Tropheops biriwira, 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 : 365-367

Tropheops biriwira , new species

Fig. 5 A–C

Pseudotropheus elongatus ‘yellow tail’, Ribbink et al. 1983 (part) Pseudotropheus sp. ‘ elongatus greenback’, Reinthal 1990 Tropheops sp. ‘ elongatus greenback’, Konings 2007

Holotype. PSU 12767, adult male, 67.7 mm SL, S 14°02.459’, E 34°49.296’, Otter Island , Lake Malaŵi, Malaŵi, Africa, 7 Feb. 2004, A. F. Konings & J. R. Stauffer Jr.

Paratypes. PSU 12768, 24 , (44.6 mm – 68.3 mm SL), same data as holotype ; PSU 12769, 7, (58.7 mm – 68.8 mm SL), at type locality, 16 Feb. 2004, J. R. Stauffer Jr.

Diagnosis. The steeply sloped vomer (75.3° in holotype), the small retrognathic jaw, and the presence of bicuspid teeth in the outer rows of both lower and upper jaws and enlarged conical teeth at the back of the jaws place this species in Tropheops . Tropheops biriwira (BD 26.8–32.1 % SL) cannot reliably be distinguished from other Tropheops spp. on body depth (23.6–34.5%). The breeding male of T. biriwira has green/light blue ground coloration with a green dorsal fin, while those of T. kumwera and T. kamtambo both have blue ground coloration and a blue dorsal fin. Females of T. biriwira cannot reliably be distinguished from those of T. kumwera , but lack a black submarginal band in the dorsal fin that characterizes female T. kamtambo . There are fewer tooth rows (range 2–5) on both upper and lower jaws in T. biriwira than in other species of Tropheops (range 6–8) except in T. kumwera and T. kamtambo . Tropheops biriwira can be distinguished from T. kumwera and T. kamtambo by an on average larger eye (HED 30.8–40.4% HL; VED 29.6–35.4% HL vs. HED 25.8–32.6% HL; VED 24.0–31.4% HL in T. kumwera and T. kamtambo ). Tropheops biriwira also has on average a shorter snout (SNL 26.5–37.8% HL) than T. kumwera (SNL 28.0–42.8% HL).

Description. Morphometric and meristic data in Table 4 . Elongate species (BD 26.8–32.1% SL) with greatest body depth at base of fourth or fifth dorsal-fin spine. Dorsal body profile with gradual downward curve to softrayed portion of dorsal fin then more acute curve to posterior origin of dorsal fin, gradual taper to caudal fin; ventral body profile between pelvic and anal fin flat with upward curve from anterior point of anal fin to caudal fin. Head profile straight to slightly convex between snout tip and interorbital area; snout with 80–90° (84° in holotype) angle with body axis; dorsal head profile round to dorsal-fin origin. Teeth in outer rows bicuspid anteriorly and unicuspid posteriorly; all inner rows have tricuspid teeth medially and unicuspid laterally, with greatly enlarged conical teeth on lateral part of upper jaw.

First dorsal-fin spine about one fourth length of last spine. Soft dorsal fin with subacuminate tip, fourth ray longest, reaching to 1/3 of caudal fin in both males and females. Pectoral fin rounded, paddle-shaped. Fourth ray longest, length reaching to 1/3 of caudal fin in both males and females. Caudal fin subtruncate to emarginate. Pelvic fin not to anal fin in female; length in male to first anal-fin rays.

Flank scales large, ctenoid; abrupt difference to small cycloid scales on breast and belly; cheek with 4–5 (mode 4) rows of small scales. Tiny scales from base to 3/4 length of caudal fin.

Color notes and photos of live breeding adults (PSU 12770).

Population at Otter Island ( Fig. 5 B–C). Males in territorial color with greenish-blue ground coloration and 5– 6 distinct brown bars. Caudal peduncle greenish-brown. Head brown with 1 light blue interorbital bar and green highlights. Anal fin greenish-brown with 4–6 yellow ocelli; green marginal band. Pectoral-fin rays brown with clear membranes ( Fig. 5 B).

Females with light brown ground coloration and 4–5 faint lateral dark brown bars. Belly and breast beige/ brown. Head with light brown coloration and 1–2 faint greenish/beige/brown interorbital bars; dark brown opercle spot with green highlights. Pectoral fin and pelvic fin brown with light blue margins bands ( Fig. 5 C).

Distribution. Tropheops biriwira is found at Mumbo and Otter islands.

Etymology. The name biriwira is from Chichewa meaning “green”, referring to the greenish color of males in territorial coloration. The specific epithet is used as a noun in apposition.

Figures

FIGURE 5. Tropheops biriwira. A. Holotype, PSU 12767, adult male, 67.7 mm SL, Otter Island, Lake Malaŵi, Malaŵi, Africa; B. Male in breeding coloration (approx. 62 mm SL) at type locality; C. Female (approx. 50 mm SL) at type locality.

Tables

TABLE 4. Morphological and meristic data for Tropheops biriwira from Otter Island, Lake Malaŵi, Malaŵi, PSU 12767, holotype; PSU 12768 / 12769, n = 31. Ranges include holotype.

Variable	Holotype	Mean Std Dev Min	Max
	PSU12767	PSU12768–12769
Standard length (mm)	67.7	57.6 7.1 44.6	68.8
Head length (mm)	21.1	18.8 2.3 14.9	22.6
Percent head length (%)
Snout length	33.3	33.8 2.3 26.5	37.8
Postorbital head length	39.2	40.4 1.3 37.9	42.8
Horizontal eye diameter	33.2	34.2 2.2 30.8	40.4
Vertical eye diameter	30.3	32.1 1.5 29.6	35.4
Preorbital depth	24.5	20.8 1.9 17.4	24.6
Cheek depth	24.3	22.7 1.6 20.2	27.7
Lower jaw length	30.9	32.6 2.5 26.9	37.5
Head depth	81.5	80.5 4.2 72.3	90.5
Percent standard length (%)
Body depth	29.3	29.5 1.4 26.8	32.1
Snout to dorsal fin origin	34.5	35.8 1.4 33.1	38.2
Snout to pelvic fin origin	37.5	37.9 1.0 36.3	39.7
Dorsal fin base length	62.3	61.1 1.4 58.0	63.4
Anterior dorsal to anterior anal	48.9	49.0 1.1 46.8	50.8
Anterior dorsal to posterior anal	63.5	63.1 1.1 60.6	65.0
Posterior dorsal to anterior anal	28.1	27.7 0.8 26.4	30.0
Posterior dorsal to posterior anal	13.5	13.5 0.6 12.5	14.8
Posterior anal to dorsal caudal	14.1	15.4 0.7 14.1	16.6
Posterior dorsal to ventral caudal	16.8	18.3 0.7 16.8	19.5
Anterior dorsal to pelvic-fin origin	32.6	32.3 1.2 29.4	34.8
Posterior dorsal to pelvic-fin origin	56.9	54.7 1.6 51.8	57.5
Caudal peduncle length	9.7	10.5 0.7 9.2	11.9
Least caudal peduncle depth	11.5	11.9 0.5 11.1	12.7
Meristics		Mode Frequency(%) Min	Max
Dorsal-fin spines	18	18 84.4 18	19
Dorsal-fin rays	9	9 75.0 8	10
Anal-fin spines	3	3 100.0 3	3
Anal-fin rays	7	8 87.5 7	8
Pelvic-fin rays	5	5 100.0 5	5
Pectoral-fin rays	13	13 90.6 12	14
Lateral line scales	32	32 56.3 31	33
Pored scales caudal	2	2 87.5 1	2
Cheek scale rows	4	4 65.6 4	5
Gill rakers 1st ceratobranchial	10	11 65.6 7	11
Gill rakers 1st epibranchial	3	3 84.4 2	4
Teeth outer left lower jaw	13	10 31.3 9	13
Tooth rows upper jaw	3	4 56.3 2	5
Tooth rows lower jaw	4	4 62.5 2	5