Taxonomy, reproduction and ecology of new and known Red Sea sponges

Ten of the most abundant sponge species from the northern Red Sea were studied. Six of them are new species that are described here: Callyspongia paralia, Hemimycale arabica, Rhabderemia batatas, Niphates rowi, Petrosia elephantotus, and Topsentia aqabaensis. An additional species has been reassigned and renamed: Dactylochalina viridis Keller, 1889 was assigned to Amphimedon and renamed A. chloros to avoid homonymy with A. viridis Duch. & Mich. Callyspongia paralia and N. rowi were found restricted to shallow water (<4 m), whereas the other species were also detected in deeper water. The reproduction of most of these new species as well as of Theonella swinhoei Gray, 1868, and Theonella conica (Kieschnick, 1896) was determined based on histological examination of their reproductive elements (oocytes, embryos and larvae). Theonella swinhoei, T conica and T. aqabaensis were shown to be oviparous, whereas H. arabica, A. chloros, and Siphonochalina siphonella are viviparous, as is also known for N. rowi and C. paralia.