The specimens of Paralepas maculata on a sea urchin, Prionocidaris sp. were collected in Okinawa, southern Japan. This species has not been reported since its original description. This represents the first observation of this species from Okinawa and the first instance found on this sea urchin species. In this paper, the morphology of the new P. maculata specimens is reported, and compared with the type series of this species. Small individuals were found on the holotype. The probable androdioecious sexual system of the species, which includes dwarf-male like individuals and hermaphrodites, is discussed. This study was facilitated by the collaboration of scientists and aquarium staff, suggesting the potential of such collaborations in biodiversity studies.

The sexuality of large (non-dwarf) individuals and the characteristics of eggs, larvae and dwarf males were investigated in the pedunculate barnacle Scalpellum stearnsii. All 103 large individuals collected in this study were not hermaphrodites but females. The major length axis of the egg was on average 0.50 mm, which was larger than that in most thoracican barnacles with planktotrophic larvae. The larvae hatched as nauplii and metamorphosed into cyprids without feeding (i.e. lecithotrophic development). There was a positive relationship between body weight and egg mass weight in ovigerous females. The number of males attached per female ranged from 0 to 35 (average: 5.9) and there was a positive relationship between the number of males and female body weight. The distribution of dwarf males was skewed significantly towards the lower part of the occludent margin, which is near the fertilization site.