Austrolebias univentripinnis

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 : 101-104

Austrolebias univentripinnis Costa & Cheffe

(Fig. 39)

Austrolebias univentripinnis Costa & Cheffe, 2005: 44 ( type locality: temporary swamp about 200 m from rio Jaguarao drainage, laguna dos Patos system, Jaguarao , Rio Grande do Sul, Brazil, 22H 0268740 UTM 6402377; holotype: UFRJ 6081 ).

Material examined

Brazil: Rio Grande do Sul: Jaguarão, laguna dos Patos system: UFRJ 6081 , holotype, male, 34.9 mm SL; CIMC 8625 , 33 paratypes; UFRJ 6082 , 4 paratypes; UFRJ 6083 , 6 paratypes (c&s); Telho, temporary swamp about 200 m from rio Jaguarao drainage ; L. E. K. Lanés et al., 5 Sep. 2004. CIMC 8629 , 8 paratypes; rua 27 de Novembro, between the second and the third bridge, about 10 km from the road BR-116 ; same collectors and data as holotype. CIMC 8631 , 12 paratypes; arroio Telho floodplains ; same collectors and data as holotype. CIMC 8635 , 174 paratypes; Telho, about 21 km from the city of Jaguarao ; same collectors and data as holotype. CIMC 8642 , 41 paratypes; same locality and collectors as holotype, 6 Sep. 2004. UFRJ 6086 , 28 paratypes; same locality as CIMC 8635 ; L. E. K. Lanés et al., 24 Oct. 2004.

Diagnosis

Differs from all congeners except A. bellottii , A. apaii , and A. melanoorus , in having the entire urogenital papilla attached to the anal fin in males (vs. urogenital papilla free from the anal fin). Distinguished from A. bellottii and A. apaii in having fewer teeth on the second pharyngobranchial; from A. apaii in having fewer supraorbital neuromasts (17-18 vs. 20-24), fewer preopercular plus mandibular neuromasts (39-41 vs. 43-47), and anal-fin origin between pleural ribs of 7th and 9th vertebrae in males, between pleural ribs of 9th and11th vertebrae in females (vs. between pleural ribs of 5th and 7th vertebrae in males, between pleural ribs of 7th and 8th vertebrae in female); from A. bellottii by possessing a more slender body in males (body depth 36.6-39.8% SL vs. 40.1-46.1% SL) and by usually having more vertical rows of bright dots on the flanks in males (11-18 vs. 7-12); from A. melanoorus by possessing pelvic-fin bases united at about 75-90% of their medial margins (vs. about 10-25%), and distinct color patterns: flanks dark bluish gray, with vertical rows of bright greenish blue dots in males (vs. light bluish gray bars alternating with dark gray bars), unpaired fins with bright dots in males (vs. elongate light spots and bright lines parallel to fin rays), and females sometimes with one or two black spots on the center of the flanks, often black spots absent (vs. always 5-16 black spots); it may be also distinguished from A. melanoorus by possessing a single anterior rostral neuromast, except in one specimen with two (vs. always two anterior rostral neuromasts).

Description

Morphometric data appear in Table 7. Males larger than females, largest male examined 35.6 mm SL, largest female 32.2 mm SL. Dorsal profile slightly convex from snout 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. 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 3rd and 5th anal-fin rays in males, and between pelvic-fin base and urogenital papilla in females. Tip of each pelvic fin reaching between base of 3rd and 4th anal-fin ray. Medial pelvic-fin membranes about 75-90 % coalesced. Entire urogenital papilla attached to anal fin in males. Dorsal-fin origin on vertical slightly posterior to anal-fin origin in males, between base of 2nd and 4th anal-fin ray, and between neural spines of 7th and 9th vertebrae. In females, dorsal-fin origin on vertical just anterior to anal-fin origin, anal-fin origin on vertical through base of 2nd dorsal-fin ray, to dorsal-fin origin on vertical slightly posterior to anal-fin origin, on base of 2nd anal-fin ray; dorsal-fin origin between neural spines of 10th and 12th vertebrae. Anal-fin origin between pleural ribs of 7th and 9th vertebrae in males, between pleural ribs of 9th and 11th vertebrae in females. Dorsalfin rays 23-28 in males, 20-23 in females; anal-fin rays 26-30 in males, 22-26 in females; caudal-fin rays 23-25; pectoral-fin rays 11-12; pelvic-fin rays 5.

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 G-patterned, except in one specimen, H- patterned; E-scales not overlapping medially; scales arranged in transverse pattern. Longitudinal series of scales 28-30; transverse series of scales 13-14; scale rows around caudal peduncle 16. Four to six minute contact organs on scales of ventral portion of male flanks. Row of minute contact organs on uppermost pectoral-fin ray in males. No contact organ on unpaired fins.

Cephalic neuromasts: supraorbital 17-18, parietal 3, anterior rostral 1 except one specimen with 2, posterior rostral 1, infraorbital 2 + 22-25, preorbital 3, otic 3, post-otic 3-4, supratemporal 1, median opercular 1, ventral opercular 2, preopercular 24-26, mandibular 15, lateral mandibular 5.

Basihyal nearly triangular, width about 65% of length; basihyal cartilage long, about 65% of total basihyal length, with pronounced lateral projection. Six branchiostegal rays. Six to eight teeth on second pharyngobranchial. Gill-rakers on first branchial arch 3-4 + 11-12. Two, one or no dermosphenotic ossifications. Ventral process of posttemporal long. Total vertebrae 29-31.

Coloration

Males: sides of body dark greenish gray, with 11-18 vertical rows of bright greenish blue dots, often forming lines; venter yellowish white. Sides of head dark greenish gray to bright blue on opercular and infraorbital regions; approximately rectangular pale gray infraorbital bar; subtriangular dark gray supraorbital bar. Iris dark yellow, with dark brown bar through center of eye. Dorsal fin dark bluish green to pale pink on anterodistal portion, with light green dots; posterodistal black margin. Anal fin dark bluish green to light blue on distal portion, with subbasal row of small light green spots; preserved specimens with black distal stripe. Caudal fin dark bluish green, with greenish blue dots; posterior portion hyaline with green iridescence. Pelvic fins dark bluish green, with black tip. Pectoral fins hyaline, with dark greenish blue ventral margin.

Females: sides of body light yellowish brown, with vertically elongate dark gray spots, often vertically arranged, sometimes forming bars; sometimes one or two black spots on anterocentral portion of flank; venter pale yellow. Opercular region pale greenish blue. Pale gray supraorbital and infraorbital bars. Iris light yellow, with gray bar through center of eye. Fins hyaline; dorsal and anal fins with dark gray small spots on basal region.

Distribution

Rio Jaguarão drainage, lagoa Mirim system, southern Brazil (Fig. 11).