Two new species of tetra from the Astyanax genus have been discovered in Brazil.
The new characins, which are members of the family Characidae, have been named Astyanax microschemos and Astyanax pelecus by Vinicius Bertaco and Carlos de Lucena in a paper in the journal Neotropical Ichthyology.
A. microschemos was found in the Corrego Palmital area of the Rio Itapemirim drainage, while A. pelecus was found in the Rio Pardo drainage in Bahia, Brazil.
Astyanax microschemos has a massive head, shallow body, short snout and a vertically-elongated black humeral spot, which is a characteristic of the members of the Astyanax scabripinnis group.
Astyanax pelecus has a humeral spot above the lateral line, as well as a dark stripe running along the middle of its flanks from the edge of the gill cover to the base of the tail.
Both species also have some morphomeristic features that set them apart from other Astyanax species.
A. microschemos has a shallower body depth than others, at around 26.9-29.7% of its body length, it also has 14-18 branched anal rays and a smaller interorbital width.
Astyanax pelecus differs from other Astyanax species by a body depth of 26.7-34.8% of standard length, 16-18 branched anal rays and 38-39 scales in the lateral line series.
For more information on the new tropical fish species see the paper: Bertaco VA and CAS de Lucena (2006) - Two new species of Astyanax (Ostariophysi: Characiformes: Characidae) from eastern Brazil, with a synopsis of the Astyanax scabripinnis species complex. Neotropical Ichthyology, 4(1):53-60, 2006.
Astyanax species distributionsThe members of the Astyanax genus are quite widespread through South and Central America and the genus currently contains around 90 valid species. You can view the distributions of some of these fishes on Practical Fishkeeping's Fish Mapper application.
Astyanax abramis
Astyanax alburnus
Astyanax altiparanae
Astyanax angustifrons
Astyanax anterior
Astyanax argyrimarginatus
Astyanax armandoi
Astyanax asuncionensis
Astyanax atratoensis
Astyanax bimaculatus
Astyanax bourgeti
Astyanax brachypterygium
Astyanax brevirhinus
Astyanax caucanus
Astyanax chaparae
Astyanax cordovae
Astyanax correntinus
Astyanax cremnobates
Astyanax daguae
Astyanax depressirostris
Astyanax eigenmanniorum
Astyanax erythropterus
Astyanax fasciatus
Astyanax fasslii
Astyanax festae
Astyanax filiferus
Astyanax gisleni
Astyanax giton
Astyanax goyacensis
Astyanax gracilior
Astyanax guaporensis
Astyanax guianensis
Astyanax gymnogenys
Astyanax hastatus
Astyanax integer
Astyanax intermedius
Astyanax ita
Astyanax jacuhiensis
Astyanax janeiroensis
Astyanax jenynsii
Astyanax jordani
Astyanax kennedyi
Astyanax kompi
Astyanax kullanderi
Astyanax latens
Astyanax laticeps
Astyanax leonidas
Astyanax leopoldi
Astyanax lineatus
Astyanax longior
Astyanax maculisquamis
Astyanax magdalenae
Astyanax marionae
Astyanax maximus
Astyanax megaspilura
Astyanax mexicanus
Astyanax microlepis
Astyanax multidens
Astyanax mutator
Astyanax myersi
Astyanax nasutus
Astyanax nicaraguensis
Astyanax obscurus
Astyanax ojiara
Astyanax orbignyanus
Astyanax orthodus
Astyanax paraguayensis
Astyanax parahybae
Astyanax paranahybae
Astyanax paris
Astyanax pelegrini
Astyanax poetzschkei
Astyanax pynandi
Astyanax ribeirae
Astyanax robustus
Astyanax ruberrimus
Astyanax saguazu
Astyanax saltor
Astyanax scabripinnis
Astyanax schubarti
Astyanax scintillans
Astyanax stenohalinus
Astyanax stilbe
Astyanax superbus
Astyanax symmetricus
Astyanax taeniatus
Astyanax trierythropterus
Astyanax troya
Astyanax turmalinensis
Astyanax unitaeniatus
Astyanax validus
Astyanax venezuelae
Astyanax villwocki