olbophorus daminificus is a commercially important trematode parasite within catfish aquaculture. Infection by this parasite can lead to reduced growth due to lack of feeding, as well as mortality. In severe cases, economic losses may also occur as a result of processing rejects due to a heavy parasite burden in surviving fish. The complex life cycle of the parasite consists of two intermediate hosts, snails and fish, and a single final host, piscivorous birds, making control and eradication difficult.
In catfish ponds, two snail species are known to serve as intermediate hosts of the trematode: the Marsh Ramshorn Planorbella trivolvis and the Ghost Ramshorn Biomphalaria havanensis. However, basic ecological information about these two snail species is still largely unknown, both in commercial aquaculture and in the wild. Information such as snail density, movement patterns, and seasonal behavior may all play important roles in the management of snail populations and their parasites. Thus, monitoring of snail populations in catfish ponds and development of a threshold density could help farmers make more informed management decisions throughout the production season.
This study evaluated the use of a small, cost-effective snail trap that could be easily implemented in catfish ponds and maintained by farm managers and employees. Traps were deployed in each of 8 commercial catfish ponds – 4 fingerling and 4 foodfish. Traps were checked every week from May to September to evaluate the numbers and species of snails present throughout the production season. Foodfish ponds produced significantly more snails than fingerling ponds throughout the season. Our data also show recovery of snail populations in less than one month following copper sulfate treatment. The results of this study show promise for the use of passive traps as tools for monitoring snail populations within catfish ponds. This study also suggests that fingerling and foodfish ponds likely differ in their ecology, and that copper sulfate treatments are a short-term solution that may require multiple applications and/or more targeted approaches.