Pelvicachromis signatus, Anton Lamboj, 2004

Anton Lamboj, 2004, Pelvicachromis signatus and Pelvicachromis rubrolabiatus, two new cichlid species (Teleostei, Perciformes) from Guinea, West Africa., Zootaxa 454, pp. 1-12 : 7-11

Pelvicachromis signatus , new species

(Figs. 5-7)

Pelvicachromis spec. “Bandi 1” or spec. “Guinea” -Linke & Staeck, 2002, 176; -Lamboj 1999, 57.

Holotype. ZMA 109.959, male, 72.3 mm SL; Guinea: Kolente basin, Bandi River, route Kangasili -Sougeta, 10° 11’ N, 12° 28’ W, J. Van Orshoven, Dec 1966 - Jan 1967 and Dec 1968.

Paratypes. All same data as holotype: ZMA 109.960, 1 female., 52.2 mm SL ; - ZMA 114.995, 5 males, 58.0-79.0 mm SL ; - ZMA 114.996, 2 females, 38.1-51.9 mm SL ; - MRAC 77-10-P-2-5, 2 males, 2 females, 52.1-71.5 mm SL .

Additional material: NMW 94838, 2 males, 54.7+58.3 mm SL, Guinea: Kolente basin, imported by F. Bitter Feb 1999, used for clearing and staining ; 2 males and 4 females, Guinea: Kolente basin, imported by F. Bitter Feb 1999, used for behavioral observations .

Diagnosis. A species of Pelvicachromis with the following combination of characters: 2 contiguous posterior infraorbital bones, 27 vertebrae (15 abdominal and 12 caudal), preorbital depth 25.0-28.7% HL, cheek depth 31.5-36.1% HL, 12-14 gill rakers on outer row of 1st branchial arch, 8 vertical dark bars on the body, black spots on the male dorsal fin and a large black spot at the base of the female caudal fin. With exception of a red margin, no red spots, dots or lines in the male caudal and dorsal fin.

Description. Measurements and meristic counts for holotype and 12 paratypes are given in Table 2. Sexual dimorphism and dichromatism well developed. First ray of pelvic fin always longest in males, tip of pelvic fin reaching to or overlapping origin of anal fin. In females, first ray of pelvic fin shorter or equal in length to second ray. Caudal fin rounded in females and small males, some rays in upper parts of this fin may posses a lobe-like elongation in large males. Some rays in posterior parts of dorsal and anal fins pronounced, but always much longer in males. Males about 1/3 larger than females.

Osteology and dentition. Infraorbital series with lachrymal and 2 tubular elements; lachrymal with 4 openings of laterosensory system. Vertebrae count: Total of 27, 15 abdominal and 12 caudal. Premaxilla with 1-2, dentary with 2-3 rows of unicuspid teeth. Anteriorly in lower jaws some teeth orientated posteriorly, not buccally. Lower pharyngeal tooth-plate triangular, laterally with teeth shouldered and unicuspid, centrally with bicuspid teeth.

Gill rakers on first gill arch: 7-8 tuberculate ceratobranchial, 5-7 pointed epibranchial. Well developed hanging pad on roof of pharynx.

Squamation. Cycloid, 2-3 rows of scales on cheek, 4 horizontal rows on operculum. Dark spot posteriorly on opercle without scales. Chest-scales smaller than body scales.

Upper lateral line separated from dorsal-fin base at highest point (8th pored scale) by 2-2 1/2 scales, on last pored scale by 1-1 1/2 scales. About 1/4 of caudal fin basally covered with scales; other fins without scales.

Coloration. Living specimens: Body pale brown, with head and dorsal parts slightly darker than ventral parts. Eight dark bars visible on body in most behavioral situations, e. g. when dominant and aggressive (but more evident in males). Anteriormost bar situated at about height of pectoral fin and posteriormost bar at end of caudal peduncle. Lips light brown. Iridescent blue lines on cheek and opercle. Body scales with dark margins, more prominent in males than in females. Pectoral fins colorless to pale yellow.

Male specific coloration (Fig. 6): Dorsal fin with red outer margin, followed by a white submargin and numerous black spots, sometimes connected to a black band in anterior portion of fin. Rest of fin pale brownish to pale yellow. Upper part of caudal fin possesses a thin red margin, sometimes followed by a thin white to blue submargin. Central portion of caudal fin yellow, lower portion pale blue. Anal fin yellow, with anterior portions pale violet. Pelvic fins yellow to violet with anterior edge dark blue to black and a thin blue margin.

Female specific coloration (Fig. 7): Greenish to yellowish blotch on flanks directly behind pectoral fins. Belly of ripe females rosy to violet. Dorsal fin pale blue to violet, with pale dark margin. Sometimes one or rarely two black spots in posterior parts of spiny dorsal. Caudal fin clear to pale blue, with a sizeable black spot on the most anterior portion. Anal fin light blue. Pelvic fins dark violet to black, with thin anterior margin of white to light blue.

Preserved specimens (Fig. 5): Coloration of head and body brown, with upper half darker than ventral parts. Black markings on fins are clearly visible, no or only weak other color patterns visible, e.g. dark vertical bars. Unpaired fins brownish.

Breeding behavior. No information from the wild available. In aquaria, a pair-bonding, cave-breeding species, as typical for the genus (Greenwood, 1987; Linke & Staeck, 2002; own observations). The female usually guards eggs and larvae; rarely the male does too. When swimming free, juveniles are guarded by both parents.

Distribution (Fig. 4). Kolente River basin in Guinea; possibly sympatric with P. signatus [[correct: P. rubrolabiatus ]].

Etymology. Signatus, Latin for “wearing markings” or “marked,” referring to the black markings in the dorsal fin of the male and the black spot on the caudal fin of the female.

Comparisons. Pelvicachromis signatus differs from all other members of the genus except P. humilis and P. rubrolabiatus in possessing 2 contiguous posterior infraorbital bones (vs. lachrymal and 3 tubular infraorbital bones with a small gap between tubular infraorbital 2 and 3). It differs from P. humilis and P. rubrolabiatus in color pattern, especially in presence of black spots on the male dorsal fin and a large black spot at the base of the female caudal fin. Also it differs from P. humilis in lacking red spots, dots or lines in the male caudal and dorsal fin (with exception of a red margin in dorsal fin and upper edge of caudal fin); additionally it tends to have a greater snout length (33.6-43.0% HL, mean 38.5 vs. 25.3-40.7% HL, mean 34.6), lesser caudal peduncle length (13.1-15.6% SL, mean 14.4 vs. 13.3-18.1% SL, mean 15.7) and a lower number of gill rakers on outer row of 1st branchial arch (12-14, median 13 vs. 12-17, median 15). Finally it differs from P. rubrolabiatus in having 8 vs. 7 vertical dark bars on the body and a greater preorbital depth (25.0-28.7% HL vs. 19.8-23.5% HL); additionally it tends to have a lower number of gill rakers on outer row of 1st branchial arch (12-14 vs. 14-16) and greater cheek depth (31.5-36.1% HL, mean 33.8 vs. 28.4-31.7% HL, mean 29.8).

Relationships. Pelvicachromis rubrolabiatus and P. signatus possess diagnostic characters of Pelvicachromis sensu Greenwood (1987) , as well as a color pattern featuring vertical bars not found in any other Pelvicachromis species except P. humilis . Additionally, the two new species share with P. humilis some other features mentioned by Greenwood (1987): A straight and sloping dorsal head profile, high counts for the abdominal vertebrae (14-15 for P. humilis , P. rubrolabiatus and P. signatus vs. 13-14 for congeners), a lower supraoccipital crest and an ethmoverine region longer which slopes at a somewhat lower angle and, in addition, a reduction in the number of tubular infraorbitals from 3 (as in congeners) to 2.

Taken in combination, this suggests that these two new species may be more closely related to P. humilis than to other species within the genus.