Austrolebias wolterstorffi, Wilson J. E. M. Costa, 2006

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 : 48-51

Austrolebias wolterstorffi (Ahl), new combination

(Fig. 19)

Cynolebias bellottii non C. bellottii Steindachner; Adloff, 1922: 221 ( misidentification of specimens from Porto Alegre , Brazil ).

Cynolebias wolterstorffi Ahl, 1924: 359 ( type locality: Porto Alegre [Rio Grande do Sul, Brazil]; lectotype: ZMH H65 , designated by Paepke & Seegers, 1986).

Cynolebias schreitmuelleri Ahl, 1934: 308 ( type locality: Rio de Janeiro [incorrect: aquarium import of unknown origin] ; syntypes lost [Paepke & Seegers, 1986]; neotype: UFRJ 6218 [herein designated] .

Cynolebias haerteli Schreitmüller, 1937: 11 ( nomen nudum).

Material examined

Brazil: Rio Grande do Sul: laguna dos Patos system: UFRJ 6218 , male neotype of C. schreitmuelleri , 68.8 mm SL; UFRJ 4969 , 3; Porto Alegre ; unknown collector. MCP 15038 , 1; Cachoeirinha, swamp near the road BR-290, km 82, rio Gravatai floodplains ; L. R. Malabarba, J. Pezzi & E. Vidal, 6 Sep. 1991. MCP 8340 , 7 of 9; rio Cai floodplains, rio Jacui basin, road Tabai-Canoas , km 427, Triunfo ; L. R. Malabarba, R. Reis, P. Azevedo & L. Bergmann, 9 July 1986. MNRJ 11404 , 2; temporary swamp near the road BR-116, Sao Leopoldo ; T. Lacerda, 18 Oct. 1967. CIMC 3520 , 8; temporary swamp at rio Gravatai floodplains, near the road RS-118 and about 500 m from the road BR-290, Gravatai ; G. Maurício, 24 Aug. 2000. UFRJ 4011 , 4; temporary pool in Pontal da Barra, praia de Laranjal, canal de Sao Goncalo floodplains, Pelotas ; M. Cheffe, G. Mauricio & L. Matheus, 22 Aug. 1991. UFRJ 4013 , idem ; M. Cheffe & G. Mauricio, 16 Aug. 1993. CIMC 3430 , 4; idem ; M. Cheffe & G. Mauricio, 28 Sep. 1999. CIMC 3442 , 8; idem ; M. Cheffe & G. Mauricio, 23 Oct. 1999. CIMC 3589 , 1; temporary swamp in Sao Caetano, 20 km NE of Sao Jose do Norte ; G. Mauricio & J. Mahler Jr., 25 Oct. 2000. CIMC 3539 , 2; swamp close to the road BR-471, Vila do Povo Novo, Rio Grande ; M. Cheffe & G. Mauricio, 30 Aug. 2000. Uruguay: Treinta y Tres: CTL 1520 , 5; temporary swamp close to arroyo Yerbal , 33°13.30’S 54°23.93’W; P. Laurino et al., 28 Aug. 2004. Rocha: UFRJ 6231 , 4; UFRJ 6232 , 2 (c&s); CTL 1392 , 9; temporary swamp near canal Andreoni , 33°55.21’S 53°32.61’W; P. Laurino et al., 27 Aug. 2004.

Diagnosis

Distinguished from the remaining species of the A. elongatus group in having 31-35 scales on the longitudinal series (vs. about 50-75), minute contact organs on uppermost pectoral-fin ray in males (prominent contact organs on most pectoral-fin rays), and seven branchiostegal rays (vs. six).

Description

Morphometric data appear in Table 3. Males larger than females, largest male examined 77.5 mm SL, largest female 57.3 mm SL. Dorsal profile weakly convex from snout 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 moderately deep, slightly compressed. Snout slightly pointed and jaws moderately elongated.

Tip of both dorsal and anal fin rounded. Anteromedian rays of anal fin of female not lengthened; distal portion of anal fin thickened in female. Caudal fin rounded. Pectoral fins elliptical, posterior margin on vertical between base of 3rd and 6th anal-fin rays in males, between urogenital papilla and base of 2nd anal-fin ray in females. Tip of each pelvic fin reaching between base of 2nd and 4th anal-fin rays in males, between urogenital papilla and base of 1st anal-fin ray in females. Pelvic-fin bases separated by small interspace. Urogenital papilla not attached to anal fin. Dorsal-fin origin on vertical between base of 3rd and 6th anal-fin rays in males, between base of 4th and 6th anal-fin rays in females; dorsal-fin origin between neural spines of 12th and 15th vertebrae in males, between neural spines of 14th and 17th vertebrae in females. Anal-fin origin between pleural ribs of 9th and 12th vertebrae in males, between pleural ribs of 11th and 14th vertebrae in females. Dorsal-fin rays 18-23 in males, 15-21 in females; anal-fin rays 23-28 in males, 23-27 in females; caudal-fin rays 29-33; pectoral-fin rays 13-14; pelvicfin rays 5-6.

Scales large and cycloid. Trunk scaled, except region adjacent to dorsal and anal fins. Head scaled, except anterior 3/4 of frontal region and entire ventral surface. Three rows of scales on caudal-fin base; no scales on dorsal and anal fins. Frontal scales small, restricted to posterior frontal portion, without clear arrangement pattern; E-scales not overlapping medially. Longitudinal series of scales 31-35, scales regularly arranged; transverse series of scales 12-14; scale rows around caudal peduncle 22-26. One prominent contact organ on each scale of anteroventral portion of flank and opercle in males. Row of minute contact organs on uppermost pectoral-fin ray in males. No contact organ on dorsal, anal and caudal-fin rays.

Cephalic neuromasts: supraorbital 26-32, parietal 3-4, anterior rostral 2-3, posterior rostral 2-3, infraorbital 3-5 + 27-31, preorbital 2-3, otic 5-8, post-otic 6-8, supratemporal 2-3, median opercular 1, ventral opercular 2-4, preopercular plus mandibular 45-56, lateral mandibular 7-8.

Basihyal subtriangular, its width about 65 % of length; basihyal cartilage short, about 25 % of total basihyal length, without lateral projections. Seven branchiostegal rays. Teeth absent from second pharyngobranchial. Gill-rakers on first branchial arch 2 + 9. Dermosphenotic ossification absent. Ventral process of posttemporal vestigial or absent. Total vertebrae 32-34.

Coloration

Males: sides of body dark purplish brown, with white dots. Urogenital papilla dark gray. Opercular and infraorbital regions pale greenish blue; approximately rectangular, elongate black infraorbital bar; faint gray supraorbital spot. Iris dark orange, with black bar through center of eye. Unpaired fins dark gray with white dots; pink iridescence on dorsal fin, and blue iridescence on anal fin and ventral portion of caudal fin. Pelvic fins dark bluish gray. Pectoral fins hyaline.

Females: sides of body light pinkish brown, with small dark gray irregularly coalesced spots; rarely darker spot on anterocentral portion of each flank. Opercular region pale golden. Iris yellow, with dark gray bar through center of eye. Faint infraorbital gray bar; no supraorbital spot. Unpaired fins pale yellow, with small dark gray spots transversely coalesced; paired fins hyaline.

Distribution

Laguna dos Patos system, southern Brazil and eastern Uruguay (Fig. 20).

Remarks

Cynolebias schreitmuelleri was described by Ahl (1934) based on three specimens, 43-47 mm total length, obtained from an aquarium fish shipment supposedly from Rio de Janeiro. The original description is poor and does not include illustrations. Unfortunately, the three syntypes are lost (Paepke and Seegers, 1986). Ahl (1934) placed this species close to A. wolterstorffi , a species also described by him 10 years before, in his key for identification. Lazara (1984) listed C. schreitmuelleri as a synonym of A. wolterstorffi without justification. According to Ahl’s key, C. schreitmuelleri differs from A. wolterstorffi in having fewer scales on the longitudinal series (35-36, vs. 40-43), which would make synonymy of C. schreitmuelleri and A. wolterstorffi unacceptable. However, data on longitudinal scale counts presented by Ahl for A. wolterstorffi are equivocal. As demonstrated in the present revision, there are only 31-35 longitudinal scales in specimens of A. wolterstorffi over the entire geographic range of the species. In fact, all data provided by Ahl (1934) for C. schreitmuelleri are within the range of variation found for A. wolterstorffi in the present study.

During the past 20 years, annual fish habitats have been intensively sampled in Rio de Janeiro state, and no fish similar to C. schreitmuelleri has ever been reported from this region. During the 1930’s, aquarium fish shipments (with indicated killifish species) from Rio de Janeiro ( Leptolebias marmoratus Ladiges), Porto Alegre ( A. wolterstorffi , A. adloffi and Cynopoecilus melanotaenia (Regan)), and Buenos Aires ( A. bellottii , A. elongatus , and A. nigripinnis ) were common, as reported in the aquarium literature from that time. Among the species known today to be endemic to these areas, the only one fitting the data provided in the original description of C. schreitmuelleri is A. wolterstorffi . In order to resolve this nomenclatural problem, a neotype for C. schreitmuelleri is herein designated. The neotype is from the type locality of A. wolterstorffi , making C. schreitmuelleri an unequivocal synonym.