Moridella brockii Bergh 1888, redescribed with notes on anatomy and early development

Abstract

The opisthobranchiate gastropod Moridella brockii Bergh 1888, has been described by its author based on a single specimen collected by Dr. J. Brock in 1884-85 from flie Sunda Sea. Ever since that time many later authors (Thiele, 1931 ; Macnae, 1954 ; Marcus, 1958 ; Risso-Dominguez, 1962 ; Edmunds, 1964 ; Risso-Dominguez, 1964) have referred to this species in their taxonomic work, but no material has actually been collected by any. During the course of an intensive collection for the littoral nudibranchs in the Gulf of Mannar and the Palk Bay near Mandapam, the author came across a large number of specimens of this species in a good size range from the Gulf of Mannar. Since this species has now been collected after seventysix years of its first description and also as it is little known to science, a detailed study of this monotypic genus was felt desirable. In the present communication besides a redescription of Sie species, some detailed observations made by the author on its anatomy, early development and ecology, which are the first of its kind are presented.