Larval development of the coronuloid barnacles Austrobalanus imperator (Darwin), Tetraclitella purpurascens (Wood) and Tesseropora rosea (Krauss) (Cirripedia,Tetraclitidae)

The presence of embryos in the mantle cavity of A. imperator, T. purpurascens and T. rosea was monitored over two years. Tesseropora rosea showed a clearly defined breeding season in summer and early autumn. Seasonal breeding in A. imperator and T. purpurascens was less well defined, a small number of gravid individuals being present during most of the year. Breeding increased during the late autumn and early winter in A. imperator and during winter, spring and early summer in T. purpurascens. The larval stages of A. imperator, T. purpurascens and T. rosea are described from larvae reared in the laboratory. Separation of the larval stages between these species depends on fine morphological detail. Distinctive larval features permit the separation of coronuloid larvae from those of the other balanomorph superfamilies, but coronuloid nauplii resemble balanoid nauplii more than chthamaloid nauplii.