The Mussel–Fish Relationship: A Potential New Twist in North America?

Abstract

North American freshwater mussels are critically imperiled organisms that generally require fish hosts in order to complete their life cycle. Although numerous studies have focused on the parasitic relationship between mussels and fishes, few have examined the benefits that mussels provide to other organisms. During sampling of Altamaha River, Georgia, we observed foreign eggs occurring within body cavities of native mussels across a 253‐km reach of the river basin. Eggs were recovered from 6% of the 757 mussels examined among seven sites. Foreign eggs were present in 17% and 18% of examined mussels at two sites. Using molecular techniques, eggs were identified as American Shad Alosa sapidissima. This discovery appears to be the first documented occurrence of native fish eggs in live North American mussels. Further research into the nature and mechanism of this symbiosis is warranted to assess whether this relationship is amensalistic, mutualistic, or commensalistic as American Shad and many freshwater mussels are species of conservation concern. A commensalistic or mutualistic relationship between these taxa may result in restoration activities affecting one species facilitating restoration of others.

An exploration of the hidden endosymbionts of Corbicula in the native range

“…A classic example of spawning relationships between fish and freshwater mussels is bitterling: unionid mussel associations (Reichard et al, 2007). Additionally, several cyprinid fishes in the genus Barbus and the clupeid species Alosa sapidissima place eggs into the gills of freshwater mussels (Wisniewski et al, 2013). Our study has added one more fish species to the list describing the complex relationship between fish and freshwater bivalves.…”

What are Freshwater Mussels Worth?

“…The physical structures that mussels produce may have other value as well. In addition to sheltering invertebrates, mussels and their shells provide spawning sites and shelter for some fishes (Chatelain and Chabot 1983;Etnier and Starnes 1993;Aldridge 1999;Wisniewski et al 2013). They presumably could alter near-bed and interstitial water flows as well, which could affect local habitat structure and Figure 3.…”