A new species of Sphaerosyllis Claparede, 1863 (Polychaeta: Syllidae: Exogoninae) from the Atlantida Tunnel, Lanzarote, Canary Islands

A new species of Sphaerosyllis (Syllidae, Exogoninae), S. iliffei n. sp., is described from interstitial habitats of Montaa de Arena in the Atlantida Tunnel, a marine lava tube of La Corona volcano (Lanzarote, Canary Islands). The new species is characterized by lacking eyes, parapodia bearing four heterogomph compound falcigers with blade lengths decreasing from dorsalmost to ventralmost, and one supra-acicular simple chaeta distally serrated from first chaetiger. Females brood eggs ventrally, attached juveniles occurs to chaetiger 12. Males have long ventral cirri from chaetiger 13 backwards, without natatory chaetae. Sphaerosyllis iliffei n. sp. is the first record of a troglobitic Syllidae, with its unpigmented body, the apparent absence of eyes, and the females ventrally brooding a single embryo.