Scaphopod mollusks from the Atlas V expedition (continental shelf of Jalisco and Colima, Mexico) on board of the R/V El Puma [Moluscos escaf�podos de la campa�a Atlas V (plataforma continental de Jalisco y Colima, M�xico) a bordo del B/O El Puma]

The distribution and abundance of 15 scaphopod species collected in the continental shelf off Jalisco and Colima, Mexico, in August 1988 were analyzed. Scapohods were collected with a geological Van Veen dredge in eight sampling stations at depths from 23 to 75 m in medium sand, sandy silt and silty clay substrata. A total of 222 individuals belonging to four genera and two families were recognized. The highest abundance was recorded between 72 and 75 m in silty clay substratum. The eight most abundant species represented 86% of all individuals: Fustiaria splendida (21.3%), Dentalium neohexagonum (16.7%), Cadulus perpusillus (11.3%), C. fusiformis (10.4%), D. sp.2 (8.6%), C. albicomatus (5.9%), F. brevicornu (5.9%) and D. sp.1 (5.9%). The Bray-Curtis ordination analysis allowed the recognition of three groups responding to the distribution and abundance of species, and to the influence of environmental factors of which salinity and depth were the most important in this analysis