Inter-population variability and character description in the sponge associated Haplosyllis spongicolacomplex. (Polychaeta: Syllidae)

Abstract

Haplosyllis spongicola is probably the most representative symbiotic syllid harboured by sponges and has been widely reported from tropical, subtropical and temperate seas. Its external morphology seems to be very well adapted for its life-style, with all chaetae being simple and having two small teeth and a large main fang. However, the species has been the subject of a long-lasting taxonomic controversy, which gave rise to more than 15 synonymies, with hundreds of records worldwide. The present paper is based on the study of more than 28 populations obtained from around the world. These populations have been carefully analysed using different approaches (morphometry, morphology and biology). As a consequence, the existence of a pseudo-sibling species-complex within the socalled cosmopolitan H. spongicola has been revealed. The most relevant characters (as well as their variability) that will allow a future identification of the species involved in the complex are fully described, illustrated and analysed.