Metriaclima nkhunguensis, Ciccotto, Patrick J., Konings, Adrianus & Stauffer, Jay R., 2011

Ciccotto, Patrick J., Konings, Adrianus & Stauffer, Jay R., 2011, Descriptions of five new species in the genus Metriaclima (Teleostei: Cichlidae) from Lake Malaŵi, Africa, Zootaxa 2738, pp. 1-25 : 17-19

Metriaclima nkhunguensis , new species

Fig. 8A –C; Table 6

Metriaclima sp. "blue reef": Konings 2001: 58.

Holotype. PSU 4603, 72.8 mm SL; Mozambique: Lake Malaŵi: Nkhungu Reef, 12° 58.801' S, 34° 45.837' E; A.F. Konings & J.R. Stauffer, 1 Mar 2006.

Paratypes. PSU 4604, 5; 65.3–73.3 mm SL; data as for holotype.

Diagnosis. A moderately-sloped head and bicuspid teeth in the outer row of the jaws place this species in Metriaclima . Both males and females are light blue, fading to white ventrally, distinguishing them from all other members of Metriaclima , except M. callainos . Male M. nkhunguensis are distinguished from those of the similarly colored M. chrysomallos from the Gome population, M. estherae , and M. callainos , the latter two species of the sediment-free rocky habitat, by the yellow base of the pectoral fin (vs. no yellow pigment in males of the other three species). Female M. nkhunguensis are light blue, lighter than those of the only other known species with allblue females, M. callainos , which are a darker cobalt-blue (female M. estherae are either brown or orange/red). Metriaclima nkhunguensis is further distinguished from M. callainos by a shorter lower jaw (mean 31.2, range 29.4–34.1 % HL vs. mean 37.5, range 34.9–43.3 % HL).

Metriaclima nkhunguensis

n=6

Description. Morphometric and meristic data in Table 6 . Dorsal snout profile slightly concave to straight; mouth cleft with slightly downward angle; jaws isognathous. Teeth on dentary in three rows, on premaxilla in three to four rows; outer row teeth typically bicuspid anteriorly and unicuspid posteriorly, inner rows tricuspid, innermost row unicuspid; lower pharyngeal jaw with numerous slender teeth with teeth in posterior row slightly larger. Portion of upper dental arcade normally visible in closed mouth. Tips of teeth in premaxilla and dentary in Vshaped line with anteriormost in upper and lower jaw furthest apart and separate in closed mouth. Lateral scales ctenoid.

Breeding males pale blue laterally fading to white-blue ventrally. Head entirely pale blue with white gular region. Dorsal fin light blue with white-blue lappets. Caudal-fin rays clear with blue membranes. Anal fin light blue and 1–5 orange ocelli. Pelvic fin light blue with white leading edge. Pectoral fin clear with orange base.

Females light blue fading to white ventrally. Head light blue/gray, white gular region. Dorsal fin light blue with orange lappets. Caudal fin light blue. Anal fin light blue with 1-4 orange ocelli. Pelvic fin light blue/gray with white leading edge. Pectoral fin clear with white base.

Distribution. Metriaclima nkhunguensis is endemic to Nkhungu and Minos reefs in Mozambique ( Fig. 1 ).

Etymology. The specific name refers to one of the reefs at which the species is endemic.

Figures

FIGURE 1. Map of Lake MalaŴi showing the locations of species discussed throughout the text.

FIGURE 8. A. Metriaclima nkhunguensis, holotype, PSU 4603, 72.8 mm SL; Mozambique: Lake MalaŴi: Nkhungu Reef. B. M. nkhunguensis, male in habitat at Nkhungu Reef, Mozambique; approx. 60 mm SL; not preserved. C. M. nkhunguensis, female in habitat at Nkhungu Reef, Mozambique; not preserved.

Tables

TABLE 6. Morphometric and meristic values of Metriaclima nkhunguensis from Nkhungu Reef. Mean and range include holotype.

Standard length, mm Head length, mm Percentage of standard length	holotype 72.8 22.3	mean 69.6 20.9	range 65.3–73.3 19.8–22.3
Head length Snout to dorsal Snout to pelvic Greatest body depth	30.6 29.8 38.1 31.9	30.1 31.1 37.5 32.9	29.1–31.0 29.8–33.1 36.5–38.1 31.6–34.1
Caudal peduncle length Least caudal peduncle depth	14.3 12.3	14.0 12.2	12.9–15.3 11.7–12.7
Dorsal-fin base length Anterior dorsal to anterior anal Anterior dorsal to posterior anal Posterior dorsal to anterior anal Posterior dorsal to posterior anal Anterior dorsal to pelvic-fin origin	62.5 53.7 64.9 29.5 15.9 36.2	61.4 52.6 63.7 29.6 15.2 36.1	58.5–62.6 51.5–53.7 62.1–64.9 28.0–32.0 14.1–16.4 34.6–37.5
Posterior dorsal to pelvic-fin origin Percentage of head length Horizontal eye diameter Vertical eye diameter Snout length Postorbital head length	59.8 32.6 33.1 29.4 39.4	59.5 34.0 34.3 27.1 38.3	58.3–60.2 32.6–35.8 33.1–35.3 24.6–29.4 35.6–40.6
Preorbital depth Lower-jaw length Cheek depth Head depth	23.5 29.7 24.5 91.6	21.1 31.2 24.8 92.5	19.0–23.5 29.4–34.1 23.0–26.3 89.4–96.3
Meristics Dorsal-fin spines	17	mode 17, 18	range 17–18
Dorsal-fin rays Anal-fin spines Anal-fin rays Pelvic-fin rays Pectoral-fin rays Lateral line scales	10 3 7 5 15 31	9 3 8 5 14 30, 31	9–10 3–3 7–8 5–5 14–15 30–31
Pored scales posterior to lateral line Cheek scales Gill rakers on first ceratobranchial Gill rakers on first epibranchial Teeth in outer row of left lower jaw Teeth rows on upper jaw	1 4 13 2 22 3	1 5 13 3 22 3	0–2 4–5 11–13 2–3 19–23 3–4
Teeth rows on lower jaw	3	3	3–3