Enigmatochromis lucanusi, Lamboj, Anton, 2009

Lamboj, Anton, 2009, A new dwarf cichlid genus and species (Teleostei, Cichlidae) from Guinea, West Africa, Zootaxa 2173, pp. 41-48 : 45-47

Enigmatochromis lucanusi , new species

( Figs. 1 & 2 ; Table 1)

Pelvicachromis sp. “Blue Fin” ( Lamboj 2005)

Holotype. NMW 95063, male, 44.7 mm SL; Guinea: Foto River near the town of Fria, north of Conakry, Konkoure River system. 10° 20.074’ N, 13° 43.431’ W, collected by W. M. Traore, November 2007.

Paratypes. NMW 95064, 2 males, 1 female, 32.9–45.3 mm SL, same collection data as holotype. NMW 95065, 2 males, 2 females, 1 undet., 32.8–40.6 mm SL, same locality as holotype, but collected in January 2004; 1 female, 1 undet. used for C&S after taking counts and measurements. NMW 95066, 5 males, 4 females, 32.8–44.3 mm SL, same locality as holotype but collected in February 2006, 2 males and 2 females used for C&S after taking counts and measurements. AMNH 238830, 2 males, 2 females 30.8–44.4 mm SL, same locality as holotype, but collected in January 2004. MRAC 2008-015-P-1-4, 2 males, 2 females, 33.1–43.9 mm SL, same locality as holotype but collected in January 2008.

None-types. In addition, 8 pairs of wild collected fishes and their F1-descendents were used for behavioural observations, but not included in morphological examinations or type series or other collections.

Diagnosis. Same as for genus.

Description. Measurements and meristic counts for holotype and 25 syntopic paratypes are presented in Table 1.

Small cichlid species with body moderately gracile, dorsal head profile smoothly rounded and short snout. Ventral body wall gently rounded to caudal peduncle. Caudal fin rounded. Caudal peduncle short, always deeper than long. Sexual dimorphism well-developed with males usually 10–15% larger than females, with soft dorsal and anal fin rays more elongated. First ray of pelvic fin always longest in males, in females of equal length or longer than second ray. In males, tips of pelvic fin reaching origin of anal fin.

Osteology and dentition. Infraorbital bones series with lachrymal and three additional tubular bones and a gap between 2nd and 3rd tubular infraorbital; lachrymal with four openings of laterosensory system. 23–25 total vertebrae (12–14 abdominal and 11 or 12 caudal).

Premaxilla with one or two, dentary with one to three rows of regularly set unicuspid teeth. Anteriorly in the lower jaw a few teeth oriented posteriorly, not buccally. Lower pharyngeal bone triangular, with unicuspid to weakly bicuspid teeth on lateral parts of this bone, and asymmetric bicuspid teeth in the central field. Gill rakers on first gill arch. Eight to twelve tuberculate gill rakers on ceratobranchials, 4–7 pointed gill rakers on epibranchials. Well-developed hanging pad on roof of the pharynx.

Scales. Cycloid, one or two rows of scales on cheek; four horizontal rows on opercle. Dark spot on outer edge of opercle unscaled. Chest-scales smaller than body scales, four or five scales between pectoral and pelvic fins. Upper lateral-line separated from dorsal-fin base anteriorly by three scales, at the 8th pored scale by one or one and a half scales, and at last pored scale by no or a half scale. End of upper lateral-line never overlapping lower lateral-line, and separated from beginning of lower lateral line by one to four rows of scales. About ¼ of caudal fin covered with scales, and all other fins unscaled.

Coloration. Live specimens of both sexes ( Fig. 2 ): Head and body pale brown to greyish brown. Dorsum somewhat darker than ventral parts of body. Dark scaleless spot on the outer edge of opercle, with a light blue margin on posterior edge. Upper lip brownish to yellow-brown, lower lip greyish to brown. Throat and ventral parts of branchiostegal membranes yellow, more prominent in dominant specimens. Dark longitudinal stripe sometimes visible on sides (in stressed, submissive, breeding and guarding individuals), at about height of lower lateral-line, from posterior edge of eye to end of caudal peduncle, but not extending onto caudal fin. Dark stripe from anterior edge of the eye to the middle of upper lip. Upper edge of eye golden-yellow. Lachrymal bluish, with a red to reddish horizontal stripe from angle of the mouth to anterior edge of preopercular. Pectoral fin clear.

Male specific coloration. Dorsal fin pale yellow, with red margin, followed by a thin white submargin, morer prominent in anterior portion of this fin. Upper half of caudal fin yellow, lower half reddish. Soft ray parts of dorsal fin and upper half of caudal fin with some to numerous black dots in individual variation. Base of anal fin yellowish, rest of this fin reddish to violet. Anterior edge of pelvic fins yellow, first soft ray dark grey to black, other parts of this fin pale reddish to pale violet. Body scales with pale greyish margins. Most ventral parts of opercle, suborpercle, interopercle and chest are yellow.

Female specific coloration. Spiny portion of dorsal fin iridescent blue, sometimes extending to first one to two soft rays, with a red margin, followed by a thin dark to black submargin. Rest of fin clear. One or two black dots in most posterior part of iridescent blue coloration in many individuals. Caudal fin clear to very pale reddish, without patterns or marks. Anal-fin base and most anterior parts bluish, rest of the fin clear to pale reddish. Anterior edge of pelvic fins black, as first soft ray dark, other parts of this fin reddish with thin blue vertical lines in some specimens. Lower parts of opercle, subopercle and interopercle are blue, also most anterior parts of chest. Flanks and belly region, up to about upper lateral line or higher in some individuals, are wine red.

Juveniles of both sexes (before getting adult coloration) exhibit a pattern of three or four rows of irregular dark spots on brown coloration, up to about 10–12 mm SL. With increasing size, sex-specific coloration is seen.

Preserved specimen coloration General coloration of both sexes: Head and body brown, darker dorsally. Cheek, throat, pre-pelvic and pre-pectoral regions of flanks and chest pale light brown. Lips greyish. Dark spot on outer edge of opercle. A dark longitudinal stripe visible in some individuals, reaching from posterior edge of eye to end of caudal peduncle, but not extending into the caudal fin. Dark bar from anterior edge of eye to angle of mouth.

Male specific coloration. The general preserved coloration of adult males is shown in the holotype ( Fig. 1 ). Anterior portion of dorsal fin greyish. Posterior portion of dorsal fin and upper parts of caudal fin yellowish to greyish, with numerous dark spots. Lower parts of caudal fin pale grey. Anal fin dusky grey to dark grey anteriorly, posterior portion pale greyish to pale reddish. Pelvic fins dark grey to reddish grey, and pectoral fins clear.

Female specific coloration. Belly dark grey to reddish grey. Anterior portion of dorsal fin bluish grey to dark grey, posterior portion of this fin clear with no up to two black dots. Caudal fin clear without any markings. Anal fin base dark grey, sometimes with a pale reddish flush, outer parts of fin clear. Pelvic fins reddish to reddish brown, with dark to black anterior edge, and pectoral fins clear.

Breeding behaviour. In aquaria, this species is a monogamous, pair bonding, cave spawner. Eggs are guarded by both sexes, but more intensively by the female. Hatching occurs after three days post-spawn. Larvae are normally deposited on the bottom of the cave, rarely in other caves nearby the original cave. Juveniles are free swimming 8 or 9 days post-hatching, and are guarded by both parents for about 5 to 6 weeks. Breeding and guarding individuals of both sexes regularly exhibit more aggressive and intensive coloration. The dark, longitudinal stripe that is typical for breeding and guarding specimens of both sexes in many other cave breeders of the chromidotilapiine lineage (e.g., Pelvicachromis , Congochromis , and Parananochromis ) is prominently visible in males, but is more rarely and weakly visible in females. In this character, females of Enigmatochromis differ from females of Pelvicachromis , Congochromis and Parananochromis , where a prominent dark, longitudinal stripe is typical for females (and only rarely for males) during the first 2 to 4 weeks when guarding fry.

Distribution. This species is thus far only known from type locality, the Foto River, what is a small savannah river near the bauxite mining town of Fria in coastal Guinea, north of Conakry, 10° 20.074’ N, 13° 43.431’ W.

Habitat. Detailed habit data for the type locality was provided by O. Lucanus. The river was 3–6 meters wide, and during the dry season only 30–90 cm deep with water visibility ~ 1.2 m. Water parameters measured during the dry season in February, 2006 were: General hardness 0, Carbonate hardness 0, pH 5.8, and temperature 24° C.

This site was ringed by dense forest and often fallen trees obstructing access to the water in many places. Margins of the river were densely overgrown by Anubias lanceolata , and exposed boulders and fallen trees have large clusters of Bolibitis heudelotti and other ferns ( Fig. 3 ). The river substrate consisted of fine gravel with a few larger rocks and boulders. Dense growths of Vallisneria were found where sunlight penetrated through the trees.

Enigmatochromis lucanusi occured syntopically at this site with Pelvicachromis humilis . Etymology. The species name is dedicated to the collector, aquarist and friend Oliver Lucanus.

Figures

FIGURE 1. Enigmatochromis lucanusi, NMW 95063, holotype, male, 44.7 mm SL; Guinea: Small creek near the village of Fria, north of Conakry. Scale bar = 10 mm.

FIGURE 2. Photographs showing coloration of Enigmatochromis lucanusi, nov. sp.: A) male, wild collected specimen in aquaria, ~ 40 mm SL, not preserved, displaying submissive coloration; B) male, wild collected specimen in aquaria, ~ 42 mm SL, not preserved, displaying aggressive coloration; C) female, wild collected specimen in aquaria, ~ 38 mm SL, not preserved, displaying submissive coloration; D) female, wild collected specimen in aquaria, ~ 39 mm SL, not preserved, displaying aggressive coloration; E) female, wild collected specimen in aquaria, ~ 38 mm SL, with juveniles at the age of approx. one week after swimming free and size of less than 12 mm TL, not preserved; F) aquarium bred juveniles with the age of app. one week after swimming free, size less than 12 mm TL, not preserved.

FIGURE 3. Type locality of Enigmatochromis lucanusi, Guinea: Foto River, near the town of Fria, north of Conakry. 10 ° 20.074 ’ N, 13 ° 43.431 ’ W. Photo by O. Lucanus.