Brazilian ichthyologists Angela Zanata and Priscila Camelier have described two new species of Astyanax tetras from eastern Brazil.
Brazilian ichthyologists Angela Zanata and Priscila Camelier have described two new species of Astyanax tetras from eastern Brazil.
Naming the two species Astyanax vermilion and Astyanax burgerai, the authors published the descriptions in a recent issue of the journal Neotropical Ichthyology.
Astyanax vermilion is distinguished from geographically proximate congeners in having a dark end portion of the pelvic fin, the lower part of the caudal peduncle and all fins (except the pectorals) reddish in life, inconspicuous humeral and caudal spots, the highest body depth just in front of the dorsal-fin origin, 32"34 lateral-line scales, five scale rows between the dorsal fin origin and the lateral line, three scale rows between the lateral line and the pelvic-fin origin, 8"12 scales on the base of the anterior anal-fin rays, one or two maxillary teeth, teeth with no more than five cusps and abruptly becoming smaller posteriorly, 20"23 branched anal-fin rays, and dorsal fin usually with eight branched and one unbranched rays.
This species is known from the Cachoeira and Almada river drainages in eastern Brazil, where it was collected in clear water streams, running over rocky, pebbles and sand bottom, in habitats characterized by slow to moderate water current and less than one metre deep.
Astyanax burgerai can be distinguished from geographically proximate congeners in having two vertically elongated humeral blotches, absence of a conspicuous and broad dark midlateral stripe, dark fins, body highest along a vertical slightly behind the middle of the pectoral fin, 31"34 lateral-line scales, 3"6 scales on the base of the anterior anal-fin rays two or three teeth on the premaxillary outer series, one or two maxillary teeth, 21"22 anal-fin rays (18"19 branched), and nine branched dorsal-fin rays.
This species is known from the Almada River drainage, where it was collected in a clear water stream running over rocky and sandy bottom, in habitat characterized by very small pools and 20"70 cm deep.
For more information, see the paper: Zanata, AM and P Camelier (2009) Astyanax vermilion and Astyanax burgerai: new characid fishes (Ostariophysi: Characiformes) from Northeastern Bahia, Brazil. Neotropical Ichthyology 7, pp. 175"184.