Astyanax burgerai

description

Description. Morphometric data of holotype and paratypes presented in Table 2. Body somewhat compressed and elongate. Greatest body depth along vertical slightly behind midlength of pectoral fin. Dorsal profile of head convex from upper lip to vertical through anterior nostrils; straight to slightly convex from latter point to tip of supraoccipital spine and moderately convex from this point to dorsal-fin origin. Body profile straight and posteroventrally slanted along dorsal-fin base; straight from dorsal-fin base terminus to adipose fin, and slightly concave along caudal peduncle. Ventral profile of head and body convex on its anteriormost portion and moderately convex from region below eye to anal-fin origin. Body profile along anal-fin base straight and posterodorsally slanted. Ventral profile of caudal peduncle nearly straight to slightly concave. Head somewhat pointed anteriorly in lateral profile; mouth terminal. Posterior terminus of maxilla trespassing vertical through anterior margin of orbit. Premaxillary teeth in two rows. Outer row with 2 * (6) or 3 (8) teeth bearing 3 cusps. Inner row with 4 (1), 5 * (13), teeth bearing 5 to 7 cusps. Symphyseal tooth of inner series r

Astyanax vermilion and Astyanax burgerai: new characid fishes (Ostariophysi: Characiformes) from Northeastern Bahia, Brazil

diagnosis

Diagnosis. Astyanax burgerai can be distinguished from all other Astyanax species known from northeastern Brazilian drainages (A. brevirhinus, A. epiagos, A. fasciatus, A. intermedius, A. jacobinae, A. lacustris, A. pelecus, A. rivularis, A. taeniatus, and A. turmalinensis) by the presence of two vertically elongated humeral blotches (vs. only one humeral blotch, rounded or distinctly horizontally elongated in A. brevirhinus, A. lacustris and A. pelecus, and vertically elongated in A. epiagos, A. fasciatus, A. intermedius, A. jacobinae, A. rivularis, and A. taeniatus), absence of a conspicuous and broad dark midlateral stripe, at least on anterior half of body (vs. presence in A. brevirhinus, A. fasciatus, A. intermedius, A. jacobinae, A. rivularis, A. taeniatus, and A. turmalinensis), body highest along vertical slightly behind midlength of pectoral fin (vs. highest body depth just anterior to dorsal-fin origin in A. brevirhinus, A. fasciatus, A. lacustris, A. pelecus, A. taeniatus, and A. turmalinensis), 31 - 34 lateralline perforated scales (vs. 35 or more in A. brevirhinus, A. intermedius, A. jacobinae, A. pelecus, and A. rivularis), and two or three teeth on premaxillary outer

Astyanax vermilion and Astyanax burgerai: new characid fishes (Ostariophysi: Characiformes) from Northeastern Bahia, Brazil

distribution

Geographic distribution and ecological notes. Astyanax burgerai is known only from córrego Água Boa, a streamlet on the road between Floresta Azul and Almadina, tributary of riacho Pancadinha, itself a tributary of rio Almada, a coastal drainage on southern Bahia, Brazil (Fig. 4). The species was collected at 212 meters of altitude, in clear water stream, running over rocky and sandy bottom, in habitat characterized by very small pools, 20 - 70 cm deep (Fig. 8). The surrounding vegetation is composed by remains of the Atlantic Forest, with trees and shrubs. The only other syntopic species is Trichomycterus cf. bahianus. The analysis of the stomach contents of two specimens revealed the presence of filamentous algae, fragments of arthropods, fragments of vascular plants and organic debris.

Astyanax vermilion and Astyanax burgerai: new characid fishes (Ostariophysi: Characiformes) from Northeastern Bahia, Brazil

etymology

Etymology. Thename burgerai isgiveninhonorofRafaelBurger, a student who enthusiastically collected the new species.

Astyanax vermilion and Astyanax burgerai: new characid fishes (Ostariophysi: Characiformes) from Northeastern Bahia, Brazil