Acestrorhynchidae

The single genus Acestrorhynchus is currently represented by 15 species ranging from about 63 Acestrorhynchus minimus to 400 mm Acestrorhynchus falcirostris in standard length. Acestrorhynchid species are entirely confined to South America and the greatest species diversity occurs in the Amazon and Orinoco basins. Three species occur further south in the São Francisco, Paraná, Paraguay and La Plata drainages. They are found in a variety of habitats, but primarily live in lakes, lagoons, areas near shore, and the smallest species are especially found in small streams (igarapés) of the Amazon basin (personal observation and see also Britski et al., 1986). The peculiar dentition makes acestrorhynchid species very specialized predators among characiforms, most species feeding primarily on fishes. See Menezes, 1969a, Nico & Taphorn, 1985 and Amaral, 1990. After the major revision of Acestrorhynchus and the description of some new species (Menezes & Gery, 1983; Toledo-Piza & Menezes, 1996) not many new species are expected to be found. Acestrorhynchids are not commercially important as food fishes and two of the smallest species (A. nasutus and A. minimus) might be eventually found in aquarium shops. Acestrorhynchus abbreviatus 22.0 SL Acestrorhynchus altus 23.3 SL Acestrorhynchus apurensis 7.1 SL Acestrorhynchus britskii 16.5 SL Acestrorhynchus falcatus 27.2 SL Acestrorhynchus falcirostris 40.0 TL Acestrorhynchus grandoculis 10.8 SL Acestrorhynchus heterolepis 32.1 SL Acestrorhynchus isalineae 10.1 SL Acestrorhynchus lacustris 27.0 SL Acestrorhynchus maculipinna 7.9 SL Acestrorhynchus microlepis Pike characin 26.0 SL Acestrorhynchus minimus 6.3 SL Acestrorhynchus nasutus 6.9 SL Acestrorhynchus pantaneiro 24.0 SL