Metriaclima flavicauda, Li, Shan, Konings, Adrianus F. & Stauffer, Jay R., 2016

Li, Shan, Konings, Adrianus F. & Stauffer, Jay R., 2016, A Revision of the Pseudotropheus elongatus species group (Teleostei: Cichlidae) With Description of a New Genus and Seven New Species, Zootaxa 4168 (2), pp. 353-381 : 356-359

Metriaclima flavicauda , new species

Fig. 2 A–C

Pseudotropheus elongatus ‘yellow tail’, Ribbink et al. 1983 (part) Metriaclima sp. ‘ elongatus yellow tail’, Konings 2007

Holotype. PSU 12756, adult male, 97.2 mm SL, S 13°57.919’, E 34°48.167’, Zimbawe Rock , Lake Malaŵi, Malaŵi, Africa, 7 Feb. 2006, A. F. Konings & J. R. Stauffer Jr.

Paratypes. PSU 12757, 30 , (58.7 mm – 100.7 mm SL), same data as holotype.

Diagnosis. The presence of bicuspid teeth in the outer rows on both the upper and lower jaws and a moderately sloped vomer (46° in holotype) with a swollen rostral tip place this species in Metriaclima . Male and female M. flavicauda are distinguished by an elongate body (BD 23.6–28.5% SL) from all other species in Metriaclima (BD 28.8–40.8% SL) except M. tarakiki (BD 25.8–32.9% SL) and M. usisyae (BD 25.9–30.6% SL). Metriaclima flavicauda is distinguished from M. usisyae by a deeper preorbital bone (PRE 18.0–26.9% HL) and a longer snout (SNL 34.3–47.3% HL), which are 17.6–21.2% and 32.0–37.6% HL in M. usisyae , respectively. Based on the color pattern, males of M. flavicauda possess 5–6 black lateral bars, black pelvic fins, a black anal fin, a yellow caudal fin, and a black dorsal fin with yellow/orange spots distally. Males of M. usisyae have a yellow dorsal fin with a black submarginal band, a yellow pelvic fin and a yellow anal fin with a black leading edge. Males of M. tarakiki have 7–9 lateral bars, and gray-blue/dark gray caudal fin. Females of M. flavicauda can be distinguished from those of M. tarakiki by a bluish/brown ground coloration without lateral bars. In female M. tarakiki , the ground color is light brown with blue center-flank scales and dark brown lateral bars. Based on coloration alone, females of M. flavicauda cannot reliably be distinguished from those of M. usisyae . Metriaclima flavicauda also possess a relatively smaller eye than M. tarakiki (HED 20.5–30.6% HL vs. HED 27.2–36.3% HL).

Description. Morphometric and meristic data in Table 1 . Elongate species (BD 23.6–28.5% SL) with greatest body depth at base of fourth dorsal-fin spine. Dorsal body profile with gradual curve to caudal peduncle with highest point at fourth dorsal-fin spine; ventral body profile between pelvic fin and anal fin flat with upward curve to caudal fin. Anterior head profile straight to slightly convex between snout tip and interorbital; cleft of the upper and lower jaws with 23–39° angle with body axis; then round to dorsal-fin origin. Snout short with isognathic jaws. Teeth on lower jaw in 3–4 rows; upper jaw in 2–4 rows; outer rows bicuspid; inner rows tricuspid or unicuspid. First 3–4 Dorsal-fin spines longer posteriorly with first spine less than half length of fourth spine; last dorsal-fin spine slightly (10%) longer than fourth spine. Dorsal fin with subacuminate tip, fourth ray longest, about to base of caudal fin in both males and females. Pectoral fin rounded, paddle-shaped. Anal fin with 3 spines progressively longer posteriorly; third or fourth ray longest, length to base of caudal fin in both males and females, tip slightly longer than dorsal fin. Caudal fin subtruncate to emarginated.

Lateral scales large, ctenoid; small, cycloid scales on breast and belly; cheek with 3–5 rows of small scales. Rayed section of dorsal and anal fins with narrow proximal band of tiny scales; tiny scales from base to 50% length of caudal fin.

Color notes and photos of live breeding adults (PSU 12758). Males in territorial color with light blue ground coloration and 5–6 distinct black bars. Head black with 2 light blue interorbital bars; throat dark brown. Anal fin black with 4–6 yellow ocelli; light yellow marginal band. Pectoral-fin rays black with clear membranes ( Fig. 2 B).

Females with beige/brown/light blue ground coloration. Belly and breast white/beige. Head with beige/brown ground coloration and blue/green highlights; yellow/green opercular spot; interorbital green/light gray; throat white. Dorsal fin light brown/light blue without black submarginal band. Pectoral, pelvic, and caudal fins beige/ brown/light blue proximally, and dark brown distally ( Fig. 2 C).

Distribution. Metriaclima flavicauda is known from Zimbawe Rock (S 13°57.925’, E 34°48.189’) and Mumbo Island (S 13º59.5’, E 34°45.4’), Lake Malaŵi.

Etymology. The name flavicauda is a noun in apposition and derives from the Latin flavus meaning “yellow” and “ cauda ” meaning “tail”, and refers to the yellow tail of territorial males.

Figures

FIGURE 2. Metriaclima flavicauda. A. Holotype, PSU 12756, adult male, 97.2 mm SL, Zimbawe Rock, Lake Malaŵi; B. Male in breeding coloration (approx. 90 mm SL) at type locality; C. Female (approx. 65 mm SL) at type locality.

Tables

TABLE 1. Morphological and meristic data for Metriaclima flavicauda from Zimbawe Rock, Lake Malaŵi, PSU 12756, holotype; PSU 12757, n = 30. Ranges include holotype.

Variable	Holotype	Mean Std Dev Min	Max
	PSU12756	PSU12757
Standard length (mm)	97.2	79.4 13.0 58.7	100.7
Head length (mm)	29.8	24.3 3.9 17.6	30.5
Percent head length (%)
Snout length	38.5	38.2 2.7 34.3	47.3
Postorbital head length	42.9	41.5 1.5 38.8	44.8
Horizontal eye diameter	24.4	26.4 2.7 20.5	30.6
Vertical eye diameter	24.0	24.7 2.7 19.2	30.1
Preorbital depth	24.9	22.4 2.3 18.0	26.9
Cheek depth	26.9	25.3 2.2 21.0	29.8
Lower jaw length	45.1	40.2 3.3 34.3	47.5
Head depth	79.3	75.8 4.3 66.0	84.3
Percent standard length (%)
Body depth	28.5	25.9 1.4 23.6	28.5
Snout to dorsal fin origin	31.3	31.7 1.2 29.8	34.0
Snout to pelvic fin origin	35.6	35.4 1.4 33.4	38.6
Dorsal fin base length	61.5	61.7 1.9 57.7	65.4
Anterior dorsal to anterior anal	48.9	46.5 1.8 43.4	49.8
Anterior dorsal to posterior anal	63.6	63.0 1.8 59.3	65.8
Posterior dorsal to anterior anal	28.2	27.7 1.1 25.7	29.4
Posterior dorsal to posterior anal	14.7	13.7 0.7 12.5	15.6
Posterior anal to dorsal caudal	16.5	16.1 0.7 14.4	17.4
Posterior dorsal to ventral caudal	19.7	18.9 1.0 17.2	21.5
Anterior dorsal to pelvic-fin origin	31.2	28.5 1.6 25.9	31.3
Posterior dorsal to pelvic-fin origin	57.6	57.0 1.3 54.2	59.9
Caudal peduncle length	11.7	11.4 0.9 9.3	13.5
Least caudal peduncle depth	12.1	11.5 0.5 10.5	12.6
Meristics		Mode Frequency(%) Min	Max
Dorsal-fin spines	17	18 67.7 17	19
Dorsal-fin rays	10	9 58.1 8	10
Anal-fin spines	3	3 96.8 2	3
Anal-fin rays	8	8 83.9 8	9
Pelvic-fin rays	5	5 100.0 5	5
Pectoral-fin rays	13	13 93.5 12	14
Lateral line scales	35	33 54.8 32	35
Pored scales caudal	2	2 71.0 1	2
Cheek scale rows	4	5 58.1 3	5
Gill rakers 1st ceratobranchial	12	11 64.5 10	12
Gill rakers 1st epibranchial	3	4 71.0 2	5
Teeth outer left lower jaw	10	10 45.2 8	12
Tooth rows upper jaw	3	3 83.9 2	4
Tooth rows lower jaw	3	3 90.3 3	4