Parananochromis ornatus Lamboj & Stiassny, 2003, new species

Parananochromis ornatus, new species

(Figs 10-12)

Parananochromis sp. “Belinga” - Lamboj, 1999a: 126; Linke & Staeck, 2002: 149.

Holotype. MRAC A2-011-P-10, male, 51.0 mm SL; Gabon: Ivindo system, small creek on route Makokou-Ovan, 7km from Makokou, 0°34´N, 12°45´E, A. Lamboj, R. Guggenbühl, P. Sewer & A. Weissenbacher, Jul 1995.

Paratypes. Total of 18 specimens, 27.3 - 52.0mm SL, MRAC A2-011-P-11-14, 1 male, 3 females, 31.0-45.2 mm SL, Gabon: Ivindo system, tributary of riv. Aboy, route Makokou-Okondja, 0° 32´N, 12°56´E, A. Lamboj, R. Guggenbühl, P. Sewer & A. Weissenbacher, Jul 1995. - NMW 94632, 1 male, 1 undet., 27.3-30.04 mm SL, Gabon: Ivindo system, tributary of riv. Aboy, route Makokou-Okondja, 0° 32´N, 12°56´E, A. Lamboj, R. Guggenbühl, P. Sewer & A. Weissenbacher, Jul 1995. - AMNH 230704, 1 male, 3 females, 29.5-39.1 mm SL, Gabon: Ogowe system, Okondja, creek south of Okondja about 1 km south of 98-045 site 2, Muddy water. M.L.J. Stiassny et al., Jan. 1998. - AMNH 232113, 1 male, 1 female, 37.7-46.9 mm SL, Gabon: Ivindo system, Minkebe Gold Camp forest, 01°44´N, 12°48´E, S.A.Lahm, May 2000 - AMNH 233349, 2 males, 2 females, 30.2-52.0 mm SL, 3 cleared and stained, 30.2-46.8 mm SL, Gabon: Ivindo system, Minkebe Gold Camp forest, 0°43’N, 12°49’E, S.A. Lahm, May 2000 - CU 87043, 2 males 46.4-37.6 mm SL, Gabon: Ivindo system, Minkebe Gold Camp forest, 01°44´N, 12°48´E, S.A.Lahm, May 2000.

Differential Diagnosis. Parananochromis ornatus is readily distinguished from all congeners except P. brevirostris by the possession of 4 (versus 5) infraorbital bones. From brevirostris it differs in the possession of a scaled chest (naked in brevirostris), a well-developed pharyngeal pad, and usually 26 vertebrae (versus 25 in brevirostris).

Description. Measurements and meristic counts for holotype and 18 paratypes are given in Table 3.

The largest specimen in the type series is a mature male, 52.0 mm SL, but males regularly attains sizes of up to 70.0 mm SL in aquaria. Sexual dimorphism is well developed. Males are usually 20-30 % bigger than females and the soft dorsal and anal rays are produced. In adults of both sexes, the first ray of pelvic fin is usually the longest, but occasionally the second ray is slightly longer than the first in females. The tips of pelvic fins in larger males reach to or overlap the anus. Caudal fin is normally rounded in both sexes; sometimes in males the upper lobe has a slight prolongation. The snout is rounded or somewhat acute.

Osteology and dentition. Infraorbital series (Fig. 2c) with plate-like first infraorbital followed by 3 tubular elements. A small gap between the third and fourth infraorbitals. Infraorbital 1 with four openings of the laterosensory system. Usually 26 vertebrae with 13 precaudal and 13 caudal (25 vertebrae, 13 precaudal and 12 caudal in two individuals, 27 vertebrae, 13 precaudal and 14 caudal in one individual). Premaxilla and dentary with 2-3 (rarely 4) rows of acutely cusped, unicuspid teeth. Outer row teeth are slightly larger than those of the inner rows. Lower pharyngeal bone is narrowly triangular, with numerous, slender, shouldered unicuspid teeth on the lateral parts of the bone and larger asymmetric bicuspid teeth in the central field.

Gill rakers on first gill arch. Lower limb with 7-9 tuberculate gill rakers, 2-4 pointed gill rakers on the epibranchial. No microbranchiospines are present. A well-developed hanging pad is present on the pharynx roof.

Squamation. Cycloid, cheek usually with 2-3 scale rows but occasionally only a single row, 3 horizontal scale rows on the opercle. Dark unscaled spot on outer edge of opercle is well-developed. Chest scales are very small and deeply embedded, often with no free edge exposed, usually with 3-5 scales between pectoral and pelvic fin insertion. Upper lateral line separated from dorsal-fin base at its highest point (8th pored scale) by 1½-2 scales, at last pored scale by 0-½ scales. No overlap between the end of upper lateral line and lower lateral line. Caudal fin scaled basally for about one quarter of length; other fins are unscaled.

Coloration. Living specimens (Figs 11-12): Body greyish to brownish, darker dorsally than ventrally with a dark spot on the outer edge of the opercle. Dorsal fin and upper part of the caudal fin with a thin white margin, sometimes also with a thin red submargin. Anterior parts of the dorsal fin yellowish brown, anterior parts of the anal fin yellowish red. Posterior parts of the soft-dorsal fin, the upper 2/3 of caudal and the posterior parts of the soft- anal fin membranes clear or bluish, always with rows of reddish maculae in males, sometimes also in females but then fewer in number and intensity. Pelvic fins clear or reddish, with dark anterior edges; coloration is more intense in males than in females. Pectoral fins are clear. Normally a black midlateral band is visible, passing from the forehead, through the eye, and extending onto the first third of the caudal fin. A lachrymal stripe is well developed. Occasionally the midlateral band is indistinct or absent. The upper edge of the eye is red or yellow. A black band on the uppermost part of the back is sometimes present. This band may also be dispersed and blotchy or completely absent. Ripe females with a rosy belly. Lips are grey-brown. Dark margins on the body scales are particularly marked in males.

Preserved specimens (Fig. 10): Base body coloration is brown or dark grey, with the upper half darker than the ventral half. A midlateral stripe passing from the snout to the middle of the body (merging with the dark spot on the outer edge of the opercle) is usually visible. Unpaired fins are dusky grey to brownish. Soft-dorsal, soft-anal and caudal fin membranes always with rows of dark maculae in males, sometimes also in females but then less prominently marked.

Breeding behaviour. In aquaria a pair bonding, cave-breeding species. For further information on breeding biology see Lamboj, (1999a, as Parananochromis sp. “Belinga”).

Distribution (Fig. 3). The Ivindo system in Eastern Gabon and the Ogowe system in the vicinity of Okondja.

Etymology. From the Latin ornatus, handsome or splendid, in reference to the attractive coloration of the species.

Remarks. At the locality where the holotype was collected (Ivindo River system, small creek on route Makokou-Ovan, 7km from Makokou), P. ornatus was collected with specimens of P. brevirostris and P. longirostris. Thys van den Audenaerde (1968) mentions a taxon, Pelmatochromis sp. aff. caudifasciatus, as being widespread in the Ogowe system and also in the periphery of the central Congo. His brief description of this taxon (1968:368), which is presented as the “link” to Nanochromis, is probably P. ornatus although none of the material which Thys van den Audenaerde based his comments on has been located.