Austrolebias carvalhoi

Wilson J. E. M. Costa, 2006, The South American annual killifish genus Austrolebias (Teleostei: Cyprinodontiformes: Rivulidae): phylogenetic relationships, descriptive morphology and taxonomic revision., Zootaxa 1213, pp. 1-162 : 90-92

Austrolebias carvalhoi (Myers)

(Fig. 35)

Cynolebias carvalhoi Myers, 1947: 19 ( type locality: highlands of the rio Iguassu [ Iguacu ] near Porto Uniao [ Uniao ] , Brazil; lectotype: MNRJ 5759 , designated by Costa (1998b).

Material examined

Brazil: Paraná: MNRJ 5759 , lectotype, male, 26.2 mm SL; MNRJ 5760 , 4 paralectotypes; Brazil: Estado do Paraná, pond close to rio Iguacu , about one mile from Porto Uniao ; G. S. Myers & A. L. Carvalho, 21- 25 Apr. 1944. UFRJ 4444 , 2; UFRJ 4445 , 2 (c&s); same locality ; W. J. E. M. Costa et al., 11 Sept. 1997.

Diagnosis

Differs from all other species of the genus by a unique male color pattern consisting of body side golden with eight to nine purplish gray bars. Other characters useful for recognizing the species are: no contact organs on male anal fin, pelvic-fin bases separated by small interspace, anal fin short in females, urogenital papilla not attached to anal fin, dorsal-fin origin anterior to anal-fin origin, dorsal-fin rays 21-22 in males, 16-18 in females; anal-fin rays 21-22 in males, 16-18 in females, and longitudinal series scales 27-29.

Description

Morphometric data appear in Table 6. Males and females similar in size, largest male examined 37.3 mm SL, largest female 38.1 mm SL. Dorsal profile slightly concave on head, convex from nape to end of dorsal-fin base, approximately straight on caudal peduncle; no distinctive adipose ridge on frontal region. Ventral profile convex from lower jaw to end of anal-fin base, nearly straight on caudal peduncle. Greatest body depth at level of pelvic-fin base. Body deep and moderately compressed. Snout blunt and jaws short.

Tip of both dorsal and anal fins rounded. Anteromedian rays of anal fin in females not lengthened; distal portion of anal fin thickened in females. Caudal fin rounded. Pectoral fins elliptical, short, posterior margin on vertical through anal-fin origin in males, through anus in females. Tip of each pelvic fin reaching base of 2nd anal-fin ray in males, and urogenital papilla in females. Pelvic-fin bases separated by small interspace. Urogenital papilla not attached to anal fin. Anal-fin origin on vertical through base 3rd dorsal-fin ray; dorsal-fin origin between neural spines of 10th and 11th vertebrae in males, between neural spines of 11th and 12th vertebrae in females. Anal-fin origin between pleural ribs of 9th and 10th vertebrae in males, between pleural ribs of 10th and 11th vertebrae in females. Dorsal-fin rays 21-22 in males, 16-18 in females; anal-fin rays 21-22 in males, 16-18 in females; caudal-fin rays 25-26; pectoral-fin rays 13; pelvic-fin rays 5.

Scales large and cycloid. Trunk and head entirely scaled, except ventral surface of head. Sometimes few scales extending over anal-fin base; no scales on dorsal-fin base; three rows of scales on caudal-fin base. Frontal squamation G-patterned; E-scales not overlapping medially; scales arranged in transverse pattern. Longitudinal series of scales 27-29, scales regularly arranged; transverse series of scales 13; scale rows around caudal peduncle 22. One contact organ on each scale of ventral portion of flank in males. Row of contact organs on three uppermost pectoral-fin rays in males. No contact organ on unpaired fins.

Cephalic neuromasts: supraorbital 17-18, parietal 1-2, anterior rostral 1, posterior rostral 1, infraorbital 3 + 20, preorbital 2, otic 3, post-otic 4-5, supratemporal 1, median opercular 1, ventral opercular 2, preopercular 20-23, mandibular 15-16, lateral mandibular 4.

Basihyal subtriangular, width about 80 % of length; basihyal cartilage long, about 65 % of total basihyal length, with pronounced lateral projection. Six branchiostegal rays. Urohyal deep. Three to five teeth on second pharyngobranchial. Gill-rakers on first branchial arch 3 + 9. Dermosphenotic ossification absent. Ventral process of posttemporal long. Total vertebrae 28-29.

Coloration

Males: sides of body golden, with 8-9 dark purplish gray bars, all bars wider than interspace, anterior bars slightly darker. Urogenital papilla dark gray. Opercular and infraorbital regions greenish golden; approximately rectangular dark gray infraorbital bar, subtriangular dark gray supraorbital bar. Iris orangish brown, with dark brown bar through center of eye. Unpaired and pelvic fins dark gray, with white dots on basal half of fins. Pectoral fins grayish hyaline.

Females: sides of body light yellowish brown, with round to slightly vertically elongated dark gray spots, darker on anterocentral portion of flanks; no distinctive spot on caudal peduncle. Opercular region pale greenish golden. Iris orangish brown with gray bar through center of eye. Infraorbital and supraorbital bars dark gray. Unpaired fins hyaline, with small gray spots on basal portion of anal fin; paired fins hyaline.

Distribution

Known only from the upper rio Iguaçú drainage, rio Paraná basin, southern Brazil (Fig. 8).