New Chapter Godinho, H. P. and A. T. M. Viveiros. 2011. Current Status of Sperm Cryopreservation of Brazilian Characiform Fishes. In: Cryopreservation in Aquatic Species, 2 nd Edition. T. R. Tiersch and C. C. Green, editors. World Aquaculture Society, Baton Rouge, Louisiana. Pp. 875-884. Current Status of Sperm Cryopreservation of Brazilian Characiform Fishes H. P. Godinho and Ana T. M. Viveiros Introduction The order Characiformes includes a large variety of exclusively freshwater fish families and species in Africa and the New World. In the Americas, characiforms are found from Texas in North America throughout Central and South America, encompassing ~1000 species (Buckup et al. 2007) which correspond to about 38% of all known neotropical species. These fishes range in length from a few cm (e.g., glandulocaudines, genus Mimagoniates) to over 90 cm (e.g., ‘dourados’, genus Salminus). Characiforms have commercial importance as ornamental species (e.g., small cardinal-tetras, genus Paracheirodon), fisheries food resources (e.g., mud-eating prochilodontids, genus Prochilodus), aquaculture (e.g., ‘pacus’, genus Piaractus), or sport fishing (e.g., dourados). Today, fingerlings of several characiforms are hatchery produced for aquaculture and stock enhancement (Godinho 2007). All characiforms that have had sperm cryopreserved to this date (Table 1) are highly fecund, external fertilizers, and migratory, except Brycon nattereri for which no information on migratory condition is available. Besides their ecological and practical importance, cryopreservation in characiforms sperm is valuable as it can be used to improve genetic quality of fingerlings produced in Brazilian hatcheries. In addition, some characiforms discussed in this chapter are of special concern because they are under threat of extinction (e.g., ‘matrinchãs’, Table 1. Brazilian characiforms studied for sperm cryopreservation during the past decade. Family* Species Common names Prochilodontidae Prochilodus lineatus Streaked prochilod, curimba Anostomidae Leporinus elongatus Piapara Leporinus macrocephalus Piaussu, piau-açu Leporinus obtusidens Piapara Characidae Brycon amazonicus (=B. siebenthalae) Yamú, jatuarana, matrinchã Brycon cephalus (possibly B. amazonicus) Matrinxã Brycon insignis** Tiete tetra, piabanha Brycon nattereri** Pirapitinga Brycon opalinus** Pirapitinga-do-sul Brycon orbignyanus** Piracanjuba, piracanjuva Brycon orthotaenia (=B. lundii) Matrinchã Colossoma macropomum Cachama, tambaqui Piaractus brachypomus Pirapitinga, cachama blanca Piaractus mesopotamicus Pacu, pacu-caranha Salminus brasiliensis Dorado *Following Reis et al. (2003). **Registered in the national list of endangered species (Brasil 2004).