Abstract
The Loxosomatidae is the most species-rich of the four families belonging to the phylum Entoprocta, comprising more than two-thirds of the total number of entoprocts worldwide (Iseto et al. 2008). It comprises solitary forms, usually commensal, whereas the species of the other three families are colonial (Nielsen 2001). Members of this family and of the colonial family Loxokalypodidae can be distinguished from other entoprocts because they lack a star-cell complex at the transition between stalk and body (Nielsen 1989). Although loxosomatids can be found on a range of living and non-living substrata, sponges are common hosts for these animals and 17 entoproct species have been found inhabiting them (Iseto et al. 2008; Sánchez-Tocino & Tierno de Figueroa 2009b). Until now, only five valid species have been reported from sponges from the Mediterranean Sea: Loxosomella raja (Schmidt), L. cochlear (Schmidt), L. tethyae (Salensky), L. pes (Schmidt) and L. ameliae Sánchez-Tocino & Tierno de Figueroa (Prenant and Bobin 1956; Nielsen 2008; Sánchez-Tocino & Tierno de Figueroa 2009b). In the present paper, we describe a new Loxosomella species that lives on the sponge Hyrtios collectrix (Schulze) in the Alboran Sea (West Mediterranean Sea), where L. tethyae, L. pes and L. ameliae have been reported (Sánchez-Tocino & Tierno de Figueroa 2009a, b).
References
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