Potential kleptoparasitism-scavenging interactions between crabs and shell-boring gastropods feeding on bivalve prey: a global survey

Abstract

Shell-boring gastropod molluscs and crabs are important predators of many bivalve molluscs, and impact bivalve populations and food webs. When gastropods and crabs target the same bivalve prey, complex interactions between them arise that mediate their impacts. Kleptoparasitism and scavenging (K-S) interactions result when one predator, usually the gastropod, loses or abandons its prey, which is then stolen or scavenged by the other. Such interactions have thus far only been reported among nine crab-gastropod species groups when they fed on shared bivalve prey, but potentially occur among many others. This study used the Global Biotic Interactions (GloBI) database to search for records of shell-boring gastropods and crabs preying on the same bivalve to identify tritrophic bivalve-crab-gastropod systems in which K-S interactions may occur. In total, 871 such systems were found, which included 58 bivalve species that were each eaten by 1-8 species of shell-boring gastropods and 1-19 species of crabs. In the vast majority of these systems (>99%), no previous report of K-S interactions has been published, although in 334 cases the gastropod and crab have been reported to undergo competitive or predator-prey interactions, which may indicate that K-S and other complex interactions occur among them. The tritrophic systems identified in the present survey should be investigated in future studies to determine whether the identified crab and gastropod taxa do in fact undergo K-S interactions. Doing so will enable the development of a theoretical framework for assessing the occurrence, evolution, utilization, and impacts of these interactions in natural systems.

Comparison of macro‐molluscan assemblages in a protected and a non‐protected tropical seagrass ecosystem

“…The feeding types referred to for the species in various publications and databases were used to assign the feeding guild and also to compile data on trophic groups (Allmon, 2011; Janssen et al, 2011; Nawrot et al, 2015; Palomares & Pauly, 2021; Poutiers, 1998; Sälgeback & Savazzi, 2006; Samsi et al, 2019; Solanki et al, 2017; Souji & Radhakrishnan, 2013; Tripathy et al, 2013; Wikipedia Contributors, 2021; WoRMS Editorial Board, 2021). The feeding guild (and thereby the trophic group) designation for the five species that were identified up to the genus level was based on their generic feeding behavior as determined in various studies (Eisapour et al, 2015; Nielsen, 1974; Quinn, 2020; Sarà et al, 2000; Williams et al, 2010; Yonge, 1949). The densities of species from the same trophic group were combined in each sub‐site and analyzed for trophic group diversity using the Shannon H ′ diversity index.…”