Crenicichla mucuryna Ihering, 1914

Kullander, Sven O. & Santos de Lucena, Carlos A., 2006, A review of the species of Crenicichla (Teleostei: Cichlidae) from the Atlantic coastal rivers of southeastern Brazil from Bahia to Rio Grande do Sul States, with descriptions of three new species, Neotropical Ichthyology 4 (2), pp. 127-146 : 129-131

Crenicichla mucuryna Ihering

Fig. 1

Crenicichla mucuryna Ihering, 1914: 335 (Type-locality: rio Todos os Santos, afluente do rio Mucury).

Material examined. 32 specimens, 33.9-113.3 mm, all from Brazil, State of Minas Gerais. MZUSP 2526 (1, 113.3 mm), rio Todos os Santos, tributary of the rio Mucuri , mun. Teofilo Otoni, 1908, E. Garbe , lectotype of C. mucuryna ; MZUSP 5385 (1, 69.9 mm) , same data as lectotype, paralectotype; MZUSP 5386 (1, 110.0 mm) , same data as lectotype, paralectotype; USNM 307807 (1, 84.0 mm), rio Mucuri , mun. Nanuque, 17°50’S 40°W ; USNM 318226 (28, 33.9- 81.5 mm), rio Mucuri about 9 km W of town of Presidente Pena along dirt road on Fazenda Gavião, mun. Presidente Pena, 17°41’S 40°55’W .

Diagnosis. A small species of Crenicichla of the C. lacustris group sensu lato, not known to exceed 113 mm, distinguished from all other coastal southeastern Brazilian species by presence of a row of 9-12 narrow vertical stripes along middle of side, most of which derived from doubling or tripling of vertical bars descending from dorsum vs. absence of narrow vertical stripes; absence of pattern of small dark scattered spots on side of body, vs. presence. Similar in low scale counts (E1 53-63) and color patter (narrow vertical stripes) to species of C. lacustris group from upper rio Paraná basin, viz. C. haroldoi (E1 scales 50-56) and C. jaguarensis (E1 scales 47-53), both distinguished by a long, wide suborbital stripe and a lateral band more prominent than vertical bars; C. jupiaensis (E1 scales 49-55) with narrow vertical bars extending all the way from dorsal-fin base to abdominal side, suborbital stripe modified into a group of spots, and caudal spot expressed as a vertical bar; and C. niederleinii (E1 scales 57-65), with narrow, but long suborbital stripe, and well-marked lateral band. From C. iguassuensis , C. mucuryna can be distinguished by color pattern (absence vs. presence of scattered dark spots on side, and presence vs. absence of narrow vertical stripes). Description. Based primarily on specimens over 50 mm. Largest male 113.3 mm, largest female 65.4 mm. Measurements given in Table 1 , counts in Tables 4-8 . See Fig. 1 for general aspect.

Comparatively elongate, body depth 16.3-22.5% SL. Head as deep as wide. Caudal peduncle longer than deep. Snout moderately long, rounded when viewed from above, moderately pointed in lateral view. Lower jaw slightly prognathous. Ascending premaxillary process reaching to or almost to 1/3 of orbit. Maxilla reaching to vertical from anterior margin of orbit. Upper lip thick and wide, folds not continuous but cutting into symphyseal wide thickening. Postlabial skin fold margin truncate. Orbit supralateral, not visible from below, chiefly in anterior half of head. Nostrils dorsolateral, about halfway between orbit and margin of postlabial skin fold and with low tubular margin but no anterior marginal skin flap. Vertical margin of preopercle smooth or with few irregularly distributed projections.

Flank scales strongly ctenoid. All scales on head, anteriorly on back (above about anterior ¼ of lateral line), along dorsal fin base, chest, and on belly below line from lower edge of pectoral axilla to anal fin origin and along anal fin base cycloid. Predorsal scales small, superficially embedded in skin, extending forward almost to transverse frontal lateralis canal. Prepelvic scales very small, superficially embedded in skin. Cheek fully scaled or narrowly naked ventrally and anteroventrally; 6-9 scale rows below eye, embedded in skin. Interopercle naked. Circumpeduncular scale rows 10-12 dorsally, 10-14 ventrally (total 22-25 including lateral lines).

Scales between upper lateral line and dorsal fin base 8-11 anteriorly, 4 posteriorly; 3 scale rows between lateral lines. Anterior upper lateral line scales slightly larger and more elongate than adjacent scales, remaining lateral line scales nearly the same size as adjacent scales; three scales impinging on each scale of anterior part, two on each scale of posterior part of upper lateral line; 2 scales impinging on each scale of lower lateral line. Dorsal, anal, pectoral, and pelvic fins without scales. Caudal fin squamation concave, marginally extending to near middle of fin.

First dorsal spine about 1/3-1/4 length of last; spines increasing in length to last but subequal from about 10th. Soft part of dorsal fin pointed in males, rounded in females, 7th- 8th rays reaching slightly beyond base of caudal fin. Soft anal fin with rounded tip, in both sexes reaching to base of caudal fin. Caudal fin rounded. Pectoral fin rounded, reaching about halfway to anal fin. Pelvic fin inserted well posterior to vertical from pectoral axilla, with acuminate tip, second ray longest, reaching about halfway to spinous anal fin or slightly beyond; anterior margin slightly thickened.

All teeth pointed, erect or slightly recurved. Outer row of teeth distinctly larger than inner teeth and larger anteriorly than posteriorly. Upper jaw with 4-5 inner rows; outer row teeth slightly movable or fixed, inner teeth fully depressible. Lower jaw anteriorly with 3 inner rows; all teeth inclinable or depressible.

Microbranchiospines very small, easily overlooked, but present externally on 2nd-4th arches.

Coloration in alcohol. Lateral line scales light with dark brown dot distally. Neither males nor females with small dark spots on sides as in other coastal Crenicichla species. Dark brown preorbital stripe from orbit running anteriorly and crossong lips to lower jaw. Dark brown postorbital stripe straight from orbit to dorsal end of opercle. Nuchal markings include blackish spot little above posttemporal and dark stripe along margin of predorsal squamation above sphenotic. Suborbital stripe black, very narrow, and short, crossing only 2-3 scale rows.

Both sexes with six wide brown bars or blotches between dorsal fin base and upper lateral line; first blotch contiguous with brownish blotch below upper lateral line, remaining blotches each transforming into 2-3 narrow dark brown vertical stripes, most intense between levels of lateral lines. Another dark bar across dorsal margin of caudal peduncle, not split like preceding vertical markings. In larger males, however, dark markings on caudal peduncle separated into smaller dark spots. Narrow vertical stripes number varies between 9 and 12.

Dorsal fin in males grayish with 2-3 rows of small dark brown spots. Caudal fin with small brown, light-ringed spot between rays D1-D3, and 6-7 vertical rows of small dark spots, most intense along middle rays. Anal fin grayish, with about 3 rows of dark spots posteriorly. In females, unpaired fins usually immaculate save for ocellar blotches, but three specimens (56.9-61.8 mm) have few dark spots on caudal fin, in one also on dorsal fin. In these females no dorsal ocellus present or fin only slightly darker in its place. Dorsal fin ocellus present in 8 females (52.7-65.8 mm) between rays 12-16, 12-17, 13-15, 13-18 (usually 13-17), deep black, ocellation varying from hyaline dorsal margin to complete hyaline ring. Caudal fin in females usually with middle portion darker than rest and caudal spot without light ring. Pelvic fins without pigmentation in both sexes.

Two juveniles, 33.9-39.5 mm, similar to adults in body and fin coloration, i.e. with vertical bars across sides and spotted fins.

Geographical distribution. Known only from three localities in the rio Mucuri drainage, in the upper rio Todos os Santos at Teofilo Otoni, in the rio Mucuri close to the mouth of the rio Todos os Santos, and at Nanuque ( Fig. 2 ).

Habitat. USNM 318226 was taken in a side branch of the main river with some rapids, to 1.25 m deep, the bottom sandy, with boulders. The surroundings were pasture with remnants of gallery forest and scattered inga trees.

Notes. Crenicichla mucuryna is different in overall morphology and color pattern from all coastal species of Crenicichla treated in this paper. It completely lacks the pattern of small dark spots covering the body and often the side of the head in one or both sexes that characterize the remaining coastal species. Instead it has a conspicuous pattern of narrow dark vertical bars across the middle sides, and males have an irregular pattern of dark blotches on the caudal peduncle. The barred pattern resembles that of species of Crenicichla from the upper Paraná drainage. Among those species, C. jupiaensis is notable for its numerous narrow vertical bars extending all the way from the dorsal fin base to the lower side. Crenicichla jaguarensis , C. haroldoi , and C. niederleinii have a distinct lateral band, but also narrow vertical bars crossing it. Like C. mucuryna , Paraná species have fairly low scale counts, E1 row scales ranging from 47-65, contrasting with the other species of the C. lacustris group (63-70, rarely fewer than 60). The sexual dimorphism is similar to that reported for C. missioneira and related species, in which males have a spotted caudal peduncle, but not females (Lucena & Kullander, 1992). However, in C. mucuryna , the irregular spots on the caudal peduncle represent homologues of the more anterior vertical bars.

Further comparison of C. mucuryna with the remaining coastal species of the C. lacustris group seems unwarranted, but the species should be reconsidered in a revision of the barred Crenicichla species from the Paraná drainage. The pattern of narrow bars may provisionally be taken as a synapomorphy, although vertical bars occur in a larger group of Crenicichla . It is notable that C. mucuryna only occurs in the upper rio Mucuri and is not syntopic with other species of Crenicichla . We believe that the upper Mucuri may represent an old part of the Paraná drainage, which was diverted to an Atlantic drainage and has remained isolated, but we are unable to propose a detailed historical scenario, especially since the Mucuri now is margined by coastal drainages with only species of the C. lacustris group, and the São Francisco drainage which has only species of the C. lepidota group. A large number of non-cichlid species were collected in association with C. mucuryna that seem for the most part to represent common coastal taxa at species or genus level.

Figures

Fig. 1. Crenicichla mucuryna, USNM 307807, 84.0 mm SL, rio Mucuri, Nanuque, State of Minas Gerais, Brazil.

Fig. 2. Collecting localities of Crenicichla lacustris and C. mucuryna in the coastal rivers of eastern Brazil. Mostimportant rivers are:1. Rio Paraíba do Sul; 2. RioDoce; and 3. Rio Jequitinhonha.A symbol may cover more than one collecting site.