Two galatheid associates of crinoids from the Ryukyu Islands (Decapoda: Anomura: Galatheidae), with their ecological notes

Abstract

Galathea amboinensis De Man, 1888 and G. inflata Potts, 1915, both known as associates of shallow water comatulid crinoids, are reported for the first time from Japan. In the Ryukyu Islands, Galathea inflata was found on 13 species of crinoids but most commonly on Comanthus parvicirrus (Miiller) and Comaster schlegelii (Carpenter). Galathea amboinensis 'was recorded from 10 crinoid species but more often on Capillaster multiradiatus (Linnaeus) than on other crinoids. Heterosexual pairs of G. inflata were found on 26.3 % of host crinoids (n=57), and all females were ovigerous. Megalopae of both galatheids were found on hosts, indicating that the larvae settled on crinoids at the megalopa stage.