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Presented at the NABS Annual meeting, Pittsburgh, Pennsylvania, 2002
in Unionid Ecology
PATTERNS OF REPRODUCTION AND PARASITISM IN FRESHWATER MUSSELS.
G.T. Watters. Department of Evolution, Ecology, and Organismal Biology, Ohio State University, Columbus, Ohio, USA 43212
Freshwater mussels have evolved methods of increasing the odds of parasitizing their hosts beyond simply releasing their larvae at random. Two methods are evident: generalists and specialists. Generalists may parasitize more types of hosts than specialists but require more glochidia because they cannot create host-specific lures. Specialists require fewer glochidia but can only attract a small subset of available hosts. Thus there is a trade-off between the energy needed to make lures versus the degree of specialization. Mussels also have different patterns of timing for glochidial release. Overwintering glochidia on hosts may result in increased growth during the first year but is more risky than overwintering glochidia in the marsupium. Again, there are tradeoffs between possible strategies. Host overwintering may result in increased juvenile fitness but is more risky. Overall, freshwater mussel patterns of reproduction and parasitism involve well-defined, but often contrary, strategies.
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