The Anatomy and Life History of a Nudibranch Mollusc: Pellibranchus cinnabareus n.g. n.sp.

Abstract

Pellibranchus cinnabareus n.g. n.sp. is a small Nudibranch, which up to the present has only been found at Island Bay, Wellington, New Zealand. The limaciform adult, bright red in colour, lacks external gills or other appendages with the exception of a pair of relatively long erect tentacles on the head. The adults are found at all seasons on the lower surface of stones in tidal runnels along the shore. Packets of three to twentyfour eggs, the same colour as the adult, are found in the same position from September to May. Development is direct. The general form resembles the small lithophilus Elysiomorphs but the uniform bright red colour extending from the top over the sides and foot, the possession of a multi-seriate radula and hermaphrodite gland divided into male and female acini, enables the separation of this species from the other New Zealand Nudibranch members similar in size and habit. P. cinnabareus is placed in the Sub-order Dendronotacea Family Phylliroidae, following the classification of Odhner (1936). The family numbers seven species, and two genera-Cephalopyge, five species, and Phylliroe two species.