Crenicichla mandelburgeri, Kullander, Sven O., 2009

Kullander, Sven O., 2009, Crenicichla mandelburgeri, a new species of cichlid fish (Teleostei: Cichlidae) from the Paraná river drainage in Paraguay, Zootaxa 2006, pp. 41-50 : 42-47

Crenicichla mandelburgeri , new species

Figs 1−7, Tables 1−2

Holotype. MHNG 2691.043 , adult female, 82.5 mm SL; Paraguay: Itapúa: Arroyo Tembey above falls; 1–3 November 1982, Expedition of MHNG.

Paratypes. All from Paraguay, Departamento Itapúa. — MHNG 2691.044 , 1 , 97.0 mm SL; Arroyo Tembey drainage: small tributary to Arroyo Tembey , 10 km S of CAICISA, San Rafael ; 4 Nov 1982, Expedition of MHNG. — MHNG 2691.045 , 14 , 60.8–113.2 mm SL; NRM 55478, 5 , 55.5–106.9 mm SL; Arroyo Tembey drainage: Arroyo Tembey, 4 km above rapids; 1–2 Nov 1982, Expedition of MHNG. — MHNG 2691.046 , 4 , 66.9–81.6 mm SL; Arroyo Poromoco, 10 km S of Santa María; 26 Oct 1982, Expedition of MHNG. — MHNG 2691.047 , 12 , 58.8–95.7 mm SL; Arroyo Poromoco; 26–27 Oct 1982, Expedition of MHNG. — NRM 42898, 1 , 78.6 mm SL; Arroyo Pirapó drainage: Pirapó, Arroyo Pirapó, inundated area; 21 Feb 1998, S.O. Kullander, et al. — NRM 42475, 1 , 98.2 mm SL; Arroyo Tembey drainage: Arroyo Guazúy, on side of road about 14 km before Naranjito; 24 Feb 1998, S.O. Kullander, et al. — NRM 22687, 1 , 36.1 mm SL; NRM 25926, 1 , 87.6 mm SL; Arroyo Tembey drainage: Balneario Yberá in stream ca 2 km from road Encarnación – Ciudad del Este , ca km 128; 24 May 1994, S.O. Kullander, et al. — NRM 41887, 3 , 23.3–23.5 mm SL; Arroyo Pirayuy drainage: Natalio, Arroyo Pirayuy, in the Balneario Pirayuy; 22 Feb 1998, S.O.Kullander, et al. — MNHNP 3678 , 2 , 66.1–81.1 mm SL; NRM 27910, 3 , 58.4–114.6 mm SL; NRM 27912, 2 , 89.7–103.2 mm SL; Arroyo Tembey drainage: Arroyo Tembey at Km 141 on Ruta 6 Ciudad del Este – Encarnación; 23 May 1994, S.O. Kullander, et al .

Diagnosis. Similar to other species of Crenicichla from Brazil ( C. mucuryna von Ihering ) and the Paraná River ( C. niederleinii ) by presence in young specimens of numerous narrow vertical bars along the side, replaced in adults by an irregular dark horizontal band. Distinguished by low number of scales in a lateral row, 44–56 vs. 57–63 in C. mucuryna and 56–65 in C. niederleinii . Distinguished from C. jaguarensis , in the upper Paraná River, by presence of numerous narrow vertical bars in young specimens, lateral band in adults 2–3 scales wide and running close to upper lateral line vs. 1–1½ scales wide and distinctly separated from upper lateral line, and suborbital stripe usually short and narrow and individual spots making up the stripe recognizable vs. stripe wide, long and almost uniformly pigmented. Distinguished from C. jupiaensis in the upper Paraná River by lower jaw prognathous, vs. jaws isognathous, preopercular margin serrated vs. smooth, and by colour pattern, C. jupiaensis not developing a lateral band. Distinguished from C. haroldoi , in the upper Paraná River, by caudal blotch present and distinct, vs. absent or indistinct, preopercle serrated vs. not serrated, and black dots marking lateral line scales absent vs. present. Distinguished from C. yaha and C. iguassuensis from the Urugua-í and Iguazú basins respectively, by dark lateral band along the side vs. a row of dark blotches along the middle of the side. Distinguished from coastal species C. maculata , C. punctata , C. lacustris , C. tingui , and C. iguapina by larger scales in the E1 row, 44–56 vs. 56–75.

Description. Largest male 114.6 mm SL, largest female 82.5 mm SL. Refer to Figures 1–5 for general aspect. Head about as wide as deep. Caudal peduncle slightly longer than deep. Snout moderately long, rounded from above, bluntly pointed in lateral view. Lower jaw slightly prognathous, its articulation below middle of orbit; ascending premaxillary processes reaching to 1/4 of orbit; maxilla reaching to or slightly surpassing 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 wide thickening. Postlabial skin fold margin truncate. Orbit supralateral, not visible from below, chiefly 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. Preopercle with regular serrations along vertical margin. Lateralis pores on head simple or with two small openings.

Flank scales strongly ctenoid. All scales cycloid on head, on dorsum above anterior 1/3 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 very small, deeply embedded in skin. Cheek naked anteroventrally; below eye 5–7 scales, embedded in skin. Interopercle naked. Scales in E1 row in Tembey specimens 44 (1), 46 (2), 47 (4), 48 (2), 50 (7), 51 (3), 54 (1), 55 (1); in Poromoco specimens 48 (1), 50 (1), 51 (1), 52 (3), 53 (2), 55 (1), 56 (1). Transverse scale row 14–15+1+5. Circumpeduncular scale rows 10–11 dorsally, 11–12 ventrally (23–24 including lateral lines).

Lateral-line scales in Tembey specimens 24/10 (3), 25/10 (3), 25/11 (3), 26/9 (1); in Poromoco specimens 23/12 (2), 23/13 (1), 24/10 (1), 24/11 (2), 25/10 (1), 25/11 (2), 25/12 (1); 2 scales continuing lower line onto caudal fin; one tubed accessory lateral-line scale on caudal fin, between rays D3 and D4, in one specimen. Upper and lower lateral lines overlapping by one scale. Scales between upper lateral line and dorsal fin 11 anteriorly, 3½ posteriorly; scale rows between lateral lines 2. Anterior upper lateral-line scales larger and more elongate than adjacent scales, remaining lateral-line scales nearly 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; 1–2 scales impinging on each scale of lower lateral line. Dorsal, anal, pectoral and pelvic fins without scales. Caudal-fin squamation extending to about 1/3 of fin, posterior margin of scaled area straight vertical.

First dorsal-fin spine about 1/4–1/3 length of last; spines subequal in length from 6th–9th. Soft part of dorsal fin with rounded or subacuminate tip, reaching to base of caudal fin or slightly beyond. Dorsal-fin count in Tembey specimens XXI.11(4), XXI.12 (2), XXII.10 (5), XXII.11 (4); in Poromoco specimens XX.11 (1), XXI.10 (2), XXI.11 (4), XXII.11 (2), XXIII.11 (1). Soft anal fin with rounded tip, reaching to or almost to base of caudal fin; anterior soft rays, lappets and margin of soft portion thickened. Anal fin count in Tembey specimens III.8 (6), III.9 (7), III.10 (1); in Poromoco specimens III.8 (7), III.9 (3). Caudal fin rounded. Pectoral fin rounded, 7th ray longest, reaching about halfway to spinous anal fin. Pectoral-fin rays in Tembey specimens 16 (12), 17 (1); in Poromoco specimens 15 (2), 16 (8). Pelvic fin inserted well posteriorly to vertical from pectoral axilla, with rounded or subacuminate tip, second ray longest, reaching about halfway to spinous anal fin; anterior rays and margin thickened.

All teeth pointed, slightly recurved, teeth in outer row fixed, teeth in inner rows inclinable, some depressible. Outer row teeth slightly larger than inner teeth. Outer row of teeth in upper jaw extending for nearly the length of the alveolar ramus of the premaxilla. Upper jaw with 3–4 inner rows anteriorly, one inner row continued almost as long as outer row. Outer row of teeth in lower jaw extending along 3/4 of length of jaw. Lower jaw with 2–3 inner rows anteriorly, one inner row continued posteriorly for half the length of the outer row.

Gill rakers externally on first gill arch 1–2 epibranchial, 1 in angle; ceratobranchial gill-rakers in Tembey specimens 8 (7), 9 (4), 10 (2), in Poromoco specimens 8 (7), 9 (2), 10 (1). Gill rakers on lower pharyngeal tooth-plate in Tembey specimens 11 (5), 12 (1), 13 (2), 14 (2); in Poromoco specimens 11 (6), 12 (2), 15 (1). Microbranchiospines present externally on 2nd–4th arches.

Lower pharyngeal tooth-plate ( Fig. 6) dissected from a 79.5 mm specimen, relatively compressed dorsoventrally, with moderately long posterior and anterior processes; tooth-plate length 85% of width; dentigerous area length 60% of width; 18 teeth in posterior row, 7 teeth in admedian row. Anterior teeth slender, subconical, slightly recurved, shape changing gradually to median and posterior teeth which slightly compressed, stout, with anterior shelf and posterior slightly antrorse cusp.

Vertebral counts in Tembey specimens 18+18=36 (1), 19+16=35 (3), 19+17=36 (4); in Poromoco specimens 19+16=35 (2), 19+17=36 (5), 20+17=37(2).

Coloration in alcohol. Chest, abdomen below level of pectoral-fin base, underside of head, and narrow zone along anal-fin base and ventral edge of caudal peduncle yellowish white. Cheek light brown, preopercle light grey. Snout dorsally and interorbital area dark grey. Sides and nape light brownish to yellowish; each scale with dark brown distal margin. Lateral-line scales light, each with a dark dot distally.

Dark brown stripe parallels postorbital stripe and turns transverse along anterior margin of predorsal squamation. Another dark brown stripe runs obliquely forward from gill cleft and along extrascapular row. Neither of these stripes crossing midline of nape. No spot at pectoral-fin base or any indication of a humeral blotch.

Preorbital stripe blackish, running from upper lip to orbit; more or less masked by dark snout pigmentation. Postorbital stripe composed of dark blotch immediately posterior to orbit and two parallel, partly confluent stripes on opercle. Suborbital stripe running from infraorbital 3 obliquely caudoventrad toward preopercular margin, usually ending before reaching preopercular margin; uniformly pigmented proximally but distally breaking up into dots, one on each scale crossed by stripe; rarely confined to spot at orbital margin ( Fig. 2).

Wide blackish lateral band with indistinct margins; three scales deep anteriorly, two scales deep posteriorly, lower margin running along lower lateral line tube row.

Five or six wide vertical blackish bars on dorsum below dorsal fin, and one indistinct dorsally on caudal peduncle. Bars incompletely divided vertically by lighter zone, and thus may appear as a variable number of pairs of bars. Light zone along upper lateral line separating bars from lateral band which, however, frequently showing dorsal expansions each opposed to a vertical bar division. Occasionally, anterior portion of lateral band reduced to row of continuous blotches corresponding in position to bars above.

Dorsal fin in females smoky with large black, slightly horizontally extended, ocellated blotch between spines 11–15, 12–17, 13–16, 14–16, or 14–17. Blotch narrowly margined by hyaline zone. In males dorsal fin grayish with 2–3 irregular rows of dark spots on spinous portion and one additional row of dark spots on soft portion.

Anal fin grayish with white lower margin and submarginal grey stripe; in males also a few dark spots on posterior membranes. Pelvic fin whitish, in females also dusked on anterior rays. Caudal fin dusky with scattered dark dots, dorsal and ventral margins black, posterodorsal and posteroventral margins white. Ocellated caudal blotch black, rounded, partially ringed with light.

Young specimens, up to 85 mm, usually with indistinct lateral band and its anterior to middle portion subdivided into about 5 narrow vertical double bars which extend down onto abdominal sides.

Distribution. Described from the Arroyo Tembey, with assigned samples from the Arroyo Poromoco, Arroyo Pirayuy, and Arroyo Pirapó, all right bank tributaries of the Paraná River in Paraguay ( Fig. 7).

Habitats. NRM 27910, 27912, and MNHNP 3678 were collected with electrofishing from rapids in a large stream, 5–10 m wide, to 1 m deep, with turbid, brownish water. Rocks came from road building. The slope of rapids was about 10°. Associated fauna included Crenicichla lepidota Heckel (Cichlidae) , Ancistrus sp. and Rineloricaria sp. (Loricariidae) , Bryconamericus sp. (Characidae) , Heptapterus mustelinus (Valenciennes) and Rhamdia quelen (Quoy & Gaimard) (Heptapteridae) .

All other sites where NRM material was collected were small, shallow brown-water streams up to about 3 m wide, with varying velocity and transparency, with bottom of sand and stones, and generally absent vegetation, mostly sampled in unfavorable high water conditions in February. Associated species were generally typical forest stream species such as species of Astyanax and Bryconamericus , H. mustelinus , Rineloricaria sp. , Rhamdia quelen , Oligosarcus paranensis Menezes & Géry (Characidae) , Apareiodon sp. (Parodontidae) , C. lepidota , and Gymnogeophagus cf. caaguazuensis (Cichlidae) .

Etymology. Named for Paraguayan ichthyologist Darío Mandelburger, Paraguayan co-coordinator of the Proyecto Vertebrados del Paraguay 1992–1999, during which field work C. mandelburgeri was collected.