Aphyosemion barakoniense 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 : 15-17

Aphyosemion barakoniense Chirio, Legros & Agnèse sp. nov.

urn:lsid:zoobank.org:act:93CAFA79-3B4F-4F39-8430-D9A0DB9A58C5

Fig. 5 A–D, Table 5

Etymology

The specific epithet refers to the river in which the species was found.

Material examined

Holotype

GABON: adult ♁, 39.9 mm SL (48.9 mm TL), lower Barakonié River , 0.47664 S, 9.26483 E, 5 m a.s.l., field reference code CHRSP3 - Basse Barakonié, 2 Mar. 2016, Laurent Chirio leg. ( MRAC 2016-019 -P-19).

Paratypes

GABON: 7 ♁♁, 10 ♀♀, 21.5–46.6 mm SL, same data as for holotype ( MRAC 2016-019-P-20-36); 12 ♁♁, 8 ♀♀, 20.7–37.5 mm SL, upper Barakonié River, 0.45815 S, 9.33465 E, 55 m a.s.l., field reference code CHRSP 3-Haute Barakonié, 3 Mar. 2016, Laurent Chirio leg. ( MRAC 2016-019-P-37-56).

Differential diagnosis

Differs from all other species in A. alpha group through combination of following features: head orange, flanks grey-mauve, ventral region orange (vs never same colour pattern), anal fin orange with some red dots (vs no punctuation or only black dots on posterobasal portion for A. flavocyaneum Chirio, Legros & Agnèse sp. nov. and A. flammulatum Chirio, Legros & Agnèse sp. nov.). Distinguished from all other species of Chromaphyosemion by alpha-shaped mark in pre- and post-opercular region (vs no alphashaped mark, only some red macules).

Colouration of live males ( Fig. 5A )

FLANKS AND VENTER. Flanks grey-mauve with two dark lateral stripes, three lines of very dark red dots from opercle to caudal peduncle. Ventral region orange with some blue iridescent scales between end of anal fin and caudal peduncle. Dorsal region brown, two rows of paradorsal copper scales in dorsal region from operculum to caudal peduncle with two lines of carmine red dots.

HEAD. Orange, premaxilla brown, mandible orange with black lower lips, with brown supraorbital region, orange infraorbital region with black macule, postorbital region orange with two black macules, orange pre-opercle with two black macules, orange opercle with three black macules; black macules on pre- and post-opercular regions reveal alpha-shaped drawings.

FINS. Dorsal fin blue on basal portion, orange on upper portion, yellowish on edge of fin, with rows of carmine red dots between rays, orange acumen on apex. Anal fin mauve on basal portion, orange on median portion, yellowish portion near the submarginal band, with some carmine red macules, regular, red submarginal band, blue marginal band, small orange acumen.Caudal fin light mauve, with tips of upper and lower lobes orange, red dots on median region, short red streaks in distal region and in upper and lower lobes, irregular red submarginal band, blue marginal band, orange acumens. Pelvic fins orange with no punctuation, submarginal red band, blue marginal band. Pectoral fins with orange reflections.

Colouration of live females ( Fig. 5B )

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

HEAD. Premaxilla brown, mandible yellow; orange zone on side portion with black lower lips, brown supraorbital region, white infraorbital region with black macule, orange postorbital region with two black macules, orange pre-opercle, and orange opercle with two black dots.

FINS. Dorsal fin intense orange, with rows of carmine red dots between rays. Anal fin orange on the median portion with no dots. Caudal fin intense orange near caudal peduncle, red dots between rays. Pelvic fins with orange reflection, blue reflection on edges. Pectoral fins translucent.

Colouration of ethanol-preserved males and females ( Fig. 5 C–D)

FLANKS AND VENTER. Flanks of males dark grey with three lines of red dots, venter grey-yellow. Two rows of paradorsal red scales in brown dorsal region from operculum to caudal peduncle. Flanks of females beige with two dark lateral stripes, six lines of red dots from opercle to caudal peduncle, venter greyyellow. Two rows of paradorsal red scales in grey dorsal region, from operculum to caudal peduncle.

HEAD. Premaxilla and mandible of male grey, with black lower lips, orange infraorbital region with black macule, orange pre-opercular region, orange opercle with one red macule; dark macules in postopercular region. Head of female with black lower lips, infraorbital region with red macule.

FINS. Dorsal fin of male orange with rows of red dots between rays. Anal fin orange with some small red dots, red sumarginal band. Caudal fin orange with many red dots on basal portion, red streaks on edge and in upper and lower lobes. Dorsal fin of female orange, with rows of red dots between rays. Anal fin orange, with red streaks between rays. Caudal fin orange, with rows of red dots between rays on median portion, red streaks on edge.

Distribution and habitat

This species has been found at only two localities in the Barakonié Basin ( Table 1 , Fig. 1 ) and never elsewhere. It seems to be endemic to this small, coastal hydrographic basin. In the upper Barakonié, where the river is less than 1 m wide, the fish live among roots or dead leaves in the middle of the river. In the lower Barakonié, where the river can be 2 to 3 m wide, they are not found in the main course, but only in small water holes of stagnant water close to the river, hidden among dead leaves and mud, and there, they can be very abundant. This species was found in syntopy with an undescribed species of Aphyosemion .

Figures

Fig. 5. A–D. Aphyosemion barakoniense Chirio, Legros & Agnèse sp. nov. A. Adult, ♁, from locality 7, not preserved. B. Adult, ♀ from locality 7, not preserved. C. Holotype, adult, ♁, from the lower Barakonié River (MRAC 2016-019-P-19). D. Paratype, adult, ♀, from the lower Barakonié River (MRAC 2016-019-P-20-36). E–F. A. pusillum Chirio, Legros & Agnèse sp. nov. E. Adult, ♁, from locality 10, not preserved. F. Holotype, adult, ♁, from the Okoyo River (MRAC 2016-019-P-57).

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.