Cyprinodontiformes: Rivulidae: Cynolebiatinae
Cynolebias gibbus Costa, 2001
The specific epithet ‘gibbus’ is Latin and means humpbacked, an allusion to the prominent convexity (hump) of the dorsal profile above the pectoral base in adults; an adjective. The gender is masculine.
male, max. SL 98.1 mm (UFRJ 5027); female max. SL 84.7 mm (UFRJ 4797, Costa 2001)
Similar to C. attenuatus Costa, 2001; body depth 29.7-33.6% SL, caudal peduncle depth 15.3-17.2% SL, head depth 31.0-33.1% SL, pectoral fin length 22.8-26.7% SL, anal fin base length 28.6-34.5% SL in males (Costa, 2001).
Figure 1. Cynolebias gibbus; female, lateral view, immediately after catch, specimen collected 2008-02-07, E-BR 42-08, SW of Sitio do Mato, Estado do Bahia, NE Brazil.
‘Catalog of Fishes’ synonyms
Since this species occur in isolated ephemeral pools they are sensitive to changes in the geologic hydrosystem. Intensive water usage for agricultural irrigation purpose is a ubiquitous and serious threat.
IUCN Red List not evaluated.
Occurs syntop with Simpsonichthys adornatus Costa, 2000 (ME, 2008, pers. obs.) and Cynolebias gilbertoi Costa, 1998 (Nielson, 2008, pers. com.) in E-BR 42-08.
E-BR 42-08, GPS: 434m asl, S 13º 05.169', W 43º 30.545', pond on right side of the BA161 towards Sitio do Mato (towards east), ca. 6 km after the access to Malhada Alta (BA576), central southern Bahia state, Brazil (ME, 2008, pers. obs.).
Endemic to the Rio Sao Francisco floodplains; 9.5 km N of Sitio do Mato, central southern Bahia state, Brazil (Costa, 2001).
Dimorphism and dichromatophism; tips of anal and dorsal fin pointed and with with short filamentous extensions in males, rounded in females; female dorsal fin 14-18 rays, male 17-18; female anal fin 17-20 rays, male 19-21; dark grey blotch in anterocentral portion of flank in females, flanks dark yellowish brown with minute golden to greenish golden spots concentrated on dorsolateral region in males (Costa, 2001).
Figure 3. Biotope E-BR 42-08 SW of Sitio do Mato; biotope of Cynolebias gibbus, view to the west, Estado do Bahia, NE Brazil.
Figure 2. Biotope E-BR 42-08 SW of Sitio do Mato; biotope of Cynolebias gibbus, view to the east, Estado do Bahia, NE Brazil.
Figure 4. Cynolebias gibbus, E-BR 42-08, female, anal fin
Figure 5. Cynolebias gibbus, E-BR 42-08, female, dorsal fin
Figure 6. Cynolebias gibbus, E-BR 42-08, female, head lateral close up
