Proceedings of 

 the United States 

 National Museum 



SMITHSONIAN INSTITUTION • WASHINGTON, D.C. 



Volume 121 1968 Number 3650 



Loxosomella from Tedania ignis, 

 the Caribbean Fire Sponge 



By Klaus Riitzler 

 Associate Curator, Division of Echinodernts 



Although several species of Loxosomella — in fact, most of those 

 hitherto referred to the abandoned (Nielsen, 1964) genus Loxocalyx 

 Mortensen — live on the surface or in the canal systems of sponges, 

 they are not encountered too commonly. If not particulary searched 

 for, single specimens can be overlooked easily when one is collecting 

 and studying sponges. In two instances, however, mass colonization 

 of Loxosomella has been observed in the tropical west Atlantic <>n 

 Tedania ignis (Duchassaing and Michelotti), the fire sponge. 



While collecting sponges in April 1967, I took one specimen of 

 Tedania ignis from pilings of the south boat dock of the marine 

 biological laboratory on Magueyes Island, off La Parguera, Puerto 

 Rico. A conspicuous, fluffy, whitish coating on the sponge surface 

 turned out to be a dense layer of Loxosomella bimaculata, new species, 

 described herein. An average of 500 specimens per cm 2 was counted, 

 with a total of almost 100,000 specimens on a host sponge twice the 

 size of a human fist. Strewn among them were a few dozen specimens 

 of a taller, brownish species described herein as Loxosomella par- 

 guerensis, new species. The examination of other sponge species 

 growing nearby did not reveal loxosomatids of any kind. 



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