First reports of protists in land crabs of the family Gecarcinidae (Crustacea: Decapoda: Brachyura) suggest a relatively widespread phenomenon

Abstract

ABSTRACT Eccrinales are protists of the class Mesomycetozoea exclusively found in the digestive tract of marine, freshwater and terrestrial arthropods. Isopods are the only terrestrial crustaceans from which eccrinids have been reported. Among brachyuran crabs, eccrinids were exclusively reported in grapsid and ocypodid crabs, with a percentage of occurrence ranging from 5% to 100% in the respective species. The eccrinid Enteromyces callianassae Lichtwardt, 1961 has been found in the guts of various decapod crustacean species in marine habitats and intertidal mud or sand flats in Chile, France, Japan and the USA. Semi-terrestrial species of Leptuca and Minuca were the most terrestrial crabs in which E. callianassae has been observed. Here we report the presence of E. callianassae in stomachs of the land crab Gecarcinus lateralis. These are the first observations of protists in gecarcinid crabs, which are regarded as the most terrestrial brachyuran crabs. The presence of E. callianassae in 11% of 74 examined stomachs from males and females of G. lateralis from three locations in Costa Rica suggests that the occurence of E. callianassae in these crabs is a relatively widespread phenomenon. Considering that these highly terrestrial crabs are important herbivores on island and continental landscapes, the presence of eccrinids in the stomachs of these crabs may have important implications for the carbon cycling in coastal ecosystems.