Simpsonichthys de Carvalho,

Wilson J. E. M. Costa, 2006, Three new species of seasonal killifishes of the Simpsonichthys antenori species group (Teleostei: Cyprinodontiformes: Rivulidae) from the rio São Francisco basin, Brazil., Zootaxa 1306, pp. 25-39: 37-38

publication ID

z01306p025

publication LSID

lsid:zoobank.org:pub:21A62C97-8BE0-4382-BE2F-D1B605AA6F19

persistent identifier

http://treatment.plazi.org/id/7F1556EF-B786-A086-4DA7-CBF8BB8D1272

treatment provided by

Thomas

scientific name

Simpsonichthys de Carvalho
status

 

[[ Genus Simpsonichthys de Carvalho  ZBK  ]]

Discussion

The present study reveals a great diversity of species of the Simpsonichthys antenori group  in the upper sections of eastern tributaries of the middle rio São Francisco in serra do Espinhaço, including rio Verde Grande, rio Carnaiba de Dentro, and rio Paramirim. The species inhabiting this area, S. janaubensis  , S. mediopapillatus  , S. ghisolfii  ZBK  , and S. macaubensis  , were not found in other places during recent intensive field studies in the region, suggesting that they are geographically restricted to short sections of the river drainages. In the lower portions of the rio Verde Grande and rio Carnaiba de Dentro, they are replaced by S. flagellatus  ZBK  , a species widespread throughout the rio São Francisco basin (Fig. 3). This suggests that species endemic to the upper sections are effectively isolated from congeners inhabiting the lower sections.

The species endemic to upper tributaries of the rio São Francisco draining the serra do Espinhaço do not constitute a monophyletic assemblage. Among them, S. janaubensis  is a member of a clade defined by Costa (2006), including S. flavicaudatus  and S. flagellatus  ZBK  , which are diagnosed by the derived color patterns of the anal fin in males: anterior portion pink, posterior portion yellow; bright blue or white dots on posterior part of fin, but not on anterior part; and presence of a light gray distal stripe. Simpsonichthys janaubensis  is therefore considered more closely related to S. flavicaudatus  and S. flagellatus  ZBK  than to other species from the Serra do Espinhaço (i. e., S. mediopapillatus  , S. ghisolfii  ZBK  , and S. macaubensis  ). On the other hand, S. mediopapillatus  and S. ghisolfii  ZBK  are sister species, since both share an apomorphic long urogenital papilla in males, a condition not found elsewhere among species of Hypsolebias  (Costa, 2006).

Key to species of the S. antenori group 

1a. Dorsal and anal-fin filaments reaching between central and posterior portion of caudal fin, or surpassing it in males; unpaired fins pink, yellow or orange in males .................................................................................................................................2

1b. Dorsal and anal-fin filaments short, reaching caudal-fin base; unpaired fins dark bluish gray in males................................................................................. S. antenori 

2a(1a). Filamentous rays of dorsal and anal fins of moderate length in males, tip of each fin reaching posterior portion of caudal fin............................................................3

2b(1a). Filamentous rays of dorsal and anal fins rather long in males, tip of each fin extending beyond posterior margin of caudal fin...................................................5

3a(2a). Urogenital papilla long in males, notably conspicuous in lateral view (Fig. 6C)............................ 4

3b(2a). Urogenital papilla short in males, almost imperceptible in lateral view................... .......................................................................................................... S. macaubensis 

4a(3a). No contact organs on flank in males; a median neuromast on posterior rostral series (Fig. 6B)........................................................................... S. mediopapillatus 

4b(3a). Contact organs on anteroventral portion of flank in males; no median neuromast on posterior rostral series......................................................................... S. ghisolfii  ZBK 

5a(2b). Six pelvic-fin rays; flanks with gray bars and few or no light dots in males; anal fin pink anteriorly and yellow posteriorly, with gray distal stripe in males................6

5b(2b). Seven pelvic-fin rays; flanks of males without bars or sometimes hardly visible only in preserved specimens, and with numerous light dots; anal fin yellow, with orange subdistal stripe and black distal stripe in males.............................. S. igneus  ZBK 

6a(5a). Pectoral-fin contact organs pronounced in males; dorsal profile of head conspicuously concave; anterobasal portion of dorsal fin with short light stripes alternating with dark gray to black areas..................................................................................7

6b(5a). Pectoral-fin contact organs minute in males; dorsal profile of head nearly straight; anterobasal portion of dorsal fin with small light spots, sometimes slightly elongated ................................................................................................. S. flavicaudatus 

7a(6a). Elongated light blue spots restricted to anterior portion of dorsal-fin base in males; anal-fin base in males 39.0-45.2 % SL; body depth in combined sexes 37.0-42.7%; caudal-peduncle depth in combined sexes 13.4-16.6%............................. S. flagellatus  ZBK 

7b(6a). Elongated light blue spots along entire dorsal-fin base in males; anal-fin base in males 34.4-38.4 % SL; body depth in combined sexes 30.7-38.4%; caudal-peduncle depth in combined sexes 11.7-14.3% .......................................... S. janaubensis