Examination of polychaete specimens from Haifa Bay (Israel, eastern Mediterranean Sea) revealed several individuals exhibiting morphological characteristics similar to Sphaerosyllis hystrix Claparède, 1863. A detailed morphometrical analysis of the Israeli specimens in comparison to specimens of Sphaerosyllis hystrix and Sphaerosyllis boeroi Musco, Çinar and Giangrande, 2005 supported the description of the former as a new species, Sphaerosyllis levantinasp. n. Individuals of Sphaerosyllis hystrix formed a very heterogeneous group with strong character variations in the analysis and the presumed cosmopolitan distribution of the species is discussed based on literature records.
Keywords: Cybertaxonomy; Exogoninae; Mediterranean; Polychaetes; Scratchpads; Sphaerosyllis; Syllidae; new species.