COLUMBUS, Ohio -- Ohio State University aquaculturists have successfully bred and reared the first wild Amazonian catfish in North America, opening the doors for improved sustainability of a species fast becoming overexploited for food fish production.
Konrad Dabrowski, an aquaculturist with the School of Environment and Natural Resources, said that South American catfish of the Amazon region, mainly species Pseudoplatystoma faciatum, are popular with consumers throughout such countries as Argentina, Guyana, Brazil, Peru, Bolivia and Colombia because of excellent meat quality and minimal bones. However, overexploitation of wild fish for consumption is jeopardizing the viability of species.
"Fish caught in the wild along the Amazon, Parana or Orinoco rivers and tributaries have become very limited, so aquaculture of these species is of high priority," said Dabrowski, who holds a research appointment with the Ohio Agricultural Research and Development Center. "It is evident that studies promoting the artificial propagation of these fishes will improve the profitability of aquaculture operations for South American fish farmers and, consequently, economic conditions of rural communities that consume these species. In addition, readily available techniques of farming these fishes will reduce the pressure of catching fish from the wild."
The purpose of the Ohio State research was to complement South American studies in the areas of improving fish development, gaining a better understanding of reproductive physiology, and determining the nutritional requirements of larvae. The research project was a collaborative effort of Ohio State researchers with The Sao Paulo State University in Jaboticabal, Brazil, and The University of San Marcos in Lima, Peru.
"To the best of our knowledge, induced spawning of Pseudoplatystoma species has not been accomplished before in North America," said Dabrowski.
It took three years of research in reproductive development, hormone treatment to synchronize male and female sexual maturation, and the careful balance of water temperature and light requirements for an end result of the hatching of several thousand 3.5 millimeter hatchlings at Ohio State's tropical aquaculture laboratory on the Columbus campus last month.
"The hatchlings were out of their shells within 14 hours, one of the fastest rates of embryonic development in vertebrates," said Dabrowski. "This species is so voracious that if not given a sufficient diet, the fish will begin to cannibalize their own siblings within hours."
Pseudoplatystoma species, commonly known as tiger shovelnose catfish, are carnivorous bottom-feeders, growing over three feet long. Tiger shovelnose catfish have an elongated body and a long snout, with silver or brown bodies accented with black spots or stripes. The exotic species inhabit the South American waters of the Amazon, Corintijns, Essequibo, Orinoco and Parana basins, and are among 1,000 other catfish species that inhabit the Amazon region. Amazon catfish account for almost half of all the catfish species in the world.
The Ohio State research was funded by the U.S. Agency for International Development Aquaculture Collaborative Research Support Program and the Peruvian Science Foundation. Domestication of the species and developing selective breeding techniques are the goals of future research.