Artificial propagation of Amazonian catfish in captivity

School of Environment and Natural Resources Ohio State University Extension Columbus, Ohio, USA Leonardo et al. (2004) obtained 100% ovulation in females of P. fasciatum maintained in ponds in Sao Paulo State, Brazil, following hormonal injections of carp pituitary extract (CPE) or human chorionic gonadotropin (hCG). In that study, the most detailed thus far, females released between 17 and 20% of hydrated oocytes (expressed per wet body weight) and fertilization was not different between 3and 4-year-old fish, with levels of 54 and 56%, respectively. Most recently Nunez et al. (2008) induced spawning in catfish P. fasciatum caught in the wild and then maintained in ponds for the following year. Fish were injected intraperitoneally with two doses of Ovaprim (Syndel, Qualicum Beach, Canada) and 74% of ovulation responses were observed in the course of the spawning season. Some of the fish responded 2–4 times in the course of 5 months under pond conditions, at sites located in the Bolivian Amazon. Furthermore, eggs were collected 8.5 h after resolving injection (90% of the dose) at 27.6°C. They reported an excellent hatching rate of 23 ovulation responses of 73.7%. Based on these multiple spawnings, Nunez et al. (2008) provided the mean fecundity for surubim of 147,000 eggs per kg. Introduction South American catfishes (e.g., Pseudoplatystoma corruscans, P. fasciatum, and P. tigrinum) have the potential to be important species for commercial production in South America (Kossowski, 1996). Spawning of Pseudoplatystoma sp. occurs in South America between October and February and this also includes fish maintained in ponds. For instance, Carolsfeld et al. (2003) observed that carp pituitary injections resulted in ovulation and spermiation in P. coruscans maintained in ponds in Minas Gerais State, Brazil, between December and January. Godinho et al. (2007) concluded that “sprint migrations” at 31 km per day are an intimate part of spawning behavior of P. corruscans in Sao Francisco River, Brazil. It is well documented that exercise is an important component of maturation process and perhaps a physiological stimulus for the onset of gametogenesis and determinant of the gamete quality in fish (van Ginneken et al. 2007). Godinho et al. (2007) also suggested, based on tagging spawning fish between November and March, that P. corruscans is a multiple spawner.