New distribution and host record for the starfish parasite Dendrogaster (Crustacea: Ascothoracida)

Abstract

This work presents the description of an intracoelomic parasite of the genus Dendrogaster (Crustacea: Ascothoracida), the largest ever reported, collected for the first time from the starfish Hippasteria phrygiana in the deep waters of the St Lawrence Estuary (eastern Canada). The parasite bears a close resemblance to only one previously described species, D. arbusculus from the west American coast, suggesting a bicoastal and possibly circumpolar distribution. Female growth is concurrent with embryo development and the parasite may have a negative impact on host starfish densities through gonad atrophy. This research also demystifies the old and persistent description of a supposed parasite in H. phrygiana 70 years ago, Laocoön paradoxus, and finally concludes that this parasite never existed and in fact represents the water vascular system found in all starfish.