Previous knowledge on Haplosyllis species from the northernmost regions of the Indian Ocean (including the Red Sea) is confusing, with H. djiboutiensis as the only species originally described in the area. This species was later synonymised with H. spongicola, which in turn was widely reported all along the region. Among these reports, two referred to populations associated to the sponges Theonella swinhoei Gray, 1868 and Liosina paradoxa Thielle, 1899, from the Red Sea and the Indian Ocean, which proved to have enough marked morphological differences not only to be distinguished from each other, but also from H. spongicola and H. djiboutiensis. Accordingly, these specimens are herein illustrated, compared and described as new species. Haplosyllis eldagainoae sp. nov. is distinguished by a broad aciculae, short and curved chaetal mid-joining point and last article of dorsal cirri very long. Haplosyllis giuseppemagninoi sp. nov. resembles H. djiboutiensis in chaetal shape and body size (small), but may be differentiated by its broad aciculae and the presence of single chaetae on mid-body parapodia. Finally, the description of H. djiboutiensis is complemented with new data on its intra-specific chaetal variability, reproduction and ecology, and the Persian Gulf specimens are compared with those from nearby areas.

Peer reviewed