A link between predator density and arm loss in the starfish Marthasterias glacialis and Asterias rubens

Abstract

Arm loss in two species of starfish Marthasterias glacialis and Asterias rubens (Echinodermata: Asteroidea) was recorded at eight sites in Lough Hyne, south-west Ireland. There was a significant positive correlation between the density of predators (Luidia ciliaris (Echinodermata: Asteroidea) and Cancer pagurus (Crustacea: Brachyura)) and arm loss in both species of starfish. The results suggest that predators may be responsible for a significant proportion of observed arm loss in these two species of starfish in Lough Hyne.