Lecithotrophic development of Hoplodoris nodulosa (Angas) (Opisthobranchia, Gastropoda)

Abstract

The intertidal nudibranch Hoplodoris nodulosa from New South Wales produces transparent egg ribbons which contain 400 to 700 ova. The zygotes range from 137 to 141 μm in diameter. Development up to hatching takes 16 days at 22–23°C. Embryos develop in a similar fashion to those of other nudibranchs with lecithotrophic development. Newly hatched veligers either begin metamorphosis immediately or go through a brief crawling-swimming stage for 24 hours before metamorphosis. They do not show any preference for a particular type of substratum on which to settle and metamorphose. The behaviour of the veligers indicates that this species mode of development is demersal rather than pelagic lecithotrophic.