Pea crab-oyster interspecific interaction on tropical coast: Brachyuran pinnotherid Zaops ostreum (Say, 1817) living in the host bivalve ostreid Crassostrea brasiliana (Lamarck, 1819)

Abstract

In this study, we report the association between the pea crab Zaops ostreum (Say, 1817) living in the oyster Crassostrea brasiliana (Lamarck, 1819), collected in an estuarine region of Northeast Brazil. Oysters were collected along the mouth of the Santa Cruz Channel, Barra de Catuama (State of Pernambuco), between 2016 and 2017. A total of 224 oysters and 38 crabs were collected. Relative density of Z. ostreum was 16.96% (7.14% for males and 9.82% for females) in analyzed oysters. Prevalence during dry season ranged from 6.25% to 15.60%, whereas in rainy season ranged from 3.10% to 12.50%. Z. ostreum proportion of females to males was 1:0.73. Most occurrences were female-male couples (79.29%) with no isolated males or triple occupancy being observed. Female-male couples and ovigerous females were detected throughout most of the studied period, possibly indicating a distinct reproduction behaviour on tropical areas. This association expands knowledge on the aspects of social behaviour and host range of Z. ostreum, remarkably associated with bivalves of the Family Ostreidae.