Alternative name: Anablepsoides gamae

Distribution. Known only from the Jari river drainage, lower Amazonas river basin, Amapá state, Brazil.

Etymology. Named after Cecile Gama in recognition of her pioneering ichthyological field studies in the Amapá state, Brazilian Amazon.

Distinguished from all other congeners, except A. amanan, by the color pattern of the caudal fin and anal fin in males, consisting of the dorsal portion of caudal fin orangish-red with dorsal margin white and narrow black outer border (vs. never a similar color pattern), a middle portion of caudal fin black with bright greenish-blue stripe extending from caudal peduncle to posterior portion of the fin (vs. never a similar color pattern), anal fin yellow with transverse red stripes on the posterior portion (vs. never a similar color pattern) and by having a continuous row of 6 neuromasts on the mandibular series (vs. 3 or 4 neuromasts on an anterior section and a single isolated posterior neuromast). Distinguished from A. amanan and all other species of the A. ornatus group by having a unique color pattern of flank in adult males, in which there are pairs of oblique rows of dark red dots, the dots of each posterior pair row being connected to form dark red oblique bars and each dot of the anterior pair row being usually connected to the posterior adjacent row (vs. never a similar color pattern) and by a unique color pattern on the head in females, consisting of a distinct not pigmented area between a zone of small brownish-grey spots on the post-orbital region and an oblique black bar crossing the middle of opercle (Fig. 4c) (vs. side of head pigmented, with small dark grey to black spots overlapped over opercular, post-orbital and infra-orbital region; Figs. 4a – b). Also distinguished from A. amanan by a longer pre-dorsal distance in males (81.3 – 84.6 % SL vs. 77.4 – 79.7 % SL).

Dorsal profile slightly convex from snout to end of the caudal-fin base. Ventral profile approximately straight, slightly convex on the pelvic-fin region. Body slender, depressed on the head, gradually becoming compressed posteriorly. Greatest body depth at vertical through the pelvic-fin base. Jaws short, snout slightly pointed in lateral view. Dorsal and anal fins small, extremity rounded, dorsal sub-rectangular, anal fin sub-triangular. Caudal fin oval, slender and long. Pectoral fin rounded, posterior margin reaching vertical through the pelvic-fin base in males, through urogenital papilla in females. Pelvic fin elliptical, extremity reaching anal-fin origin in males, reaching urogenital papilla in females. Pelvic-fin bases medially in close proximity. Dorsal-fin base posterior to anal-fin base; second proximal radial of dorsal fin between neural spines of 19th and 21st vertebrae, first proximal radial of anal fin between pleural ribs of 13th and 14th vertebrae. Dorsal-fin rays 6 – 7; anal-fin rays 10 – 11; caudal-fin rays 23 – 25; pectoral-fin rays 12 – 13; pelvic-fin rays 7. Scales small, cycloid. Body and head entirely scaled, except on jaws. Body squamation extending over anterior 20 % of the caudal-fin base; no scales on dorsal and anal-fin bases. Frontal squamation F-patterned; E-scales not overlapping medially; scales arranged in a regular circular pattern around A-scale without exposed margins; the transverse row of scales anterior to H-scale. Longitudinal series of scales 28; transverse series of scales 7; scale rows around caudal peduncle 12. No contact organs on flank and fins. Cephalic neuromasts: supraorbital 3 + 3, parietal 1, rostral 1, infraorbital 2 + 12 + 1, preorbital 2, otic 1, post-otic 1, supratemporal 1, median opercular 1, ventral opercular 1, preopercular 2 + 4, mandibular 6, lateral mandibular 1 – 2, paramandibular 1. Two neuromasts on caudal-fin base.

Color: Males. Flank greenish golden, with oblique row pairs of dark red dots, dots of each posterior pair row connected to form dark red oblique bars, each dot of anterior pair row usually connected to posteriorly adjacent row; red dots concentrated on posterior portion of caudal peduncle. Dorsum light brown with a segmented longitudinal dark brown stripe on lateral portion. The oblique dark grey bar between area just above pectoral-fin base and middle of opercle. Venter light grey. Side of head light grey, opercular and suborbital regions with dense concentration of small dark grey spots and blue iridescence on ventral portion of opercle; transverse black bar between orbits through chin. The ventral portion of the head with a dense concentration of small black spots, anteriorly bordered by not pigmented area just posterior to chin bar. Iris dark brown with a posteroventral silver spot. Dorsal fin white, with two dark reddish-brown transverse stripes.
Anal fin pale yellow, basal portion light blue with dark red dots, posterior portion light blue with two or three dark red transverse stripes. Dorsal portion of caudal fin orangish-red, dorsal margin white with narrow black outer border; the middle portion of caudal fin black, with bright greenish-blue stripe extending from caudal peduncle to posterior fourth of fin; ventral portion of caudal fin dark red to gradually black posteriorly. Pectoral fin hyaline. Pelvic fin yellowish hyaline. Females. Flank light grey, with oblique dark grey bars, often ventrally terminating in a black spot, and narrow longitudinal dark brownish-grey stripes. Dorsum light grey with a segmented longitudinal dark brown stripe on the lateral portion.
Venter light grey. Oblique black bar from the area just above pectoral-fin base to infraorbital region, through the middle of opercle. Side of head light grey, with a zone of small brownish-grey spots on the post-orbital region, separated from the oblique opercular bar by not pigmented area; transverse black bar between orbits through the chin. The head's ventral portion with great concentration of black spots anteriorly bordered by not pigmented area just posterior to the chin bar. Iris dark brown with a posteroventral silver spot. Dorsal fin hyaline, with two narrow dark grey transverse stripes. Anal fin hyaline with three transverse rows of dark grey dots. The caudal fin is hyaline with transverse rows of dark grey dots. Paired fins hyaline.

Remarks:

This species, just described at the end of 2013, looks very close to what we know as Rivulus obscurus. (See images below.)

No records are available for breeding this species but will not differ from how any other small Rivulus from the Anablepsoides species group reproduce. They are seen as very difficult breeders as they need special attention from the one who keeps the species. In general, keep the water level very low at a max of 10 cm and provide shelter using a thick layer of floating plants and leaves at the bottom. If fed well with small live food like Artemia and mosquito larvae, then collect the fry from the surface or leave them with the parents to grow up

Best to provide them with brownish, soft, and acid water with pH as low as 4,5 to 5,5 pH. Most likely, eggs are produced only in low numbers because they are relatively big (2 mm) for such small fishes.

Remarks :

First of all, live animals are needed for further study on the reproduction and the behavior of this new species.