulf of México, if within the geographical boundaries outlined for the Gulf by Felder et al. (2009) and not previously reported.The classification adopted here follows De Grave and Fransen (2011).
Distribution: Janicea antiguensis has been reported previously from Bermuda, the Bahamas, and Antigua (Kensley, 1988), as well as Fernando de Noronha (Ramos-Porto  and Coelho, 1991), Pernambuco and Espírito Santo, Brazil (Giraldes et al., 2012), in the western Atlantic.It is also known from the Cape Verde Islands, São Tomé and the Canary Islands in the eastern Atlantic (d'Udekem d'Acoz, 2000;Wirtz, 2004).Within Mexican waters, the species has been reported from a single anchialine cave system, Cueva Quebrada in Cozumel (Kensley, 1988).Some of Kensley's (1988) material was re-examined by d'Udekem d' Acoz (2000) who erroneously placed this locality inside the Gulf of México.The species has also been recorded from 350 m deep on the Banco Chinchorro escarpment in Quintana Roo (Escobar-Briones and Villalobos-Hiriart, 2003).Although Giraldes et al. (2012) state that the species also occurs in Yucatán, no earlier records substantiating this could be traced.Thus, the present specimens constitute the first confirmed record of the species for the Gulf of México coast of México and by extension the entire Gulf.
Family Gnathophyllidae Dana, 1852 Gnathophyllum modestum Hay, 1917 (Fig. 2B) Remarks: The present specimen only has five dorsal teeth and one minute distal ventral tooth, corresponding to Manning's (1963) description.According to Manning (1963), the color pattern of living material is a diagnostic feature in this genus and the present specimen matches the colour notes in Manning (1963) (Fig. 2B) with a deep brown background carapace and abdomen, many scattered small yellow spots throughout the somites and a few larger orange spots towards the frontal part of the body.This specimen has an anterior series of 2 antero-dorso-lateral orange spots on each side of the carapace and a series of 3 larger orange spots ventrally, on the base of each first maxilliped.
Remarks: This material close corresponds to the type description (Rhyne and Lin, 2006), with the more than 34 carpal segments of the second pereiopod and the rostrum not over-reaching the antennular peduncle being characteristic for the species.
Distribution: The species appears to be widespread, ranging from Florida southwards to Brazil (Rhyne and Lin, 2006;Wirtz et al., 2009).Although the species was known to occur in the northern Gulf of México (Rhyne and Lin, 2006), it had not been previously recorded in Mexican waters.
Remarks: The majority of the material corresponds close to the type description (Rhyne et al., 2012) in having 22-24 fused segment on the lateral antennular flagellum, as well as three accessory spines on the dactyl of the ambulatory pereiopods.However, two ovigerous females harboured four accessory spines on the dactyl on all ambulatory pereiopods, but with 22 and 24 fused antennular segments respectively.The colour pattern of the present material clearly shows the blue spot on the coxa of the fourth pereiopod, considered characteristic for the species (Rhyne et al., 2012).
Distribution: The species was previously only known from Cayo Enrique, La Parguera, Puerto Rico (Rhyne et al., 2012), but is known to be more widespread in the southern Caribbean (De Grave and Anker, pers.obs.).The present specimens extends its distribution considerably north-westwards to Arrecife Alacranes and constitute the first record for the Gulf of México, as well as México.
Remarks: The material corresponds closely to the type description (Rhyne and Lin, 2006) and presents no special features.All material collected during the present study from Arrecifes Madagascar and Alacranes was collected from inside the osculum or on the outside of Callyspongia vaginalis (Lamarck, 1814), which is one of the main host species (Rhyne and Lin, 2006).The colour pattern of the present material closely matches the type material (Rhyne and Lin, 2006).
Distribution: The species ranges from Florida southwards to Venezuela (Rhyne and Lin, 2006).Although widespread including the northern Gulf of México, the present specimens constitute the first record of the species from Mexican waters.
Remarks: The single specimen is typical for the species with a long, upwardly curved rostrum with seven dorsal and eight ventral teeth, elongated third maxillipeds as well as elongated ambulatory pereiopods (Rhyne and Anker, 2007).
Distribution: The species was previously only known from Biscayne Bay and Key West Lakes, Florida (Rhyne and Anker, 2007).The present specimen extends its distribution considerably southwards and constitutes the first record for México.
Distribution: The species is widespread, ranging from the northern part of the Gulf of México (Wicksten, 2005a), Caribbean (Fransen, 2002(Fransen, , 2006;;Holthuis, 1951b), to Atol das Rocas (Brazil) (Pachelle et al., 2012).Although recorded in the northern part of the Gulf of México, the present specimen represents the first record of the genus in Mexican waters.

Remarks:
The present specimen corresponds closely to the re-description of the species (Fransen, 2002), although it is the smallest ovigerous female known to date.The specimen has 15 large eggs (0.4-0.5 mm) (Fig. 2E), contrasting to the Mauritanian material examined by Fransen (2002) which had 100-200 eggs (0.6-0.7 mm).The number of eggs of the female holotype from Antigua (Chace, 1972) is not known, which is the only other known ovigerous specimen from the West Atlantic.This difference between West and East Atlantic specimens assigned to this species warrants closer scrutiny.
Distribution: The species was previously recorded from Antigua and Martinique (Chace, 1972) as well as Guadeloupe (Fransen, 2002) in the western Atlantic, and Mauritania in the eastern Atlantic (Fransen, 2002).The present specimen constitutes the first record of the species for the Gulf of México, and thus by extension México.Heard, 1986 (Fig. 2F)
Remarks: The present specimens correspond closely to the type description (Heard, 1986) in harbouring equal and similar second pereiopods, slender ambulatory pereiopods with a poorly developed or absent tubercle on the distal flexor margin of the merus.The colour pattern (Fig. 2F) shows the species to be largely transparent, with some scattered red dots on the carapace and the lateral sides of the pleura.
Distribution: Previously reported from Marigot Bay, St. Lucia Island, Falmouth, Antigua, Carrie Bow Cay, Belize, Looe Key and Bahia Honda Key, Florida (Heard, 1986), Honduras associated with P. americana (De Grave, 2009) and the northern Gulf of México associated with Leptogorgia spp.(Wicksten and Cox, 2011).The present records from Arrecifes Alacranes and Madagascar constitute the first record for Mexican waters.
Remarks: The material is damaged, with one specimen missing the telson, both second pereiopods as well as the left third and fourth pereiopod, whilst the other specimen lacks the major second pereiopod as well as both fifth pereiopods.The rostrum in both specimens is short, barely reaching the distal margin of the eye, harbouring one and two dorsal teeth, respectively.The short, poorly armed rostrum, combined with a simple dactylus on the ambulatory pereiopods as well as a short distolateral tooth on the scaphocerite and the lack of the anterolateral tooth on the basal segment of the antennular peduncle, confidently secures the identity of these specimens.The colour pattern (Fig. 2G) shows the species to be largely transparent, but with a dense covering of small, white dots all over the body, pereiopods, uropods, telson and uropods.
Distribution: The species was previously only known from a single specimen from Bonaire, with the habitat described as sandy debris behind the reef (Schmitt, 1936) and a further non-ovigerous female from off Cape San Blas, Florida, collected on coarse grey sand, broken shells, gravel, sand, coral (Holthuis, 1951b).As the present specimens were collected inside a dead conch shell, it remains unknown whether the species associates with sponges or ascidians.The present specimens constitute the first record of the species for México.
Remarks: The specimens corresponds closely to the re-description of the species in Holthuis (1951b), with the globose carapace, the rostral dentition (4/0) as well as the shape of the minor second pereiopod being characteristic of the species.The colour pattern of the species is not known (Fig. 2H).
Distribution: The species was previously only known from the Dry Tortugas, Florida (Holthuis, 1951b) from Spongia officinalis Linnaeus 1758 andMaranhão, Brazil (Ramos-Porto andCoelho, 1990), between 46-52 m depth.The present specimens present the first record of the species for México, a different host record, as well as being much shallower than previously recorded.Holthuis, 1951b (Fig. 2I)
Distribution: The species was previously known from Bogue Sound, North Carolina and the Dry Tortugas, Florida (Chace, 1972;Williams, 1965).Garcia-Madrigal et al. (2002) also recorded the species from an unspecified location in Quintana Roo in a regional checklist.The present record is the first for the southern Gulf of México.
Remarks: The specimens correspond closely to the type description (De Grave, 2009), harbouring asymmetrical second pereiopods, with two teeth on the cutting edges of the major chelae.The present records confirm that the host species is Callyspongia vaginalis, with all specimens collected from the osculum.In general, females are larger than males, eggs in ovigerous females measure 0.4-0.5 mm diameter.The colour pattern of the species is now illustrated for the first time (Fig. 2K), and the species is largely transparent, but with a dense scattering of red dots on the carapace and the ventral side of the pleura, as well as the second pereiopods.
Distribution: Previously only known from the type locality, Crawl Cay, Bocas del Toro, Panama (De Grave, 2009).The present record constitutes a significant northwardly extension, as well as the first record for the Gulf of México and by extension, Mexican waters.
Remarks: The present specimens correspond closely to the descriptions in Holthuis (1951a) and Marin (2009) in their general features but harbour fewer dorsal rostral teeth (6 in the male and 5 in the female, respectively), corresponding to some of the specimens illustrated by Marin (2009).
Distribution: The species has been recorded from Senegal, Cape Verde, São Tomé and off Guinea in the eastern Atlantic (Holthuis, 1951a;Marin, 2009;Wirtz and d'Udekem d'Acoz, 2001;Wirtz and De Grave, 2010).Within the western Atlantic, the species was previously only known from Tobago (Hale and De Grave, 2007), the present specimens thus represent the first record of the species for México and the Gulf of México.In contrast to the other species in the genus, which only associate with hydroids (Marin, 2009), R. platalea has been found on hydroids (Hale and De Grave, 2007), black coral (Wirtz and d'Udekem d'Acoz, 2001) and gorgonians (Wirtz and d'Udekem d'Acoz, 2001;Wirtz and De Grave, 2010), although the host of the current specimens is not known.
Remarks: The specimen corresponds closely to the re-description of the type material in Holthuis (1951b) and presents no noteworthy features.The specimen has a pocl of 3.7 mm, harbouring 15-20 eggs with 0.4-0.6 mm in diameter.The colour pattern of the species is now illustrated for the first time and shown to be largely transparent, with an orange-red hue (Fig. 2L).
Distribution: The species was previously only known with certainty from the type material from the Dry Tortugas, Florida (Holthuis, 1951b), although a questionable record exists from off Pará, Brazil (Bullis and Thompson, 1965).The present record is the first for México.Remarks: The specimens correspond closely to the re-description of the species by Holthuis (1951b) and present no noteworthy features.
Distribution: The species is known from Bermuda, the Dry Tortugas, Virgin Islands, the Brazilian states of Pará and Maranhão as well as Fernando de Noronha (Vieira et al., 2012).Additionally, the species has been recorded in the Gulf of California (East Pacific) by Wicksten (1983).The present specimen represents the first record for the Gulf of México.
Remarks: All specimens are damaged with many pereiopods missing, although the ovigerous female has both second pereiopods, which are strongly asymmetrical.The material is assigned to P. manningi on account of the unarmed stylocerite, the presence of a small posteromedian tooth on the lobe on the sixth pleonite, the presence of an anteromedial row of setae on the telson and the strongly developed antennal spine.In comparison with the type material (De Grave and Felder, 2012), the longitudinal, lateral row of setae on the telson is poorly developed in two specimens, although this could be due to abrasion during sampling.The colour pattern (Fig. 2M) of the present specimens matches the type material in De Grave and Felder (2012).The specimens were obtained by yabby pump on very shallow, muddy and fine shell bottoms in burrows, likely made by callianassids.Although no callianassids were collected in the same burrows as P. manningi, Neocallichirus grandimana (Gibbes, 1850), the host species in Belize (De Grave and Felder, 2012), was common in the same habitat.

Distribution:
The species was previously only known from Belize (De Grave and Felder, 2012), the present record extends its distribution into the south Caribbean coast of México.

DISCUSSION
The present contribution details six new records for the Gulf of México, as well as 11 new records for Mexican waters.This raises the known caridean shrimp fauna of the Gulf of México to 258 species, of which 114 are currently known from shallow, coastal waters in México.As an estimated 35-40 caridean species in the Gulf of México are exclusively known from continental slopes and deeper, it thus appears that the known shallow water Mexican fauna approximates only half the total caridean biodiversity in the Gulf.Certain areas along the Mexican part of the Gulf appear well sampled, for instance Tamaulipas and Campeche, due to local shrimp fisheries and oil industry, however these are primarily sedimentary environments, which hold relatively little caridean biodiversity compared to reefs.The more complex inshore and offshore reef systems and associated environments in Veracruz and Yucatán remain relatively poorly sampled to date, and are likely to hold considerably higher numbers of species, as the current records amply demonstrate.
Despite the perceived lower sampling effort in reefal environments along the southern coastline of the Gulf of México, an examination of available species lists, does show that both Veracruz and Yucatán, already have a rich caridean biodiversity, with 69 and 104 species known, respectively.In contrast, the known species fauna of Campeche is lower at 56 species.Of all the Mexican states along the Gulf of México coast, Tamaulipas and Tabasco appear to hold lower diversity, at 10 and 3 species respectively.As already discussed, this is likely linked to sedimentary environments predominating in those area.Although the small number of species known from Tabasco does suggest a lack of sampling effort.
The total number of species known from Yucatán (104) compares favourably with the 83 known species from Quintana Roo along the Caribbean coast, which historically has seen more sampling effort.To further document the expected rich biodiversity of these areas, concerted sampling as well as deploying novel collecting techniques, such as yabby pumping, bait and light trapping would be beneficial.

Figure 1 .
Figure 1.Location of the collecting sites at Yucatan peninsula, México.
. Within Mexican waters, this is the first record of the species in Veracruz and north Madagascar Reef in Yucatan.