Leptolebias opalescens, (MYERS, 1942)

Costa, Wilson J. E. M., 2008, Monophyly and taxonomy of the Neotropical seasonal killifish genus Leptolebias (Teleostei: Aplocheiloidei: Rivulidae), with the description of a new genus, Zoological Journal of the Linnean Society 153 (1), pp. 147-160 : 154-155

LEPTOLEBIAS OPALESCENS ( MYERS, 1942)

Cynopoecilus fluminensis Faria & Muller, 1937: 99 [name suppressed for purposes of priority, and placed on Official Index & Opinion 1762; type locality: Estado do Rio de Janeiro, in small ponds in shady places near streams, containing abundant water during the winter, but drying out completely in the dry season (temporary pools close to the old road Rio-Petrópolis, near Imbariê, Município de Duque de Caxias, Estrela river drainage, Guanabara bay basin, Estado do Rio de Janeiro, about 22°37′S, 43°12′W); syntypes lost).

Cynolebias opalescens Myers, 1942: 107 [type locality: water holes or ponds along base of the Serra do Petropolis (serra de Petrópolis) (temporary pools close to the old road Rio-Petrópolis, near Imbariê, Município de Duque de Caxias , Estrela river drainage, Guanabara bay basin, about 22°37′S, 43°12′W), State of Rio de Janeiro, Brazil; holotype, CAS (SU) 36521].

Cynolebias nanus Cruz & Peixoto, 1983: 90 [type locality: right side of the road between the villages of Cava and Tinguá , 22°38′S, 43°25′W, approximately 8 km from the first village ( Iguaçú river drainage, Guanabara bay basin), Município de Nova Iguaçu, Estado do Rio de Janeiro ( Brazil); holotype, MNRJ 10621 ).

Material examined: Brazil, Rio de Janeiro: CAS ( SU) 36522, six paratypes ; MNRJ 11301 , 3 ; base of serra de Petrópolis ; MNRJ 10621 , holotype of C. nanus , 20.3-mm SL , MNRJ 10622 , 1 , MZUSP 25229 /30, two paratypes of C. nanus ; road between Cava and Tinguá, about 8 km from Cava, Nova Iguaçu .

Diagnosis: Distinguished from all congeners, except L. citrinipinnis , in having dorsal-fin origin in vertical between base of seventh and ninth anal-fin rays (vs. between base of second and sixth anal-fin rays). It differs from L. citrinipinnis by having caudal fin lanceolate (vs. elliptical), dark-red stripe on distal margin of dorsal and anal fins, and dorsal and ventral margin of caudal fin in males (vs. reddish brown pigmentation diffuse).

Remarks: Redescribed by Costa & Lacerda (1988).

Distribution: Estrela and Iguaçu river basins, both draining into Guanabara bay, Rio de Janeiro state, south-eastern Brazil ( Fig. 5 ).

Habitat and conservation: Not collected since 1981, so possibly extinct. Its area of occurrence was formerly occupied by dense rainforest, but is now highly urbanized. Leptolebias opalescens was collected both in open vegetation and in forest borders, sometimes sympatric to L. splendens and L. marmoratus .

Figures

Figure 5. Geographical distribution of Leptolebias in Rio de Janeiro state, south-eastern Brazil: 1, L. marmoratus, L. splendens, and L. opalescens; 2, L. marmoratus and L. opalescens; 3, L. splendens; 4, L. citrinipinnis.