Simpsonichthys mediopapillatus

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 : 102-103

Simpsonichthys mediopapillatus Costa, 2006

(Figs. 64)

Simpsonichthys ghisolfii non S. ghisolfii Costa, Cyrino & Nielsen; Costa, 2003: 41 (misidentification).

Simpsonichthys mediopapillatus Costa, 2006b: 30 ( type locality: temporary pool 8 km S of Pindai , rio Sao Domingos drainage, a tributary to the Rio Verde Pequeno, itself a tributary of rio Verde Grande, rio Sao Francisco basin , 14°33’36.7”S 42°42’9.8”W, altitude 628 m, Estado da Bahia, Brazil; holotype: UFRJ 5406 ).

Material examined

Brazil: Estado da Bahia, rio São Francisco basin: UFRJ 5406 , holotype, male, 40.3 mm SL; UFRJ 5408 , 9 paratypes; UFRJ 5407 , 3 paratypes (c&s); Brazil: Estado da Bahia, temporary pool 8 km S of Pindai , rio Sao Domingos drainage, a tributary to the Rio Verde Pequeno, itself a tributary of rio Verde Grande, rio Sao Francisco basin , 14°33’36.7”S 42°42’9.8”W, altitude 628 m; W. J. E. M. Costa, C. P. Bove & B. B. Costa, 23 Jan. 2002. UFRJ 6064 , 12 paratypes; UFRJ 6074 , 4 paratypes; MCP 40139 , 3 paratypes; same locality and collectors, 15- 16 Jan. 2005.

Diagnosis

Distinguished from all other congeners of the S. antenori group in having a median neuromast on posterior rostral series (vs. median rostral neuromast absent). Similar to S. ghisolfii , and distinguished from the other species of the S. antenori group, by possessing a long (vs. short) urogenital papilla in males, zigzag shaped bars on caudal peduncle in males (vs. bars straight or slightly curved), and a distinctive narrow subdistal bright yellowish orange stripe on anal fin in males (vs. never a similar color pattern). Also distinguished from S. ghisolfii by the absence of contact organs on the flank of males (vs. minute contact organs present on posterior border of scales of the anteroventral portion of flank).

Description

Morphometric data appear in Table 6. Largest specimen examined 43.4 mm SL. Dorsal profile nearly straight on head, convex from nape to end of dorsal-fin base, nearly straight on caudal peduncle. Ventral profile convex from lower jaw to end of anal-fin base, approximately straight on caudal peduncle. Eye positioned on dorsolateral portion of side of head. Snout blunt. Body deep, compressed, greatest body depth at level of pelvic-fin bases. Urogenital papilla cylindrical and long in males, pocket-shaped in females.

Tip of dorsal fin pointed in males, slightly pointed in females; tip of anal fin pointed in males, rounded in females. Tips of dorsal and anal fins with filamentous rays in males, tips reaching posterior portion of caudal fin. Caudal fin subtruncate in males, round in females. Pectoral fins elliptical. Posterior margin of pectoral fins reaching to vertical between base of 6th and 8th anal-fin rays in males, and between urogenital papilla and base of 1st anal-fin ray in females. Tip of each pelvic fin reaching to base of 3rd or 4th anal-fin ray in males and between urogenital papilla and base of 1st anal-fin ray in females. Pelvic-fin bases medially united. Dorsal-fin origin on vertical between base of 3rd and 4th anal-fin rays in males, and between base of 4th and 6th anal-fin rays in females; dorsal-fin origin between neural spines of vertebrae 7 and 8 in males, and neural spines of vertebrae 11 and 12 in females. Anal-fin origin between pleural ribs of vertebrae 7 and 8 in males, and pleural ribs of vertebrae 9 and 11 in females. Dorsal-fin rays 20-23 in males, 15-17 in females; anal-fin rays 21-23 in males, 19-21 in females; caudal-fin rays 22-24; pectoral-fin rays 12; pelvic-fin rays 6.

Frontal squamation E-patterned; E-scales overlapping medially; no scales anterior to H-scale; two or three supraorbital scales. Longitudinal series of scales 28-30; transverse series of scales 12-13; scale rows around caudal peduncle 16. No contact organs on scales. Small papillate contact organs on inner surface of three dorsalmost rays of pectoral fin in males.

Cephalic neuromasts: supraorbital 14-17, parietal 2-3, anterior rostral 1, posterior rostral with one lateral neuromast and middle neuromast, infraorbital 2 + 22-24, preorbital 3, otic 2, post-otic 3, supratemporal 1, median opercular 1, ventral opercular 1, preopercular 16-18, mandibular 13-15, lateral mandibular 4, paramandibular1. One neuromast on each scale of lateral line. Two neuromasts on caudal-fin base.

Basihyal subtriangular, width about 80% of length; basihyal cartilage about 25% of total length of basihyal. Six branchiostegal rays. Second pharyngobranchial teeth 9. Gill-rakers on first branchial arch 4 + 11. Vomerine teeth absent. Dermosphenotic absent. Ventral process of posttemporal long. Total vertebrae 29- 30.

Coloration

Males. Sides of body light bluish gray, with white dots and 13-19 approximately straight and wide gray bars, more conspicuous and zigzag shaped on caudal peduncle. Dorsum pale brown. Venter light gray. Opercular region pale greenish blue. Iris light yellow, with dark purplish gray bar through center of eye. Dorsal fin greenish yellow, dark purplish pink on distal portion, with white dots; dorsal-fin filaments dark purple. Anal fin greenish yellow, with bluish white dots; subdistal zone bright yellowish orange, to light blue near fin tip; distal zone black; anal-fin filaments black. Caudal fin dark greenish yellow, with bluish white dots; broad bright blue zone on posterior margin of fin. Pectoral fins hyaline. Pelvic fins yellow, with black tips.

Females. Sides of body light gray, with 13-16 dark gray bars; venter pale golden; 1-3 rounded black blotches on anterocentral portion of flank; 1-7 irregularly arranged rounded black blotches on caudal peduncle. Dorsum pale brown. Venter light gray. Opercular region pale greenish golden. Iris light yellow, with gray bar through center of eye. 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

Rio Verde Grande drainage, rio São Francisco basin, Estado da Bahia, Brazil (Fig. 1)

Habitat

Temporary pools in the Caatinga.