Aphyosemion flavocyaneum Chirio, Legros & Agnèse, 2018

Agnèse, Jean-François, Chirio, Laurent, Legros, Olivier, Oslisly, Richard & Bhé, Hervé Mvé, 2018, Unexpected discovery of six new species of Aphyosemion (Cyprinodontiformes, Aplocheilidae) in the Wonga-Wongué Presidential Reserve in Gabon, European Journal of Taxonomy 471, pp. 1-28 : 9-12

Aphyosemion flavocyaneum Chirio, Legros & Agnèse sp. nov.

urn:lsid:zoobank.org:act:1C559D3D-38A3-4322-A7CF-BEBC547D4D8D

Fig. 4 A–D, Table 3

Etymology

The specific epithet refers to the main colours of this species (blue and yellow).

Material examined

Holotype

GABON: adult ♁, 32.3 mm SL (43.2 mm TL), Lake Ndaminzé 0.42874 S, 9.54502 E, 115 m a.s.l., field reference code CHRSP1 - Lac Ndaminzé, 13 Apr. 2014, Laurent Chirio leg. ( MRAC 2016-019 -P-1).

Paratypes

GABON: 3 ♁♁, 6 ♀♀, 21.3 –27.5 mm SL, same collection data as for holotype ( MRAC 2016-019-P- 2–10).

Differential diagnosis

Distinguished from other species of Chromaphyosemion by its blue anal fin with no submarginal red band (vs species with a submarginal red band present), except for A. poliaki , and very rare specimens of A. melanogaster and A. malumbresi . Differs from the latter species through a combination of the following features: flanks and venter yellow-orange with no red punctuation (vs flanks bronze, venter brown-orange, regular red dots; flanks yellow-green, venter yellow-green with a black zone, irregular lines of red dots; flanks bluish-white, venter bluish with a black zone, regular red dots), blue iridescent scales on the ventral region close to the caudal peduncle (vs red scales or black scales), black alpha-shaped mark on the pre- and post-opercular region (vs no alpha-shaped mark, only a few red macules), anal fin blue with an orange portion on the basal region with no punctuation except black dots on basal and/or posterobasal portions (vs anal fin blue-green with many red dots; yellow-green with red dots; bluish-white with red dots).

Colouration of live males ( Fig. 4A )

FLANKS AND VENTER. Yellow-orange with no red punctuation, two greyish lateral stripes on ventral region close to caudal peduncle with some blue iridescent scales. Two rows of paradorsal golden scales in dorsal region from operculum to caudal peduncle with few black macules.

HEAD. Yellow-orange. Premaxilla and mandible yellow-orange with black lower lips, orange infraorbital region with black macule, orange post-orbital region with two black macules, yellow-orange pre-opercle with two black macules, yellow-orange opercle with two black macules; black macules on pre- and postopercular region reveal an alpha-shaped mark.

FINS. The dorsal fin is blue, but more orange near the insertion of the fin, and rows of black dots between rays. Anal fin blue with orange portion on basal region of fin, with no punctuation and no submarginal or marginal bands. Certain individuals may have some small black dots on basal region. Caudal fin blue with many carmine red dots and some carmine red streaks in upper and lower lobes; submarginal and marginal red bands absent. Acumens at apex of unpaired fins orange or white for dorsal fin, very short blue acumen for anal fin, and orange or white for caudal fin. Colour pattern of pelvic fins identical to anal fin with blue background and no submarginal band or marginal band. Pectoral fins translucent.

Colouration of live females ( Fig. 4B )

FLANKS AND VENTER. Pale brown, four lines of red dots from opercle to caudal peduncle, two greyish lateral stripes, venter yellow-green, white on basal portion. Two rows of paradorsal golden scales in dorsal region, from operculum to caudal peduncle with red dots.

HEAD. Premaxilla brown, mandible pale orange with black lower lips, brown supraorbital region, white infraorbital region with red macule, grey postorbital region with two macules, white pre-opercle, yelloworange opercle with one red dot.

FINS. Dorsal fin yellow-green, rows of red dots between rays. Anal fin yellow-green with rows of red dots between rays. Caudal fin yellow-green, blue-green on distal portion, with rows of red dots between rays. Pelvic fins translucent with yellow-green reflection, red dots, blue reflection on edges. Pectoral fins are translucent.

Colouration of ethanol-preserved males and females ( Fig. 4 C–D)

FLANKS AND VENTER. Flanks of males grey-yellow with three short lines of red dots, venter grey-yellow with no red punctuation. Two rows of paradorsal red scales in brown dorsal region from operculum to caudal peduncle. Flanks of females grey-yellow, three lines of red dots from the opercle to the caudal peduncle. Two rows of paradorsal red scales in the brown dorsal region, from the operculum to the caudal peduncle.

HEAD. Premaxilla and mandible of male grey with black lower lips, infraorbital region has red macule, opercle with one red macule; very dark macules in post-opercular region. Head of female with a black lower lips, infraorbital region with a red macule. Head of female with black lower lips, infraorbital region with red macule.

FINS. Male dorsal fin grey-blue with rows of red dots between rays. Anal fin grey-blue with some small red dots in posterobasal region. Caudal fin grey-blue with many red dots and some carmine red streaks in upper and lower lobes. Female dorsal fin greyish, with rows of red dots between rays. Anal fin greyish, with rows of red dots between rays. Caudal fin greyish, with rows of red dots between rays.

Distribution and habitat

This species has been found at seven localities (for three of them, specimens have not been studied or deposited in a museum) in the Awagné River Basin ( Table 1 , Fig. 1 ), has never been found elsewhere and seems to be endemic to this hydrographic basin. It lives in small, secondary rivers and small, forest streams, often with a sandy bottom, where it can be found along the riverbanks. It hides quickly in water plants or dead leaves. In one locality, the bottom is muddy, the water quite stagnant and some fish have even been observed in small water holes. The uppermost locality is Lake Ndaminzé, which is about 1 km long: the species was found only under the shadow of large trees, hidden in the roots near the banks. This species was found in syntopy with an undescribed species of Aphyosemion and an undescribed species of Epiplatys . At one single locality in the Mbomba River, a tributary of the Awagné River, it was found in syntopy with Poropanchax stigmatopygus (Wildekamp & Malumbres, 2004) .

Figures

Fig. 4. A–D. Aphyosemion cyanoflavum Chirio, Legros & Agnèse sp. nov. A. Adult, ♁, from locality 9, not preserved. Photo by O. Buisson. B. Adult, ♀, from locality 9, not preserved. Photo by O. Buisson. C. Holotype, adult, ♁, from Lake Ndaminzé (MRAC 2016-019-P-1). D. Paratype, adult, ♀, from Lake Ndaminzé (MRAC 2016-019-P-2-10). E–H. A. flammulatum Chirio, Legros & Agnèse sp. nov. E. Adult, ♁, from locality 4, not preserved. F. Adult, ♀, from locality 4, not preserved. G. Holotype, adult, ♁, from the lower Aloumbé River (MRAC 2016-019-P-11). H. Paratype, adult, ♀, from the lower Aloumbé River (MRAC 2016-019-P-12-18).

Fig. 1. Collecting sites of the different populations. Black circles: Aphyosemion alpha Huber, 1998; Black triangles: A. flavocyaneum Chirio, Legros & Agnèse sp. nov.; red triangle: A. flammulatum Chirio, Legros & Agnèse sp. nov.; yellow triangles: A. barakoniense Chirio, Legros & Agnèse sp. nov.; red circles: A. pusillum Chirio, Legros & Agnèse sp. nov.; yellow circles: A. rubrogaster Chirio, Legros & Agnèse sp. nov.; red squares: A. aurantiacum Chirio, Legros & Agnèse sp. nov.