Size-specific vulnerability of mollusks to juvenile black carp predation

• Published in: Biological invasions 2024-06, Vol.26 (6), p.1931-1940
• Main Authors: Runyon, Andrew D., Porreca, Anthony P., Yff, David J., Parkos, Joseph J.
• Format: Article
• Language: English
• Subjects: Biomedical and Life Sciences; Bladder; Carp; Developmental Biology; Ecology; Elimia livescens; Fingernail; Freshwater & Marine Ecology; Gastropoda; Life Sciences; Mollusca; Mollusks; Morphology; Mussels; Original Paper; Plant Sciences; Predation; Predators; Prey; River basins; Rivers; Shells; Snails; Survival; Survival analysis; Taxa
• ISSN: 1387-3547; 1573-1464
• DOI: 10.1007/s10530-024-03289-3

The black carp ( Mylopharyngodon piceus ) is a non-native molluscivore established in the Mississippi River Basin, USA. Given that it is not practical to directly measure predation risk for every mollusk species black carp may encounter in the Mississippi River Basin, investigating morphological traits that influence vulnerability can provide a basis for making predictions of predator–prey outcomes for a variety of prey types. We conducted laboratory experiments to quantify size-specific vulnerability of native and nonnative mollusk taxa to consumption by juvenile black carp. Mollusks tested represented a range of shell morphologies and included bladder snails ( Physella sp.), liver elimia ( Elimia livescens ), Chinese mystery snails ( Cipangopaludina chinensis ), Asian clams ( Corbicula fluminea ), fingernail clams ( Sphaerium sp.), and attached and unattached zebra mussels ( Dreissena polymorpha ). Thick-shelled Asian clams were vulnerable over a narrower size range compared to the similarly shaped, but thin-shelled fingernail clams, which were vulnerable at shell widths up to 80% of predator mouth gape. Unattached zebra mussels were highly vulnerable across a wide range of shell sizes, with 95% of unattached individuals crushed or consumed, while attached zebra mussels were vulnerable over a narrower range of sizes and had a 46% higher survival rate. All three snail taxa were vulnerable at sizes exceeding black carp mouth gape, with bladder snails especially vulnerable (100% of individuals consumed). Interspecific differences among mollusks tested suggest juvenile black carp are limited by crushing ability and the relative shell size of their prey. For gastropods, elongate, tightly coiled shells were less vulnerable than wider, loosely coiled shells. For bivalves, round shell shapes were less vulnerable than elongate forms, and firm attachment reduced vulnerability. Our study suggests that juvenile black carp are capable of consuming a wide variety of shelled prey and their functional limitations as predators may be predicted based on the features of mollusk shells.