Along the w d y beach of Parto-Nwo Omphis etwmita occur commonly. Trochophore larvae of 0. eremita were collected from the surfaa plankton of Vellar estuary and nearahore waters of Porto-Novo. They were mred in the laboratory and different stages of development upto settlement wek studied and the trochophore and nedochaete larvae with three to seven getigcrous segments were described. At seventh sctiger stage, the larva developed almost all characters and metamorphosed into adult.

0. eremita larvae occumd throughout the yur in Porto Nwo watas and their distribution was from nearahon witas to the tide1 zone of the Vellar estuary indicating high salinity tolerana. The highest records of this larvae were 500 no./m3 in day collections and 740 no./m3 in night collections. The highest
iarval density was found at the mouth of the estuary.

Keywords