Simpsonichthys antenori

Wilson J. E. M. Costa, 2007, Taxonomic revision of the seasonal South American killifish genus Simpsonichthys (Teleostei: Cyprinodontiformes: Aplocheiloidei: Rivulidae)., Zootaxa 1669, pp. 1-134 : 96-99

Simpsonichthys antenori (Tulipano)

(Figs. 62)

Cynolebias antenori Myers, 1952: 139 ( nomen nudum; based on specimens collected near Russas , Estado do Ceará, rio Jaguaribe floodplains, northeastern Brazil ).

Cynolebias antenori Tulipano, 1973: 23 (spring from specimens collected in Ceará, northeastern Brazil; neotype: MZUSP 56256 , from temporary pool 2.5 km N of Limoeiro do Norte , Estado do Ceará, rio Jaguaribe floodplains, approximately 5° 10’ S, 38°05’ W ).

Cynolebias heloplites Huber, 1981:1 ( type locality: lagoon at km 76 of the road between Fortaleza and Russas , Estado do Ceará, Brazil; holotype: MNHN 1981-1211 ).

Material examined

Brazil: Estado do Ceará, rio Jaguaribe basin: MZUSP 56256 , neotype, male, 43.7 mm SL; UFRJ 4864 , 43; temporary pool 2.5 km N from Limoeiro do Norte , approximately 5°10’S, 38°05’W; W. J. E. M. Costa, A. C. L. H. Bacellar, F. Pupo & E. Araujo, 15 May 1999. UFRJ 4878 , 6; temporary pool in Limoeiro do Norte ; same collectors and date. UFRJ 4867 , 176; UFRJ 4880 , 8 (c&s); temporary pool 1.5 km N of Limoeiro do Norte ; same collectors and date. UFRJ 4873 , 25; temporary pool in the road BR-304 near Aracati ; same collectors and date. MNRJ 4542 , 7; Russas ; W. Franca and A. L. Carvalho, 03 Aug. 1945. MNRJ 21260 , 4; road BR-116, km 138, Russas ; C. Cruz & M. C. A. Barbosa, 12 Jul. 1979. MNRJ 19465 , 3; Pedras, perto de Russas ; C. Cruz & M. Barbosa, 12 Jun. 1979. Coastal basins: MZUSP 38342 , 29; Pacajus ; G. C. Brasil, Sep. 1972. MNRJ 19478 , 10; Aquiras , road BR-116, km 30 ; C. Cruz & M. Barbosa, 12 Jul. 1979. Estado do Rio Grande do Norte: ZVC.P uncat. , 2; Mossoró; G. C. Brasil, Sep. 1972.

Diagnosis

Distinguished from remaining species of the S. antenori group by possessing short dorsal and anal-fin filaments in males, which reach caudal-fin base (vs. reaching between central and posterior portion of caudal fin, or surpassing it) and unpaired fins dark bluish gray in males (vs. pink, yellow or orange).

Description

Morphometric data appear in Table 6. Largest specimen examined 44.8 mm SL. Dorsal profile slightly concave on head, convex from nape to end of dorsal-fin base, approximately straight on caudal peduncle. Ventral profile convex from lower jaw to end of anal-fin base, nearly straight on caudal peduncle. Body deep, compressed, greatest body depth at level of pelvic-fin base. Eye positioned on dorsolateral portion of side of head. Snout blunt. Urogenital papilla cylindrical and short in males, pocket-shaped in females.

Tip of dorsal fin pointed in males, rounded to slightly pointed in females; tip of anal fin pointed in males, rounded in females. Tip of both dorsal and anal fins with filamentous rays in males, usually short, but sometimes reaching vertical through posterior portion of caudal fin. Caudal fin subtruncate in males, round in females. Pectoral fins elliptical. Posterior margin of pectoral fins reaching vertical through base of 7th or 8th anal-fin ray in males, and 3rd or 4th anal-fin ray in females. Tip of each pelvic fin reaching base of 3rd anal-fin ray in males and 2nd anal-fin ray in females. Pelvic-fin bases medially united. Dorsal-fin origin in vertical through base of 2nd anal-fin ray in males, and base of 3rd or 4th anal-fin ray in females; dorsal-fin origin between neural spines of vertebrae 7 and 9 in males, and neural spines of vertebrae 10 and 12 in females. Anal-fin origin between pleural ribs of vertebrae 7 and 8 in males, and pleural ribs of vertebrae 9 and 10 in females. Dorsal-fin rays 21-25 in males, 15-20 in females; anal-fin rays 22-24 in males, 19-23 in females; caudal-fin rays 23-26; pectoral-fin rays 12-13; pelvic-fin rays 6.

Frontal squamation E-patterned; E-scales overlapping medially; no scale anterior to G-scale; one supraorbital scale. Longitudinal series of scales 27-28; transverse series of scales 14; scale rows around caudal peduncle 16. Prominent contact organ on each scale of anteroventral portion of lateral surface of body in males. Small papillate contact organs on inner surface of three dorsalmost rays of pectoral fin in males. Cephalic neuromasts: supraorbital 16-18, parietal 3, anterior rostral 1, posterior rostral 1, infraorbital 2 + 20- 24, preorbital 3, otic 1, post-otic 2, supratemporal 1, median opercular 1, ventral opercular 2-3, preopercular 15-17, mandibular 12-14, lateral mandibular 7-9, paramandibular 1. One neuromast on center of each scale of lateral line. Two neuromasts on caudal-fin base.

Basihyal subtriangular, width about 70% of length; basihyal cartilage about 30% of total length of basihyal. Six branchiostegal rays. Second pharyngobranchial teeth 5-6. Gill-rakers on first branchial arch 4 + 13.

Vomerine teeth absent. Dermosphenotic present. Ventral process of posttemporal long. Total vertebrae 26- 28.

Coloration

Males. Side of body light bluish gray with white dots; 12-18 approximately straight faint gray bars, more conspicuous on caudal peduncle; sometimes venter pale pink. Opercular region light greenish golden. Iris light yellow, with dark gray bar. Dorsal fin dark bluish gray with white dots, and dark bluish gray distal border; dorsal-fin filaments black. Anal fin dark bluish gray, with white dots; subdistal zone reddish orange; blue spot on fin tip; black distal stripe; anal-fin filaments black. Caudal fin dark bluish gray with white spots, and metallic light blue bar on posterior edge of the fin. Pectoral fins hyaline. Pelvic fins reddish orange, with black tip.

Females. Sides of body light gray, with 11-18 dark gray bars; venter pale golden; 1-4 rounded black blotches on anterocentral portion of flank; 1-11 irregularly arranged rounded black blotches on caudal peduncle. Opercular region pale golden. Iris light yellow, with gray bar. Unpaired fins hyaline, with faint, longitudinally elongated gray spots; small, iridescent blue spot on posterior portion of anal fin close to caudal peduncle. Paired fins hyaline.

Distribution

Lower section of the rio Jaguaribe basin, and smaller coastal adjacent river basins between Mecejana, Estado do Ceará, and Areia Branca, Estado do Rio Grande do Norte, northeastern Brazil (Fig. 1).

Habitat

Temporary pools in the Caatinga.