Hypsolebias martinsi, Britzke, Ricardo, Nielsen, Dalton T. B. & Oliveira, Claudio, 2016

Britzke, Ricardo, Nielsen, Dalton T. B. & Oliveira, Claudio, 2016, Description of two new species of annual fishes of the Hypsolebias antenori species group (Cyprinodontiformes: Rivulidae), from Northeast Brazil, Zootaxa 4114 (2), pp. 123-138 : 129-132

Hypsolebias martinsi , new species

( Fig. 4 , Table 1 )

Hypsolebias aff. antenori . Ponzetto et al., 2016.

Holotype. ZUEC 10791, male 27.5 mm SL: Brazil, Ceará, Amontada, temporary pool near Rio Icaraizinho, 03° 11’4.72’ S 39° 44’ 58.3’W, altitude 42 m, 0 2 Jun 2011. Col. Charly Orly & Dider Pillet.

Paratypes. ZUEC 10790, 0 2 male (24.8 mm SL), 0 1 female (26.4 mm SL), LBP 17862, 1 male (34 mm SL), 0 3 females (28.6–29.3 mm SL). Same date as holotype.

Diagnosis. Males of Hypsolebias martinsi differ from males of the remaining species of the Hypsolebias antenori species group by: absence of vertical bars in body (vs. presence of vertical bars at least in preserved specimens), thin metallic greenish line between black distal stripe and subdistal zone orange, opaque white dots on body (vs. absence of light white or light blue dots), 1–2 small filaments on dorsal and anal fins (2–6 long black filaments), longer pre-dorsal length (52.5–52.7% SL vs. 48.1–52.3% in H. nitens and 47.6–50.7% in H. coamazonicus ), shorter caudal-fin length (27.4–31.2 vs. 33.1–35.8% in H. antenori and 36.9–43.2% in H. pterophyllus ), lower head depth (86.6–90.6% vs. 91.8–102.2 in H. guanambi and 106.9–121.1 in H. mediopapillatus ), shorter head width (54.0–56.6% vs. 58.8–60.5% in H. guanambi and 74.7–78.4% in H. antenori ), dorsal-fin origin on vertical through anal-fin (vs. posterior origin of anal fin in H. antenori , H. macaubensis , H. ghisolfii , H. igneus , H. flavicaudatus , H. nudiorbitatus , H. nitens , H. gilbertobrasili , H. sertanejo , and H. pterophyllus , or anterior origin of anal fin in H. mediopapillatus , H. janaubensis , and H. coamazonicus ).

Females of H. martinsi are distinguished from other females of the H. antenori species group by having: shorter caudal-fin length (26.7–30.3% SL vs.32.3–36.8% in H. janaubensis and 34.4–38.8 in H. sertanejo ), lower head depth (78.1–83.1% vs. 86.6–100.1% HL in H. janaubensis and 106.6–121.1% HL in H. mediopapillatus ), smaller head width (56.9–58.2% vs. 59.3–63.4% HL in H. janaubensis and 69.6–82.5% HL in H. ghisolfii ), smaller eye diameter (22.9–24.6 % vs. 25.7–32.9% HL in H. ghisolfii and 31.8–34.8% HL in H. gilbertobrasili ).

Hypsolebias martinsi differs from the H. antenori species group by: absence of bars in body (vs. gray bars present only in preserved material), fewer numbers of dots on body and unpaired fins (vs. many dots on body and unpaired fins), 1–2 short black filaments at the tip of dorsal and anal fins (vs. 2–3 long filaments), yellow color absent from unpaired fins (vs. present).

Description. Morphometric data presented in Table 1 . Largest specimen examined 34.2 mm SL. Body relatively deep, compressed, greatest body depth at level of pelvic fin base. Snout blunt. Urogenital papilla cylindrical and exposed in males, pocket-shaped in females. Dorsal profile convex from snout to end of dorsal fin base, slightly concave or straight on caudal peduncle. Ventral profile convex from lower jaw to the end of anal fin base, nearly straight on caudal peduncle. Eyes positioned on upper portion of side of the head. Tip of dorsal and anal fin pointed with filaments in males and rounded to slightly pointed in females. Tip of both dorsal and anal fins with two short filamentous rays in males; filaments absent in females.

Dorsal and anal-fin unbranched in males and females. Caudal fin subtruncated in males, rounded in females. Pectoral-fin elliptical. Posterior margin of each pectoral fin reaching vertical through base of fourth anal-fin ray in males, and between pelvic fin and first and second anal-fin ray in females. Tip of each pelvic-fin reaching base of first anal-fin ray in males and females. Pelvic-fin without interspace. Dorsal-fin origin on vertical through anal-fin in males; anal-fin origin on vertical through base of fist dorsal-fin ray in males. Dorsal-fin origin posterior to analfin origin in females, on vertical through base of 6th anal fin ray. Dorsal-fin origin between neural spines of 10th and 11th vertebrae in males, and neural spines of 13th and 14th vertebrae in females. Anal fin origin at pleural rib of 10th vertebra in males, and pleural ribs of 13th vertebra in females.

Dorsal-fin rays 20 in males, 15–16 in females, anal-fin rays 20 in males, 19 in females, caudal-fin rays 20–21, pectoral-fin rays 12–13, pelvic-fin rays 6.

Cephalic neuromasts: supraorbital 14–16, parietal 3, anterior rostral 1, posterior rostral with one lateral neuromast and one middle neuromast, infraorbital 2 + 20–22, preorbital 3, otic 1–2, post-otic 2, supratemporal 1, median opercular 1, ventral opercular 2, preopercular 15–16, mandibular 12–14, lateral mandibular 5–6, and paramandibular 1. One neuromast on each scale of lateral line. Two neuromasts on caudal-fin base.

Frontal squamation E-patterned; E-scales overlapping medially; no row of scales anterior to H-scale; Longitudinal series of scales 27–28; transverse series of scales 12; scale rows around caudal peduncle 16. Contact organs absent in males. Total vertebrae 27–28.

Coloration in life. Males: Sides of body light gray, with opaque white dots, bars absent. Venter pale orange. Opercular region light greenish. Iris light yellow, with dark gray bar. Dorsal fin gray with white dots; 1–2 short black filaments on tips of dorsal-fin and anal-fin. Anal-fin yellowish gray, with thin metallic greenish line between black distal stripe and subdistal zone orange, white small dots only present in yellow gray zone; anal-fin with 2–3 small black filaments. Caudal-fin gray with white dots and greenish distal stripe. Pectoral fins hyaline. Pelvic fins half orange and half black.

Females: Sides of body light gray, with 12–13 dark gray bars; venter pale orange; 1–2 rounded black spots on anterocentral portion of flank; 0-4 irregularly arranged rounded black blotches on caudal peduncle. Iris light yellow, with gray bar through center of eye. Anal-fin and caudal-fin hyaline. Paired fins hyaline.

Distribution ( Fig. 5 ). Only known from the type locality.

Habitat. Found in annual pools of the Brazilian semi-arid biome in northeastern Brazil that are characterized by low and irregular rainfall, as they are located near the Equator line and have higher temperatures year round. The pools in this biome have soil with some clay and plants of the genus Echinodorus .

Behavior in captivity. Agonistic behavior was not observed among males, females or between both. No fighting was ever observed, with all specimens maintaining their fins intact for the duration of the observation period. In aquarium, specimens of the new species demonstrated to be very pacific and not too prolific.

Etymology. The specific name is giving in honor of Dr. Itamar Alves Martins, for his contribution to South American ichthyology and herpetology.

Figures

FIGURE 4. Hypsolebias martinsi, ZUEC 10791, male, holotype, 27.5 mm SL: Brazil, Ceará, Amontada, temporary pool near Rio Icaraizinho. Photo by Guillaume Dethu.

FIGURE 5. Map of northeastern Brazil showing known localities for species of the Hypsolebias antenori species group.