Syllis hyalina Grube, 1863

Typosyllis hyalina: Imajima, 1966b: 271 –273, Fig. 57 a–k; Hartman, 1968: 487 –488, Fig. 1–3; Gardiner, 1976: 140, Fig. 12 v –w; Fauchald & Reiner, 1975: 84; Fauchald, 1977: 22; Kudenov & Harris, 1995: 87 –89, Fig. 1.34.

Syllis hyalina: Monro, 1933: 30 . Rioja, 1941: 692; Berkeley & Berkeley, 1948: 74, Figs 107–108; López et al., 1997: 63; Capa et al., 2001: 112; San Martín, 2003: 426–429, Figs 234–235.

Material examined. 24 specimens (CPICML PO-37-051): 6 specimens, Caleta E1B1, 16°49.797’N, 99°54.062’W, 25 May 2006, 12 m, coarse sand. 15 specimens, Caleta E1B2, 16°49.797’N, 99°54.062’W, 25 May 2006, 12 m, coarse sand. 2 specimens, Palmitas E2B1, 16°49.420’N, 99°54.733’W, 25 May 2006, 10.5 m, coarse sand. 1 specimen, El Jardín E3B2, 16°49.436’N, 99°54.981’W, 26 May 2006, coarse sand.

Comparative material examined. Syllis hyalina, 1 specimen (MNCN 16.01/2472) SPAIN: Mediterranean, between Cabo de San Antonio and Valencia Port. Syllis hyalina, 2 specimens (MNCN 16.01/8136) CUBA: Caribbean, Canarreos Archipielago, Pinos Island, between Punta del Este and Cayo Matias, 4 m.

Remarks. The specimens differ from the Mediterranean and Cuban ones in having shorter and thicker dorsal cirri (with 3–6 articles instead of 7–9). Furthermore, the Mediterranean specimen has longer anterior falcigers and a single straight acicula, while the Cuban and Acapulco ones show a distally oblique acicula. Since the Acapulco specimens are more similar to the Cuban ones, there may be a species complex; this would need molecular studies to be resolved.

Habitat. Hard bottoms in the littoral zone, less abundant in soft bottoms.

Distribution. Cosmopolitan; but probably a species complex.