Crenicichla chicha , a new species of pike cichlid ( Teleostei : Cichlidae ) from the rio Papagaio , upper rio Tapajós basin , Mato Grosso , Brazil

Crenicichla chicha, new species, occurs in clear, fast-running waters with rocky substrates in the rio Papagaio and tributaries. It is distinguished from all other Crenicichla species by the combination of two character states: infraorbitals 3 and 4 coossified (vs. separated) and 66-75 scales in the row immediately above to that containing the lower lateral line (E1 row scales). Crenicichla chicha shares a smooth preopercular margin, co-ossification of infraorbitals 3 and 4, and some color features with C. hemera from the adjacent rio Aripuanã drainage, rio Madeira basin. It differs from Crenicichla hemera in more E1 scales (6675 vs. 58-65) and presence of a conspicuous black narrow stripe running from infraorbital 3 obliquely caudoventrad toward the preopercular margin vs. a rounded and faint suborbital marking present on infraorbitals 3-4. Examination of the type series and additional material from the rio Aripuanã confirms that Crenicichla guentheri Ploeg, 1991 is a junior subjective synonym of C. hemera Kullander, 1990.


Introduction
Crenicichla Heckel is considered to be the most species rich genus of South American cichlids, comprising 84 valid species (Kullander, 2003;Kullander & Lucena, 2006;Casciotta et al., 2006;Lucena, 2007;Casciotta & Almirón, 2008;Montaña et al., 2008;Kullander, 2009;Piálek et al., 2010;Casciotta et al., 2010).These fishes are popularly known in Brazil as "joaninhas", "peixes-sabão" and "jacundás" and are found over most river drainages of tropical to temperate cis-Andean South America (Kullander & Lucena, 2006).Earlier revisions of the genus were made by Pellegrin (1904) and Regan (1905Regan ( , 1913)).The relatively recent revision of Crenicichla by Ploeg (1991), though an important contribution, is unfortunately plagued with several shortcomings and certainly cannot be considered a definitive monograph of the systematics of the genus.More recent taxonomic studies of the genus have been developed within a regional scope, restricted to river drainages or geographic units (e.g.Lucena & Kullander, 1992;Kullander & Lucena, 2006).The current knowledge of the phylogenetic relationships among Crenicichla and the related genus Teleocichla was recently summarized by Kullander et al. (2009).Overall, it can be concluded that there is still much research to be accomplished before a comprehensive view of the phylogenetic relationships within this large and morphologically diverse genus is reached.
Recent collecting activities in the rio Juruena, a major headwater of the rio Tapajós in the State of Mato Grosso, Brazil, revealed a distinctive, undescribed species of Crenicichla similar to C. hemera Kullander.The purpose of the present paper is primarily to describe this new species.Based on the comparative examination of extensive series of its putative close relative C. hemera, we also take this opportunity to provide additional diagnostic data and describe variation in that species.We also address the status of C. guentheri Ploeg, placed in the synonymy of C. hemera by Kullander (1997), based on the type series and a much larger material now available from the Aripuanã drainage.

Material and Methods
Specimens lengths are given as standard length (SL), measured from the tip of the upper jaw to the middle of the base of caudal fin.Measurements and counts were taken as described by Kullander (1986) and presented as percentages of SL.Counts from the holotype indicated by an asterisk (*).Scales in a longitudinal row (E1 scales row) are counted in the row immediately dorsal to that containing the lower lateral line.Color marking terminology follows Kullander (1986) and Kullander & Lucena (2006).Vertebral counts and osteological notes on the new species were based on one specimen, 70.2 mm of SL (MZUSP 93683), cleared and stained following the method of Taylor & van Dyke (1985).Vertebral counts include the last half-centrum.The lower pharyngeal tooth plate is measured as described by Barel et al. (1977).Illustrations of the pharyngeal tooth plate and the infraorbitals were based on the cleared and stained specimen, photographed under a stereomicroscope and further manipulated with image editor software.
Institutional abreviations: Asociación Ictiológica, La Plata, Argentina (AI); Instituto Nacional de Pesquisas da Amazônia, Manaus, Brazil The co-ossification of the infraorbitals 3 and 4 is an uncommon character state shared only with Crenicichla hemera.These species also share other uncommon characteristics, as the smooth preopercle and absence of microbranchiospines, but the new species differs from C. hemera in the presence of 66-75 scales in E1 row (vs. 58-65), and by having a conspicuous narrow suborbital stripe running from infraorbital 3 obliquely caudoventrad toward preopercular margin (vs.suborbital marking rounded, situated on infraorbitals 3-4).
Description.Largest male 137.7 mm SL, largest female 97.2 mm SL.Morphometric data in Table 1.
Head slightly deeper than wide.Snout moderately long, rounded when viewed from above, bluntly pointed in lateral view.Lower jaw slightly prognathous, its articulation below middle of orbit; ascending premaxillary processes reaching to about 1/3 of orbit diameter; maxilla almost reaching to vertical from anterior margin of orbit.Lips thick and wide, lower lip folds separate anteriorly; folds of upper lip not continuous but cutting into a symphyseal thickening.Postlabial skin fold margin truncate.Orbit supralateral, not visible from below, almost entirely in anterior half of head.Interorbital area flat, narrower than mouth.Nostril dorsolateral, about halfway between orbit and margin of postlabial skin fold, with low tubular margin but no anterior marginal membranaceous skin flap.No preopercular or other serrations on head bones, neither on supracleithrum.Lateralis pores on head simple or with two small openings, easily visible.Infraorbitals 3 and 4 co-ossified, with a median opening (Fig. 2).
Flank scales weakly ctenoid.All scales cycloid on head, on dorsum above anterior half of upper lateral line, along dorsal-fin base, on chest, and on belly below line from lower edge of pectoral-fin base to anal-fin origin.Predorsal scales small, embedded in skin, extending forward to transverse frontal lateralis canal; prepelvic scales slightly smaller than predorsal ones.Cheek completely scaled, about 6-9 horizontal scale rows below orbit, superficially embedded in skin.Interopercle naked or with a patch of 1-3 scales posteriorly, embedded in skin.
All teeth pointed, slightly recurved, teeth in outer row fixed,  Color in alcohol.Underside of head, chest, abdomen below level of pectoral-fin base and narrow zone along anal-fin base and ventral edge of caudal peduncle tan.Cheek light brown, preopercle and gill cover light grey.Snout dorsally and interorbital area dark grey.Sides and nape brownish to grey, scales almost uniformly pigmented.Lateral-line scales uniformly pigmented with same color as adjacent scales.
Preorbital stripe black and conspicuous, running from tip of lower jaw, continuing backwards onto upper lip, running below level of nostrils to orbit.Postorbital stripe appears as continuation of preorbital stripe, running behind orbit to opercular angle and onto supracleithrum with a ventral extension onto medial side of pectoral axilla.
Dark brownish, almost black narrow stripe parallels postorbital stripe, running just behind upper margin of orbit to extrascapular area; dark brownish double-marking on area corresponding to supraoccipital crest; both markings more or less masked by dark nape coloration in larger specimens.Narrow uniformly pigmented suborbital stripe running from infraorbital 3 obliquely caudoventrad toward preopercular margin.
Spots absent from pectoral-fin base.Humeral blotch absent.Dark midlateral stripe, 2-3 scales deep, continuous from supracleithrum to caudal peduncle.Seven to nine wide, relatively faded dark vertical bars, anteriormost at nape, 5-7 bars situated below dorsal fin base, last bar at caudal peduncle.Vertical bars fuse with midlateral stripe, forming a distinct midlateral row of continuous blotches, giving an overall marbled color pattern.Largest specimen examined (MZUSP 93510, 137.7 mm SL) with dark bars considerably more conspicuous than midlateral stripe, forming an overall barred pattern.A faint, often interrupted dark lateral band along the abdominal side present in some specimens.
Dorsal fin smoky with irregular narrow brown markings on spinous portion and up to five rows of small dots on soft portion; continuation of vertical bar pigmentation on dorsal fin base.In larger males, dorsal fin almost uniformly pigmented, with dark margin.In MZUSP 107043 (76.8 mm SL), dorsal fin without dots or dark margin but with remaining vertical bars pigmentation on fin base.
Anal fin greyish, gradually darker to lower margin.Pectoral fin hyaline, slightly dusky near base.Pelvic fin hyaline, slightly dusky on spine and anterior rays.Dark midlateral stripe continuing into middle caudal-fin rays as a lanceolate dark blotch extending across 3/4 of caudal fin length.Subdistal dark pigmentation contouring caudal fin, marginal area clear.Small scattered dark dots on dorsal and ventral caudal fin portions on most specimens.Ocellated caudal blotch black, rounded, ringed with light pigment, situated on the dorsal lobe, between rays V1 and D3.
Young specimen.Dorsal portion of head and body yellowish green, ventral portion of head and abdominal region pale.Preorbital, postorbital and lateral band dark grey, running beyond caudal peduncle.Suborbital stripe maroon.Vertical Adult male.Head, nape, pectoral-fin basis, and dorsum to about the fifth dorsal spine lemon green.Sides of body bluish grey; preorbital, postorbital, lateral band, and vertical bars of flanks dark grey, less evident than in the young specimen.Irregular, narrow, wavy orange vertical stripes formed by pigmentation concentrated on scale margins distributed across flanks and caudal peduncle, relatively small anteriorly, longer and densely concentrated towards caudal peduncle, where they present a net arrangement.Pectoral fin lemon green.Pelvic spine and three anterior rays yellowish, remaining pelvic fin rays hyaline.Dorsal fin rays red, interradial membranes reddish.Distal portion of anal fin yellowish, basal portion bluish grey, with rows of red spots at basis.Caudal fin red, except for lanceolate dark grey stripe on middle caudal fin rays.
Distribution.Crenicichla chicha is known from the rio Papagaio and tributaries, itself a tributary of the rio Juruena, a major headwater of the rio Tapajós in the state of Mato Grosso, Brazil (Fig. 6).The new species was collected both above and below the Cachoeira do Utiariti, a major (about 90 meters high) waterfall in the rio Papagaio.
Etymology.The new species is named Crenicichla chicha as homage to the Paresi (or Halíti), one of the indigenous groups originally living in the Mato Grosso plateau in the region of the upper rio Juruena basin.The epithet refers to "chicha" festivities of these people, in what they meet to drink "olóniti", a beverage made with roasted tapioca (cassava starch) of mandioca brava (bitter cassava), dance, and sing their myths.Nowadays, these celebrations occur mainly when they conclude rites of individual passage -nomination of children and pubertal girls, or within a timetable ritual, such the first harvest time of a culture of cassava.Treated as a noun in apposition.
Ecological notes.The water of the rio Papagaio is transparent and runs over a predominantly rocky bed, with swift current, and numerous rapids.One of the authors (FCTL) observed (during snorkeling) specimens of Crenicichla chicha in the rio Papagaio mainly in backwaters, or behind large boulders where water current was relatively slack.Crenicichla chicha was also observed and collected in smaller tributaries, such as the ribeirão Vinte e Cinco de Maio (which has slightly turbid waters and a predominantly sandy/muddy bottom).Like other species of Crenicichla, C. chicha is inquisitive, approaching divers, and easily collected by hand net during snorkeling.Crenicichla chicha was the only Crenicichla species occurring above the Cachoeira do Utiariti, but below this major waterfall it occurs syntopically with an undescribed species belonging to the C. saxatilis species group.

Discussion
As it could be expected from a highly speciose genus, there is a relatively broad morphological variation among species of  Crenicichla, a subject which has elicited a fair amount of discussion in the literature during the last 30 years (Kullander, 1981;1982, 1986, 1990a, b, 1991, 1997;Ploeg, 1991;Lucena & Kullander, 1992;Kullander & Lucena, 2006).More recently, phylogenetic molecular analyses examining the relationships of sub-sets of Crenicichla, with emphasis on species from southeastern South America, have been published (Kullander et al., 2009;Piálek et al, 2010).Kullander et al. (2009) provided the most comprehensive and updated discussion on putative monophyletic units within Crenicichla.
Some of the diagnostic character features of Crenicichla chicha, such as the smooth preopercle, the fusion between infraorbitals 3 and 4, and the absence of microbranchiospines, do not allow a prompt allocation of C. chicha in any of the currently recognized groups within the genus.
The smooth preopercle is an uncommon feature among species of Crenicichla, which typically have a denticulate preopercular margin.This character state is shared with species of C. missioneira group (sensu Lucena & Kullander, 1992;Lucena, 2007;Kullander et al., 2010) Most African and Asian cichlids and basal Neotropical cichlids possess a series of five separate post-lacrimal infraorbital ossicles (infraorbitals 2-6).This condition is also present in the majority of species of Crenicichla, whereas in the closely related genus Teleocichla and in the majority of Neotropical cichlids and the African Tylochromis, infraorbitals 3 and four are co-ossified, as in C. hemera and C. chicha.In a few taxa infraorbitals 2, 4, and 5 are co-ossified, and in diminutive species one or more infraorbitals are lost (Kullander, 1998).Crenicichla chicha and C. hemera do not share any of the several autapomorphic character states identified in Teleocichla and which are apparently correlated with the benthic, rheophilic biology of species of that genus (Kullander, 1988).The overall similarity in morphology and colour pattern and the geographical proximity of C. hemera and C. chicha supports the interpretation of the shared presence of co-ossified infraorbitals 3-4 as a indicator of close phylogenetic relationship, unique within Crenicichla, and independently derived versus the same condition in Teleocichla, and other cichlid genera.
In most cichlids, and also most species of Crenicichla microbranchiospines are present on the 2 nd through 4 th gill arches.Microbranchiospines are frequently absent in cichlid species of small adult size, including Teleocichla and the small species of the C. wallacii group (Kullander, 1988(Kullander, , 1990a)).
Crenicichla chicha is more similar to C. hemera than to any other species in the genus.They share the co-ossification of the infraorbitals 3 and 4, a smooth preopercle, and the  absence of microbranchiospines.They also show some similarities in head and flank coloration: conspicuous preorbital and postorbital stripes, and the presence of a lateral band at least in juveniles.Both lack small scattered dots and horizontal stripes on flanks.Kullander (1990b) highlighted as a unique color feature of C. hemera the presence of a second dark lateral band along the abdominal side, fragmented and fainter than the superior one.This stripe can be seen also in some of the examined specimens of C. chicha and in some specimens of the type series of C. guentheri, as a broad expansion of the ventral portion of the vertical bars on flanks, but in the majority of the material it is inconspicuous or absent.
Crenicichla hemera was described based on small specimens (45.0-96.7 mm SL), juveniles and subadults, from a headstream of the rio Cinta Larga, rio Aripuanã drainage (Kullander, 1990b).Kullander (1990b) suggested that the species possibly could grow to a larger size and that adult males might present a distinct color pattern.Ploeg (1991) described C. guentheri as a species belonging to the C. saxatilis species group species, and diagnosed it by having usually exclusively cycloid scales on the flanks and high dorsal fin ray counts.Kullander (1997: 286) examined one topotype "possibly… syntype [lapsus for paratype]" of C. guentheri (INPA 975; probably a paratype), an adult male, and in spite of the color pattern differences between this specimen and the type-series of C. hemera (which were ascribed to sexual dimorphism and maturity), he concluded that C. guentheri was very likely a synonym of C. hemera.We examined the type series of both C. hemera (holotype, Fig. 7 a) and C. guentheri (holotype, Fig. 7 e), plus recently collected, additional material from the rio Aripuanã drainage (see Comparative material examined).In fact, comparisons between the morphometric and meristic data (Table 2) of the type-material of each nominal species failed to demonstrate any differences.
One problematic feature that might putatively diagnose Crenicichla guentheri from C. hemera is the type of body scales present in each nominal species.Kullander (1990: 214;1997: 286) remarked that body scales in Crenicichla hemera were mainly ctenoid, while Ploeg (1991: 34) noticed that body scales in C. guentheri specimens were mostly cycloid.Kullander (1997: 286) noticed that the tentative "syntype" (but probably not part of the material studied by Ploeg) of C. guentheri he examined had cycloid scales at the anterior third of the body, but mostly ctenoid scales on the posterior twothirds of the body.The re-examination of the type-series of both nominal species, and additional non-type material from the rio Aripuanã basin carried out during the present study, showed that the variation in the presence of cycloid/ctenoid scales on the flanks is large (as already pointed out by Ploeg 1991:34).For example, while the specimen ZUEC 6360 (85.1 mm SL) possesses a flank squamation similar to that of the holotype of C. hemera (83.7 mm SL, Fig. 8b), specimens MZUSP 37754 (93.0 mm SL, Fig. 8c), MZUSP 109231 (127.5, 167.0 [Fig.8d] and 231.5 mm SL) have the anterior one-fifth to one-half of the flanks covered with cycloid scales, being more similar in this regard to the holotype of C. guentheri (172.4 mm SL) in which the anterior half of the flanks is covered by cycloid scales and the posterior half with ctenoid scales (Fig. 8e).The degree of presence of cycloid scales, however, cannot be assigned to ontogenetic change, because in some relatively large specimens from the rio Aripuanã (e.g.ZUEC 6361 -127.5 and 231.5 mm SL) the flanks are covered entirely with ctenoid scales.We conclude that the degree of coverage with Also, as earlier advanced by Kullander (1997) based on the examination of one topotypical specimen of C. guentheri, all the type material examined of C. guentheri possesses a smooth preopercle.Finally, Kullander (1997) also noticed the presence of co-ossified infraorbitals 3 and 4 in the specimen of C. guentheri that he examined, and we confirmed the co-ossification of the same bones in the same specimen, and additionally, in the holotype (INPA 2884) and paratypes (INPA 1493, INPA 1495) of C. guentheri, as well as some of the non-types MZUSP 37754, MZUSP 109231, ZUEC 6360, and ZUEC 6361 (this character cannot be distinguished in all alcohol-preserved specimens, only in the ones that are relatively faded and/or dehydrated).We thus concur with Kullander (1997) and confirm the synonymization of C. guentheri with C. hemera.
The coloration of C. hemera, based on the examination of 69 specimens, 25.7-231.5 mm SL, shows a remarkable ontogenetic change from juveniles to adults.This change can be observed in specimens from approximately 80 mm of SL.Juveniles and subadults have a conspicuous lateral band 2-3 scales wide, pre-and postorbital stripes and caudal blotch without light ring or masked by the expansion of lateral band pigmentation (Fig. 7a).In faded or poorly preserved specimens, the lateral band can be faint and indistinct (Fig. 7b).The dorsal, anal and caudal fins present a light submargin and dark margin, and dorsal fin with many small brown dots.Adults usually have preorbital stripe masked by dark snout pigmentation and an inconspicuous lateral band, which is sometimes totally absent (Fig. 7c -e).The dorsal fin lacks small dots, the caudal blotch is faint, almost indistinct, and the light submargin and dark margin are more evident than in subadults.In mature females, the light submarginal area is slightly wider than in males.Except for the rounded abdomen of mature females, no pronounced sexual dimorphism was observed.Ploeg (1991) allocated C. guentheri into the C. saxatilis species group because of the presence of a humeral blotch.A dark blotch in the region just above the pectoral fin is indeed present in most specimens of C. hemera, but it seems to be actually a remnant portion of the lateral stripe rather than the typical distinct humeral blotch of the species belonging to the C. saxatilis species group.On the other hand, fourteen specimens (107.0-231.5 mm SL) show a pronounced humeral darkening.This kind of darkening can be noted in other Crenicichla, such the C. lugubris related species (Ploeg, 1991, Kullander, 1997) that undergo a similar ontogenetic change of color pattern.However, other diagnostic character states of Crenicichla hemera do not point to a close affinity either to species belonging to the C. saxatilis species group or to the C. lugubris species group, particularly the smooth preopercle and the E1 counts (too high for a species belonging to the C. saxatilis species group and too low for one belonging to the C. lugubris species group).
We concur with Kullander (1990bKullander ( , 1997) ) in considering C. hemera a distinctive species, not assignable to any of the currently recognized species groups within the genus.On other hand, and as pointed above, there is a close resemblance between C. hemera and C. chicha, which seems to indicate that both species are closely related, putatively sister taxa.
, and an intraspecific variation for this feature is observed in C. jupiaensis Britski & Luengo and C. mucuryna Ihering (H.R.V. pers.obs.).From the species of the C. missioneira group and from C. jupiaensis, C. chicha differs by having a suborbital stripe instead of suborbital stripe absent or reduced to one or a few small dots.It differs from C. mucuryna by having more scales in the E1 row (66-75 vs. 57-63 scalesaccording to Kullander & Lucena, 2006), and a color pattern without narrow dark vertical stripes on flanks.Another Crenicichla species possessing a smooth preopercular margin is C. hemera, which is discussed below.Some species of Teleocichla also have smooth preopercle, viz.Teleocichla centrarchus Kullander, T. gephyrogramma Kullander, T. monogramma Kullander and T. centiquasma Zuanon & Sazima.

Fig. 6 .
Fig. 6.Map of northern South America, showing distributions of Crenicichla chicha (circles) and C. hemera (squares).Type locality of each species as black symbols.A symbol may represent more than one collecting site.
Diagnosis.An elongated and medium-sized species of Crenicichla (maximum SL known 137.7 mm) with moderatesized scales on flanks.Crenicichla chicha can be easily distinguished from all species of Crenicichla by a set of character states in combination: 66-75 scales in E1 series; laterally compressed body (vs.cylindrical and robust body in most species of C. reticulata group); absence of a distinct humeral blotch (vs.presence in C. saxatilis group); smooth supracleithrum (vs.spiny projections on posterior margin of supracleithrum bone in C. wallacii group); smooth preopercular margin, absence of microbranchiospines and infraorbitals 3 and 4 co-ossified (vs.posterior margin of preopercle serrated or with irregular projections, microbranchiospines present on the 2 nd through 4 th gill arches and infraorbitals 3-4 separated in most Crenicichla species).

Table 1 .
Standard length in millimeters and proportional measurements in percents of standard length of Crenicichla chicha.N = number of specimens, SD = standard deviation; holotype measurements are also contained in the sample range.

Table 2 .
Morphometry and meristics of Crenicichla hemera (holotypes of C. hemera and C. guentheri, and the range of all specimens examined).N = Number of specimens, SD = standard deviation, frequencies in parentheses.