Austrolebias adloffi

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 : 126-129

Austrolebias adloffi (Ahl)

(Fig. 48)

Cynolebias adloffi Ahl, 1922: 224 ( type locality: Porto Alegre [Estado do Rio Grande do Sul, Brazil]; lectotype: ZMB 20651 , designated in Paepke & Seegers, 1986).

Material examined

Brazil: Rio Grande do Sul: laguna dos Patos system: MZUSP 38376 , 9; Sao Leopoldo, bairro Santos Dumont, rio dos Sinos basin ; T. P. Lacerda, 20 Dec. 1979. MZUSP 38411 , 8; Porto Alegre ; unknown collector, Jun. 1986. MCP 10288 , 12; Canoas, distrito de Mato Grande, rio dos Sinos basin ; C. A. Lucena, J. J. Bertoletti & L. R. Malabarba, 17 Oct. 1984. MCP 10933 , 30 (3 c&s); Gravatai , flooded area in distrito de Alvorada, rio Gravatai basin ; L. R. Malabarba, R. Reis, P. Azevedo and L. Bergmann, 9 Jul. 1986. MNRJ 11393 , 2; Sao Leopoldo, road BR-116 ; T. Lacerda, 18 Oct. 1967. CIMC 3521 , 32; UFRJ 6181 , 5; UFRJ 6182 , 3 (c&s); swamp close to the road RS-118, about 500 m from the road BR-290, Gravatai ; G. Maurício, 24 Aug. 2000.

Diagnosis

Distinguished from the remaining species of the A. adloffi group by the following combination of features: dorsal-fin origin posterior to anal-fin origin in both males and females, 26-30 anal-fin rays in males and 23-26 in females, 19-22 caudal-fin rays, maximum body depth 44.2 % SL in older males, 3-4 teeth on second pharyngobranchial in larger specimens, 27-30 vertebrae, posterior border of the dorsal and anal fins black in males, a black bar on parietal series of neuromasts, dorsal and anal-fin bases with elongated white spots, all flank bars narrower than interspace.

Description

Morphometric data appear in Table 9. Males larger than females, largest male examined 45.9 mm SL, largest female 37.3 mm SL. Dorsal profile convex from snout to end of dorsal-fin base, approximately straight on caudal peduncle; pronounced adipose ridge on frontal region of head in males. 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 compressed. Snout blunt and jaws short.

Tip of both dorsal and anal fins rounded. Anteromedian rays of anal fin of females lengthened, anal fin shape nearly triangular; distal portion of anal fin thickened in females. Caudal fin rounded. Pectoral fins elliptical, posterior margin on vertical between base of 5th and 8th anal-fin rays in males, and between urogenital papilla and base of 2nd anal-fin ray in females. Tip of each pelvic fin reaching between base of 3rd and 4th anal-fin rays. Medial pelvic-fin membranes 50-80 % coalesced. Urogenital papilla not attached to anal fin. Dorsal-fin origin on vertical through base of 4th or 5th anal-fin ray in males, through base of 2nd or 3rd anal-fin ray in females, between neural spines of 7th and 8th vertebrae in males, between neural spines of 9th and 10th vertebrae in females. Anal-fin origin between pleural ribs of 6th and 7th vertebrae in males, between pleural ribs of 8th and 9th vertebrae in females. Dorsal-fin rays 21-25 in males, 18-22 in females; anal-fin rays 23-30 in males, 23-26 in females; caudal-fin rays 20-22; pectoral-fin rays 11-12; pelvicfin rays 5-6.

Scales large and cycloid. Trunk and head entirely scaled, except ventral surface of head. One row of scales on anal-fin base, no scales on dorsal-fin base, and three rows of scales on caudal-fin base. Frontal squamation F-patterned; E-scales slightly overlapping medially; scales arranged in transverse pattern. Longitudinal series of scales 26-28, scales regularly arranged; transverse series of scales 12-14; scale rows around caudal peduncle 16. Three to seven minute contact organs on each scale of ventral portion of flank in males. Rows of minute contact organs on three or four uppermost pectoral-fin rays in males. No contact organ on anal, dorsal and caudal fins.

Cephalic neuromasts: supraorbital 16-19, parietal 3-4, anterior rostral 1, posterior rostral 1, infraorbital 2 + 19-25, preorbital 2, otic 2, post-otic 3-6, supratemporal 1, median opercular 1, ventral opercular 2-3, preopercular plus mandibular 31-38, lateral mandibular 6-7.

Basihyal nearly triangular, width about 65 % of length; basihyal cartilage long, about 55-60 % of total basihyal length, with pronounced lateral projection. Six branchiostegal rays. Two to five teeth on second pharyngobranchial. Gill-rakers on first branchial arch 3-4 + 11. Dermosphenotic ossification absent. Ventral process of posttemporal long. Total vertebrae 27-30.

Coloration

Males: sides of body light blue, with 7-14 black bars; bars narrow, interspace about 2-4 times wider than bars; often an 8-shaped black spot on posterior part of caudal peduncle. Urogenital papilla gray. Sides of head light bluish green to blue on opercular and infraorbital regions; black infraorbital bar, wider close to eye, gradually narrowing ventrally; elongate triangular black supraorbital bar, with distinctive narrow extension over neuromast parietal series. Iris dark yellow, with dark brown bar through center of eye. Dorsal and anal fins dark gray, posterior border black, with light blue spots, elongated on fin bases. Caudal fin dark gray, with light blue spots on basal portion. Pelvic fins dark bluish gray. Pectoral fins hyaline, with bluish black ventral margin.

Females: sides of body light yellowish brown, with pale gray bars or vertical rows of elongate dark gray spots; venter pale golden; no black spot on anterocentral portion of flank; two black spots vertically arranged on posterior portion of caudal peduncle, often coalesced to form an 8-shaped spot. Opercular region pale greenish blue. Iris light yellow, with gray bar through center of eye. Infraorbital and supraorbital bars dark gray. Unpaired fins hyaline, with gray spots; paired fins hyaline.

Distribution

Lower rio Jacuí - Guaíba basin, including lower rio Gravataí, rio dos Sinos and rio Caí drainages, laguna dos Patos system, Rio Grande do Sul, southern Brazil (Fig. 52).