Melanochromis loriae Johnson 1975

Konings, Adrianus F. & Stauffer, Jay R., 2012, Review of the Lake Malaŵi genus Melanochromis (Teleostei: Cichlidae) with a description of a new species, Zootaxa 3258, pp. 1-27 : 7-10

Melanochromis loriae Johnson 1975

( Fig. 3 ; Table 2 )

Melanochromis parallelus Burgess & Axelrod 1976

Material examined. USNM 214175, holotype, male, 100.6 mm SL, Malaŵi: Lake Malaŵi: “Chipoka Island”, Davies et al.; USNM 215029, holotype of M. parallelus , female, 76.2 mm SL, Malaŵi: Lake Malaŵi, Axelrod, Oct. 1974; USNM 215030, paratype of M. parallelus , male, 81.5 mm SL, same collection data as USNM 215029; USNM 215031, paratypes of M. parallelus , 2, 71.7–76.6 mm SL, Malaŵi: Lake Malaŵi: obtained from aquarium dealer, 1976; PSU 6042, 10, 69.1–85.5 mm SL, Malaŵi: Lake Malaŵi: Likoma Island: 12° 01.62’S, 34° 44.16’E, Konings, 7 Oct. 2009.

Diagnosis. Female and subadult M. loriae are distinguished from their congeners, except from those of M. melanopterus , M. lepidiadaptes , and M. kaskazini , by a white to cream coloured body (yellow to brown in other congeners), two black horizontal stripes on the flank, a black submarginal band in the dorsal fin, and black markings on the lower lobe of the caudal fin. Melanochromis loriae is distinguished from M. melanopterus and M. kaskazini by a shorter lower jaw, 31.9–35.2 %HL vs. 37.2–41.7 % in M. melanopterus and 36.4–44.6 % in M. kaskazini , and from M. lepidiadaptes by the higher number of tooth rows, 5–7 vs. 2 or 3. Male M. loriae in breeding colouration are distinguished from their congeners, except M. melanopterus , M. simulans , and M. robustus , by a broad black band in the spinous part of the dorsal fin, absent in all other congeners. Melanochromis loriae is distinguished from M. melanopterus and M. simulans by a shorter lower jaw, 31.9–35.2 %HL vs. 37.2– 41.7 % in M. melanopterus and 40% (Eccles, 1974) in M. simulans , and from M. robustus by a shallower caudal peduncle, 11.7–12.6 %SL vs. 12.9–14.4 %.

Description. Morphometric ratios and meristic values as shown in Table 2 . Small, oblong species (mean BD 35.5% SL) with greatest body depth at about base of ninth dorsal spine. Dorsal body profile with downward curve to caudal peduncle, in some specimens more acute curvature near posterior end of dorsal fin; ventral body profile straight to slightly convex between pelvic fins and vent, with upward taper along base of anal fin to caudal peduncle. Dorsal head profile rounded, with almost continuous curve between snout tip and dorsal fin origin; horizontal eye diameter (mean 28.7% HL) greater than preorbital depth; more than three quarters of eye (along horizontal axis) located in anterior half of head; moderate to steep head profile, straight to slightly convex snout and slightly retrognathous jaws; wide tooth bands with 5–7 rows in lower and upper jaws; teeth in outer row unequally bicuspid and teeth in inner rows tricuspid; single series of unicuspid teeth where outer and innermost rows meet.

Dorsal fin with XVIII–XIX (mode XIX) spines and 7–9 (mode 8) soft rays. Anal fin with III spines and 7 or 8 (mode 7) soft rays. First 3 or 4 dorsal spines becoming gradually longer posteriorly with first spine less than ½ length of fourth; last 15 spines becoming slightly longer posteriorly with last spine longest; soft dorsal with rounded (females) or rounded to subacuminate (males) tip, third or fourth ray longest, not reaching caudal fin in females and extending to approximately base of caudal fin in males. Anal spines becoming progressively longer posteriorly; third or fourth ray longest, not reaching base of caudal fin. Caudal fin subtruncate to emarginate. Pelvic fin short, not reaching anal fin. Pectoral fin rounded, paddle-shaped, short, reaching vertical line through base of 11th or 12th dorsal spine.

Flank scales large, ctenoid; abrupt transition to small scales on breast; cheek with 4–5 (mean 5) rows of small scales; bands of small scales on proximal margins of caudal fin; 75–90% of caudal fin covered with tiny scales; no scales on other fins.

Melanochromis loriae holotype mean range Dorsal-fin spines 19 19 18–19

Dorsal-fin rays 7 8 7–9

Anal-fin spines 3 3 3

...... continue on next page Colouration. Breeding males: head dark blue/black with two light-blue interorbital bands; cheek and gular region black; nape dark blue/black. Body dark blue/black with solid light-blue midlateral stripe and more diffuse light-blue dorso-lateral stripe; caudal peduncle dark blue/black with blue midlateral stripe; belly and breast dark blue/black. Dorsal fin dark blue with broad black submarginal band and light-blue lappets, in some males posterior dorsal with yellow margin. Caudal fin with dark-blue/black membranes and some light-blue rays, light-blue margin with narrow yellow posterior edge. Anal fin black, with 0–3 orange/yellow ocelli on posterior margin and lightblue ventral margin. Pelvic fin black with light-blue anterior margin. Pectoral fin with gray/black rays and clear membranes.

Females: head gray/green on snout and nape, and cream/white on cheek and throat with two black interorbital bars and third bar on nape extending to dorso-lateral stripe. Body white/cream with broad black midlateral and dorso-lateral stripes, each 2–3 scales wide. Dorsal and anal fin white with broad black submarginal band, caudal fin white with clear margin and black spots and streaks throughout fin. Pelvic fin white with narrow white/light-blue anterior margin and black submarginal band. Pectoral fin clear.

Distribution and field observations. Melanochromis loriae has a wide distribution in the northern half of the lake. The northernmost points of distribution are Mphanga Rocks, Malawi, on the west coast of the lake, and Lutara, Tanzania, on the east coast. Kande Island, Malawi and Tumbi Point, Mozambique, are the respective southernmost points of distribution ( Fig. 1). This species is also found at the islands of Chizumulu and Likoma but not at Taiwanee Reef. M. loriae occurs in small numbers at most localities throughout its range, but at Ndumbi Rocks, a reef off the northwestern point of Likoma Island, it is sometimes found in foraging groups of more than 50 individuals. Besides females and non-breeding males, such groups often contain non-territorial males in full breeding colouration. The preferred habitat is mostly rocky with little sand, and the majority of individuals occur at a depth ranging between five and 20 meters ( Ribbink et al. 1983). Melanochromis loriae is an omnivore, feeding mainly from the Aufwuchs on rocks. In addition to algae, however, Ribbink et al. (1983) observed cichlid fry and catfish eggs in the stomach contents of six individuals collected at Likoma Island. Melanochromis loriae is attracted to stirred-up sediment, suggesting opportunistic feeding behavior. On several occasions one of us (AK) has observed adult females of M. loriae picking fungus and anchor worms ( Lernaea sp.) from larger haplochromines (non-mbuna). In all instances the afflicted fish approached the “cleaner” and made clear, by lying on its side or hovering in a slanting, head-up position, that it would like to have a “treatment”. In all cases the dorsal fin was presented first. The female M. loriae then picked vigorously at the fungus or parasite and tore it off. Although this visibly hurt the “client’, it remained in the typical position. When the cleaning process was complete, which might take more than a minute, the larger haplochromine would resume its normal swimming position and disappear. Cleaning stations, as seen in marine fishes, were not observed: after the cleaning was done the female M. loriae would disappear from the scene as well.

Figures

FIGURE 3. A. Melanochromis loriae, holotype, USNM 214175, male, 100.6 mm SL; MalaŴi: Lake MalaŴi: “ Chipoka Island ”, Davies et al.; B. M. loriae, male in breeding colouration (approx. 80 mm SL) at Thumbi West Island (population introduced by Davies et al.), Lake MalaŴi, MalaŴi; C. M. loriae, female (approx. 70 mm SL) at same locality as male.

Tables

TABLE 2. Morphometric and meristic data for Melanochromis loriae; holotype, our collection from Likoma Island (n = 10), and the types of the synonymous M. parallelus (n = 4). Ranges include the holotype.

Standard length, mm	100.6	78.1	69.1–100.6
Head length, mm	30.5	24.6	21.0–30.5
% standard length
Head length	30.3	31.5	30.3–33.0
Body depth	33.4	35.5	31.0–40.6
Snout to dorsal	30.5	34.5	30.5–37.9
Snout to pelvic	41.3	37.0	34.7–41.3
Dorsal-fin base length	62.6	61.2	59.5–62.9
Anterior dorsal to anterior anal	49.7	51.1	49.1–53.9
Anterior dorsal to posterior anal	63.7	63.8	63.0–65.2
Posterior dorsal to anterior anal	30.0	30.2	28.8–31.5
Posterior dorsal to posterior anal	15.7	15.8	15.1–16.8
Posterior dorsal to ventral caudal	19.2	18.5	16.3–19.8
Posterior anal to dorsal caudal	21.0	21.4	19.9–22.9
Anterior dorsal to pelvic-fin origin	34.9	35.3	32.1–38.3
Posterior dorsal to pelvic-fin origin	52.3	58.5	52.3–63.7
Caudal-peduncle length	15.3	14.7	11.9–16.7
Least caudal-peduncle depth	12.2	12.4	11.7–12.6
Pectoral-fin length	21.3	23.6	21.3–25.0
Pelvic-fin length	25.4	25.1	21.7–27.6
% head length
Snout length	36.2	33.8	29.9–37.2
Postorbital head length	40.3	41.6	40.0–43.0
Horizontal eye diameter	23.9	29.0	23.9–31.0
Vertical eye diameter	24.1	28.4	24.1–30.9
Head depth	96.9	92.2	81.7–96.9
Preorbital depth	21.5	20.8	18.7–22.4
Cheek depth	23.1	22.5	20.1–24.5
Lower-jaw length	33.3	33.6	31.9–35.2
Interorbital width	28.5	25.9	24.3–28.5
Premaxillary length	24.7	25.6	23.8–28.6
Meristics	holotype	mode	range