Laboratory Culture of Zebra ( Dreissena polymorpha) and Quagga ( D. bugensis) Mussel Larvae Using Estuarine Algae

Abstract

Zebra ( Dreissena polymorpha) and quagga mussel (D. bugensis) larvae were reared through and beyond metamorphosis in the laboratory on diets of the estuarine algae, Isochrysis galbana T-Iso and Pavlova ( = Monochrysis) lutheri. Larvae were successfully spawned and raised in the laboratory for over 1 year with routine survival to settlement. Some adult males reared from an August 1994 spawn reached sexual maturity with active sperm by April 1995. Diets of dried Chlorella sp. and Synecococchus sp. were unable to support larvae. Settlement of pediveligers at 22°C occurred at ≈ 21 days for zebra mussel and 32 days for quagga mussels. Saturated fatty acids predominated in I. galbana and P. lutheri, whereas polyunsaturated fatty acids (PUFAs) predominated in Chlorella sp. The process to culture dreissenid larvae in the laboratory is very labor-intensive and requires continuous culture of live algae maintained in log growth phase. Larvae are fed every other day at a density of 2 × 10 5 cells mL −1 for the first week, and then daily densities of 3–5 × 10 5 cells mL −1 thereafter. Water quality is critical. Larvae and juveniles should be stocked at densities of ≈ l mL −1 and the water must be changed at least 3× wk −1 in static cultures. Water must be changed at least weekly in tanks holding adult brood stock. Methods of controlling protozoan and rotifer infestation of cultures are also important for successful culture.