The life cycle of Eutima commensalis sp. nov. (Eutimidae,Hydromedusae)

Developmental stages of the medusa Eutima commensalis sp. nov. were obtained from plankton collections made at 2 fixed stations, one at Fareway Buoy and the other at Aroor in the Cochin backwater system. Six stages were arbitrarily assigned and described. The hydroid and the medusa of this form were found to occur in these waters throughout the year, except during the monsoon months from June to September. The hydroid is endocommensalic on wood-boring molluscs such as Nausitora hedleyi, Teredo furcifera and Martesia striata.