Leptolebias marmoratus, (LADIGES, 1934)

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 : 156

LEPTOLEBIAS MARMORATUS ( LADIGES, 1934)

Cynopoecilus marmoratus Ladiges, 1934: 74 [type locality: Rio de Janeiro (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) Brazil; neotype, MCP 28604, from temporary pool, Vila de Cava, Nova Iguaçu, Estado do Rio de Janeiro, Brazil, 22°39′30.0′S, 43°25′45.7′W, designated by Costa, 2002a].

Cynopoecilus sicheleri Miranda-Ribeiro, 1939: 363 (type locality: slow-moving rivers at the base of Petrópolis hill, Estado do Rio de Janeiro, Brazil; syntypes, MNRJ 4739 ).

Cynolebias zingiberinus Myers, 1942: 108 [type locality: isolated depression only filled with water during the rainy season, along the base of the Petrópolis hill (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), Estado do Rio de Janeiro, Brazil; holotype, CAS (SU) 36523).

Material examined: Brazil, Rio de Janeiro: MCP 28604, neotype, male, 23.3-mm SL; UFRJ 5404, 1; UFRJ 5355, 24; UFRJ 5403, one; UFRJ 5356, 4 (c&s); UFRJ 5220, 6 (c&s); temporary pool, Vila de Cava , Nova Iguaçu ; CAS ( SU) 36523, holotype of C. zingiberinus ; CAS ( SU) 36524, ten paratypes of C. zingiberinus ; MNRJ 4739 , eight syntypes of C. sicheleri ; base of serra de Petrópolis .

Diagnosis: Distinguished from all congeners by having asymmetrically lanceolate caudal fin, with convex dorsal profile and straight ventral profile (vs. caudal fin symmetrical), urogenital papilla attached to anal fin in males (vs. urogenital papilla free), thickened tissue on anterior portion of anal fin in males (vs. never thickened), white stripe with narrow black border on ventral edge of caudal fin in males (vs. no similar colour pattern), and posterior half of flank dark brown with horizontal rows of yellow spots, coalesced to form stripe on lateral midline of caudal peduncle in males (vs. no similar colour pattern).

Remarks: Redescribed by Costa (2002b).

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

Habitat and conservation: Between 1934 and 1944, L. marmoratus was known to occur in temporary pools within the forests of the Estrela river basin (A. L. Carvalho and H. S. Lopez, pers. comm.). The forest was later abruptly removed, and no specimen of L. marmoratus was collected in the type locality region after 1944. The species was rediscovered 56 years later, in a small forest in the margins of the Iguaçu River near Cava, Nova Iguaçu. The area is not formally protected, and thus L. marmoratus is considered highly threatened with extinction.

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.