ニュージーランド, KaikouraのEuryolambrus australisの食性と保護色

Abstract

Foregut contents of Eurynolambrus australis from the intertidal zone at Kaikoura, New Zealand, showed that a coralline alga (Corallina officinalis) was the most important dietary component, occurring in 94.6% of the crabs examined (constituting 55.0% of diet). Isopods, amphipods, decapods, as well as red, green and brown algae were also common components of the diet. There were no differences in diet between male and female crabs, or crabs collected from different sites. Ontogenetic differences in diet were observed, with larger crabs consuming more decapods, gastropods, coralline and brown algae, while small and medium-sized crabs consumed more amphipods. Much of the animal component of the diet can be attributed to specialist grazing on a coralline alga which may also be a source of pigments helping to camouflage the crab.