The taxonomy and biology of further aeolidacean and arminacean nudibranch molluscs with symbiotic zooxanthellae

The occurrence of symbiotic zooxanthellae in further aeolid and arminacean nudibranch molluscs is described for the first time. The aeolid Aeolidiopsis ransoni Pruvot-Fol is redescribed, and a new species of Aeolidiopsis , also feeding on the colonial zoantharian Palythoa , is described. Both have symbiotic zooxanthellae. The taxonomy of the family Aeolidiidae is discussed and the genus Berghia Trinchese, 1877 is considered a synonym of Spurilla Bergh, 1864. Spurilla major (Eliot, 1903) and a new species of Spurilla are reported to have zooxanthellae while another new species of Spurilla is without zooxanthellae. The glaucid aeolid Pteraeolidia ianthina (Angas) is shown to have symbiotic zooxanthellae, as is the arminacean Doridomorpha gardineri Eliot, which is reported to feed on the alcyonarian blue coral, Heliopora. In all cases, the morphological adaptations developed for this symbiosis are described. Further notes on the Porites-fetding arminacean Pinufius rebus Marcus & Marcus and the aeolid Phestilla lugubris (Bergh) are included and a facultative symbiosis with zooxanthellae is suggested for the latter. The tion of symbiosis with zooxanthellae within nudibranchs is discussed and it is suggested that the relationship has evolved independently on several occasions.     

Further studies on the anatomy and ecology of opisthobranch molluscs feeding on the scleractinian coral Pontes

Three further species of opisthobranch molluscs are reported to feed on the scleractinian coral Pontes in Tanzania. Further information on Cuthona poritophages Rudman, 1979, is also included. The anatomy of the aeolid Phestilla lugubris {Bergh, 1870, = P. sibogae Bergh, 1905) and a new species of Phestilla is described, as is the anatomy of the arminacean Pinufius rebus. The new species of Phestilla , and Pinufius , are, for the first time, reported to feed on Porites. Notes on the anatomy of the type-species of Phestilla, P. melanobrachia Bergh, 1874, are included to make possible a definition of the genus Phestilla.
Aspects of the feeding biology, life history, defence mechanisms and habitat specificity of the four Porites-feeding opisthobranchs are described and discussed. The four species are shown to have evolved radular teeth of remarkably similar shape. Each species utilizes a different part of the coral tissue as food. The three aeolids have replaced functional cnidosacs at the tip of their cerata with batteries of large secretory cells.
Phestilla lugubris and Pinufius rebus are also reported for the first time from the Great Barrier Reef, Queensland and the new species of Phestilla is reported from Queensland and Hawaii.