Sipunculida collected in July-August 2010 from the Wagner and Consag Basins in the northern Gulf of California were analysed. This is a region in the northern Gulf of California approximately 700 km2 in area, 59-217 m in depth, and with intense gas hydrothermal activity. Salinity, temperature, pH, and sediment type were also measured. Sipunculids were collected at 25 stations (five families, eight genera and eight species). Where no sipunculans were found (11 stations), more intense gas seepage and very low pH (6.06 to 6.48) prevailed. Densities were generally low in the study area (1 to 8 ind. 0.1 m-2), except at station W-2 (10 ind. 0.1 m-2), due to the abundance of Onchnesoma steenstrupii steenstrupii. The species with the highest frequencies were Golfingiidae sp. (15 ind. 0.1 m-2) and O. steenstrupii steenstrupii (33 ind. 0.1 m-2). The spatial density and frequency fluctuations of the Sipunculida species in the study area seemed to be related to sediment type, pH, depth, and temperature. Golfingiidae sp., Phascolion sp. and Apionsoma (Apionsona) sp. are new records for the area, while distribution is extended towards north up to the Wagner and Consag Basins while Aspidosiphon (Akrikos) albus and Onchnesoma steenstrupii steenstrupii are new for the Eastern Pacific.
Hermoso-Salazar M., Frontana-Uribe S., Solis-Weiss V., Prol-Ledesma R. M., Estradas-Romero A., 2013. The occurrence of Sipuncula in the Wagner and Consag Basins, Northern Gulf of California. Cahiers de Biologie Marine 54: 325 – 334. Article (subscription required).
