Melanochromis kaskazini, Konings-Dudin, Gertrud, Konings, Adrianus F. & Stauffer, Jay R., 2009

Konings-Dudin, Gertrud, Konings, Adrianus F. & Stauffer, Jay R., 2009, Descriptions of three new species of Melanochromis (Teleostei: Cichlidae) and a redescription of M. vermivorus, Zootaxa 2076 (1), pp. 37-59 : 44-47

Melanochromis kaskazini new species

( Figs. 4 , 7a ; Table 2)

Melanochromis sp. “Northern” Spreinat 1994

Melanochromis sp. ‘northern blue’ Konings 1995

Holotype. PSU 4546, 121.5 mm SL, male; Tanzania, Lake Mala ẁi, Manda , 10° 27.623’S, 34° 34.355’ E, Stauffer and Konings, 12 Feb. 2005.

Paratypes. PSU 4545 , 11 , 69.6–104.2 mm SL, data as for holotype ; AMNH 246004 , 2 , 75.2–99.8 mm SL, same data as for holotype ; PSU 4544 , 1 , 74.0 mm SL, Tanzania, Lake Mala ẁi, Lundu: 10° 42.535’ S, 34° 39.002’ E, Stauffer and Konings, 25 Jan. 2004 ; PSU 4556 , 1 , 67.3 mm SL, Tanzania, Lake Mala ẁi, Makonde, 9° 56.890’ S, 34° 27.301’ E, Stauffer and Konings, 8 Feb. 2005 ; PSU 4543 , 5 , 53.5–80.8 mm SL, Tanzania, Lake Mala ẁi, Ngwazi, 10° 10.485’ S, 34° 32.928 ’ E, Stauffer and Konings, 10 Feb. 2005 .

Diagnosis. Melanochromis kaskazini is distinguished from all congeners except M. lepidiadaptes by its territorial male coloration, because it exhibits incomplete reverse male-female stripe coloration. Males are cobalt blue and lack any light colored mid-lateral or dorso-lateral stripe. Females are distinguished from other Melanochromis , except M. parallelus , M. heterochromis , M. lepidiadaptes , M. melanopterus , and M. simulans , by a white body color, and differ from these five species by a yellow/orange anal fin, which is white with a black submarginal band in the others. Male M. kaskazini with breeding coloration are distinguished from those of M. lepidiadaptes by a shallower preorbital (21.9 % vs. 31.8 % HL; ranges: 19.3–26.9 vs. 26.9–35.6), a longer head (34.9 % vs. 31.9 % SL; ranges: 33.6–37.8 vs. 28.4–36.4), a shorter post-orbital head length (42.4 % vs. 47.8 % HL; ranges: 38.4–44.6 vs. 41.8–52.1), and a longer lower jaw (40.3 % vs. 36.8 % HL; ranges: (36.4–44.6 vs. 32.2–40.1).

Description. Morphometric ratios and meristic values appear in Table 2. Spindle-shaped species (mean BD 31.2% SL) with greatest body depth at about base of fourth dorsal spine. Dorsal body profile slightly convex anteriorly and increasingly curving downward along base of soft dorsal fin to caudal peduncle; ventral body profile gradually curving upward to caudal peduncle. Dorsal head profile straight between snout tip and interorbital, making 36–41° angle with body axis and often interrupted by slight bulge at tip of premaxillary pedicel, then rounding to dorsal fin origin; eye small (mean 26.6% HL), smaller than depth preorbital and positioned in anterior half of head with posterior orbit margin laying on vertical median of head. Long snout with wide, isognathous jaws; teeth on lower jaw in 2–4 rows with anteriormost of outer row large, unequally bicuspid and remaining (lateral) teeth unicuspid; inner row teeth small, unequally tricuspid tending to unicuspid in larger individuals; wide gap between outer row and inner rows. Teeth of lower pharyngeal bone well spaced with sharp cusp; teeth of posterior row enlarged. Lips thickened and concealing most of oral teeth with only larger tips of outer row teeth visible, when mouth opened.

Dorsal fin with XVI–XVIII (mode XVII) spines and 8–10 (mode 9) soft rays. Anal fin with III spines and 7 or 8 (mode 8) soft rays. First 6–8 dorsal spines gradually increasing in length posteriorly with first spine less than 1/3 length of eighth spine; last 10 spines slightly increasing in length posteriorly with last spine longest; soft dorsal with rounded or subacuminate tip, fourth or fifth ray longest, not or about reaching base of caudal fin. Anal spines progressively increasing in length posteriorly; fifth ray longest, not reaching base of caudal fin. Caudal fin subtruncate to emarginate. Pelvic fin not reaching anal fin in females; reaching first anal spine in males. Pectoral fin rounded, paddle-shaped, short, reaching vertical through base of 10 th or 11 th dorsal spine.

Flank scales large, ctenoid; abrupt difference to small scales on breast and belly; cheek with 2–7 (mean 4) rows of small scales. Upper branch of lateral line with 20–24 pored scales; lower branch 9–11. Small scales on proximal margin of dorsal fin and on proximal half of caudal fin.

Coloration. Breeding males: head and body cyan blue. Dorsal fin cyan blue with pale blue distal margin and white lappets. Caudal fin cyan blue with pale blue submarginal band and narrow yellow distal margin. Anal fin gray/blue with light blue distal margin and 3–5 small yellow ocelli. Pelvic fins gray/blue with white/ light blue leading margin. Pectoral fins with light-gray rays and clear membranes. When in full breeding color, males with blue color, which conceals broad black stripes of subordinate males.

Females: head cream white with blue highlights and two black interorbital bands on snout; gular region off-white. Body cream white with blue highlights and broad (2 full scales) black mid-lateral and dorso-lateral stripes; upper flank scales with light-blue margins; belly and breast off-white. Dorsal fin gray/white with narrow black submarginal band and white lappets with yellow tips; proximal black band on dorsal-fin base continuous with dorso-lateral stripe. Caudal fin bluish white with black spot at base, broad submarginal black band and yellow/orange margin. Anal fin gray proximally and orange/yellow distally. Pelvic fins clear/gray with yellow suffusion distally and with white leading margin and gray submarginal band. Pectoral fins with gray/yellow rays and clear membranes.

Field observations. Melanochromis kaskazini wanders through the intermediate habitat hunting larger invertebrates and small fishes. At most localities, generally solitary individuals are encountered, but at Makonde and Manda small foraging groups are frequently seen, in particular when SCUBA divers stir debris to which the predators are attracted. Most foraging groups consist of several males in varying degree of sexual maturity with usually a single large male in full blue color. Territorial or courting males have not been observed. Melanochromis kaskazini is most often seen at depths varying between 5– 40 m.

Distribution. Melanochromis kaskazini was encountered along the northeastern shore between Nkanda (9° 33.352’ S, 34° 6.479’ E) and Lundu (10° 42.535’ S, 34° 39.002’ E) ( Fig. 1 ). Lundu appears to be the southernmost margin in the distribution of other species as well. We found no apparent barrier in the northernmost part of its distribution that would explain why it was not found north of Nkanda. Another predatory species of Melanochromis , an undescribed form referred to as Melanochromis ‘blue’ by Ribbink et al. (1983), occurs north of Nkanda. The population density of M. kaskazini is higher at Makonde and Manda than at other known localities.

Etymology. The specific epithet kaskazini means “northern” in Kiswahili, the language spoken along the shores of the species’ distribution.

Figures

FIGURE 1. Map of Lake Malaẁi with localities mentioned in the text.

FIGURE 4. Melanochromis kaskazini, holotype, PSU 4546, 121.5 mm SL, male; Manda, Lake Malaŵi, Tanzania.

FIGURE 7. a. A non-territorial male Melanochromis kaskazini (approx. 105 mm SL) at Ngwazi, Lake Malaŵi, Tanzania; inset: a female (approx. 65 mm SL) at Nkanda, Lake Malaŵi, Tanzania; b. two males of Melanochromis wochepa (approx. 60 mm SL) at Lumessi, Mozambique; inset: a female (approx. 50 mm SL) at same location; c. a male Melanochromis mossambiquensis (approx. 70 mm SL) at Minos Reef, Mozambique; inset: a female (approx. 55 mm SL) at same location.