Captive propagation has become an important tool in the conservation of imperiled freshwater mussels. Previous studies provide conflicting results about the effects of food abundance on survival and growth of juvenile mussels in aquaculture, and the extent to which growth in the hatchery reflects growth in the wild is unknown. We evaluated the effects of abundance of an algal-based diet on survival and growth of juvenile Cumberland Bean (Venustaconcha troostensis) in a recirculating aquaculture system. We compared food abundance (as fine particulate organic matter, FPOM) in our experimental food rations with FPOM in 14 streams to assess the similarity of hatchery and natural food sources. We compared growth in our experiments with previously published growth estimates of Cumberland Bean at 17 stream sites. Growth in the hatchery increased linearly with increasing food abundance from 3.5 to 27.6 mg/L algal dry mass (about 111,000–1,147,225 cells/mL), and mussel size after two weeks increased 2.9% for every doubling of algal dry mass within the range of our experimental rations. We observed no negative effects of increasing food abundance on survival, and ammonia concentrations remained below chronic effect concentrations in all treatments, even in food rations much higher than recommended by previous studies. FPOM in our experiments spanned a similar range of values as FPOM in streams. Growth in our experiments was similar to growth in streams, but our experimental temperatures were higher than in streams. When the probable effect of temperature was accounted for, growth in most experimental food rations was substantially lower than expected in streams despite similar FPOM. This suggests that food quality or other conditions are more favorable for mussel growth in the wild.
Bibliographical noteFunding Information:
We thank Andy McDonald, Adam Shephard, Meghan Owings, Travis Bailey, Travis Williams, and Julianne Jacobs for assistance in the hatchery and laboratory. Ning Wang provided information and discussion about ammonia chronic criteria. This study was supported by the U.S. Fish and Wildlife Service Ohio River Basin Fish Habitat Partnership, Kentucky Waterways Alliance , U.S. Forest Service Southern Research Station , University of Kentucky Department of Forestry and Natural Resources, and the McIntire-Stennis Cooperative Forestry Research Program .
- Captive propagation
ASJC Scopus subject areas
- Aquatic Science