Selective Feeding of Freshwater mussels: Implications for Resource Partitioning

Date

2017-10-03

Authors

Tran, Katherine

Journal Title

Journal ISSN

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Publisher

University of Guelph

Abstract

This study examined the feeding of three co-occurring freshwater mussel species in the Sydenham River at Florence, ON (a turbid river with over 25 unionid species), under static and ecologically relevant flow conditions. Experiments were designed to examine the change in algal composition (clearance rate and feeding electivity) following a feeding experiment in a recirculating flow chamber and an aerated tank to determine whether co-existing mussels feed selectively and/or partition algal resources. I hypothesized that mussel species found within the same reach of a river would feed differently and/or selectively on different algal taxa at different flow to limit competition for resources and therefore coexist. I found that the clearance rate was higher under flowing conditions across all the mussel species on natural seston from a turbid river. This was also found for specific algal taxa, which were identified using a flow cytometer, where higher feeding was observed on four of the nine algal taxa under flowing conditions. All three mussel species selected for larger particles within a 28-35 m size fraction, while rejecting smaller particles (12-19 m). Jacob’s Modified Electivity index was calculated for each specific algal taxon, while mussels did not appear to partition resources by size, there was evidence that different mussel species are capable of selectively feeding on different algal species. This study suggests that the maintenance of mussel diversity within the same river may be facilitated by resource partitioning.

Description

Keywords

Selective feeding, Resource partitioning, Freshwater Mussels

Citation