Entanglement and ingestion of microfibers by the oyster pea crab Zaops ostreum, an endosymbiont of the eastern oyster Crassostrea virginica

Abstract

The kleptoparasitic pea crab Zaops ostreum lives within the gills of bivalves, including the economically important eastern oyster Crassostrea virginica. Previous research along the east coast of central Florida has found an average of 2.3 pieces of plastic per oyster. The goals of our research were to determine if filter-feeding oysters transfer microfibers to Z. ostreum via the crab: 1) actively consuming plastic particles, or 2) passively becoming entangled in microfibers. Our results show that both occur. While only 11.6 % of Z. ostreum (total n = 122) consumed microfibers, those that did had up to 14 pieces in their soft tissues. Similarly, only 7.4 % of Z. ostreum had microfibers entangled around their appendages. Mean lengths of consumed and entangled fibers were similar, 1.9 and 2.7 mm, respectively. Additional research is needed to understand the positive and negative impacts of microfibers associated with pea crabs on both species.

Keywords: Bivalve; Estuary; Florida; Indian River Lagoon; Microplastics.