Enigmatochromis lucanusi Lamboj 2009

The new genus is distinguished from all other chromidotilapiine genera by a unique combination of characters. It possesses twelve scales around the caudal peduncle vs. (13 or 14 scales) in Limbochromis Greenwood 1987, (14-16 scales) in Chromidotilapia, Boulenger 1898, and (16 scales) in Benitochromis Lamboj 2001, Pelvicachromis Thys van den Audenaerde 1968 and Thysochromis Daget 1988. Among the remaining chromidotilapiine genera with twelve circumpeduncular scales this new genus is further distinguished from Congochromis Stiassny & Schliewen 2007 and Nanochromis Pellegrin 1904 by: an infraorbital series containing a lachrymal and three additional tubular bones, and a gap between the 2nd and 3rd tubular infraorbitals (vs. lachrymal and one tubular bone), plus the lateral line is clearly separated from the dorsal-fin base (vs. posterior part contiguous with the dorsal-fin base). It is distinguished from Divandu Lamboj & Snoeks 2000 by: an infraorbital series with a lachrymal and three additional tubular bones and a gap between the 2nd and 3rd tubular infraorbitals (vs. four tubular bones), only four openings of thelaterosensory system in the lachrymal bone (vs. five), the first ray of pelvic fin in adult females is of equal length or longer than second ray of this fin (vs. first ray always longer), being a pair-bonding cave breeder (vs. a mouthbrooder), and by well developed sexual dichromatism (vs. weakly developed). Finally it is distinguished from Parananochromis Greenwood 1987 by: an infraorbital series with a lachrymal and three additional tubular bones with a gap between the 2nd and 3rd tubular infraorbitals (vs. four tubular bones in some species of Parananochromis), juveniles with 3 or 4 rows of irregular dark brown to black dots on body (vs. maximum of 2 rows), and the first ray of pelvic fin in adult females of equal length or longer than the second ray of this fin (vs. second ray slightly longer or of equal length) (Ref. 81928).

In aquaria, the 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 inmany 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 thischaracter, 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 (Ref. 81928).

The river is 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.The 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. The river substrate consisted of fine gravelwith a few larger rocks and boulders. Dense growths of Vallisneria were found where sunlight penetratedthrough the trees (Ref. 81928).

Where it was collected, Enigmatochromis lucanusi occured syntopically with Pelvicachromis humilis (Ref. 81928).