Gastropod mollusks from the continental shelf off Jalisco and Colima, Mexico: species collected with a trawl net

Abstract

This study examines the distribution and abundance with respect to depth and type of substratum of 86 gastropod species collected from the Pacific continental shelf off Jalisco and Colima, Mexico, in August 1988. Sampling was performed with a trawl net at 22 stations, at depths of 18 to 112 m. A total of 582 individuals pertaining to 42 genera, 25 families, 4 orders and 3 subclasses of gastropods were collected. Abundance of gastropods was similar between 18 and 83 m, but the number of live individuals decreased between 41 and 60 m. Deep (61-83 m) stations registered the lowest diversity; however, the number of species collected alive decreased with depth. No gastropods were collected at stations deeper than 83 m. The number of individuals and species also varied with the type of substratum. Greater heterogeneity of the sediments was found at the shallower stations (18860 m) with medium sand, sandy silt and silty clay substrata. The greatest number of species were collected at stations with sandy silt and medium sand substrata. Total abundance was notably smaller in medium sand, while the abundance of live gastropods was higher in silty clay substratum. The seven most abundant species represented 5 1.2% of all of the individuals. Most of these species are of commercial interest, in particular those of the genera Fusinus, Hexaplex, Ficus, Harpa, Cantharus and Bursa.

Species richness and biogeographical affinities of the marine molluscs from Bahía de Chamela, Mexico

“…However, it is not until recent years that detailed studies have been conducted on the marine biota. These studies truly sustain this recognition as an area of high marine biodiversity and coincide in pointing out that the high species richness is related to the coastal geomorphology and the heterogeneity of the seabed (Nuño-Hermosillo et al 2006. Certainly, in the bay, there is an important variety of habitats associated with islands, islets, cliffs, rocky reefs, aggregations of corals, rocky and sandy beaches that increase the heterogeneity and, thus, the availability of marine habitats and, therefore, the variety of benthic microenvironments.…”

“…The geographic distributions of each species were first reviewed in the specialized literature (e.g. Keen 1971, Hendrickx and Brusca 2005, Hermosillo et al 2006, Coan and Valentich-Scott 2012, Kaas and Van Belle 1985, Kaas and Van Belle 1985, Kaas and Van Belle 1987a, Kaas and Van Belle 1987b, Reyes-Gómez 2016, Steiner and Kabat 2004 and they were also supplemented or updated using additional bibliographic references for particular genera and species. Biogeographic affinities were then assigned and evaluated, based on the biogeographic regions proposed by Spalding et al (2007).…”

“…Taxonomic identification was performed using specialized literature: Keen (1971), Hermosillo et al (2006), Coan and Valentich-Scott 2012, Kaas and Van Belle (1985), Kaas and Van Belle (1985), Van Belle 1987a, Kaas andVan Belle 1987b), Reyes-Gómez 2016, Emerson 1962, Steiner and Kabat (2004. When necessary, additional bibliographic references for particular genera and species were also used.…”

“…During recent years, inventories performed in Bahía de Chamela have improved our knowledge of major marine taxonomic groups, including the resident seabirds of the islands and islets (Hernández-Vázquez et al 2010), the fish assemblages (Galván-Villa 2015, Galván-Villa et al 2016) and the parasites of several fish species (León et al 1997, Mendoza and Pérez 1998, Pérez-Ponce de León et al 1999. Amongst the invertebrates, most of this work has focused on echinoderms (Nuño-Hermosillo et al 2006, Ríos-Jara et al 2013 and crustaceans (Bastida-Izaguirre et al 2013, Ayón-Parente et al 2014, Ayón-Parente et al 2016. There are only two previous studies on the marine molluscs performed almost 20 years apart from each other reporting the most conspicuous species with a total of 49 gastropods, 10 bivalves and three chitons (Román-Contreras et al 1991.…”

Scaphopod mollusks from the Atlas V expedition (continental shelf of Jalisco and Colima, Mexico) on board of the O/V El Puma

“…Esto queda confirmado por el valor alto del coeficiente de the rest corresponding to gastropods and bivalves (Pérez-Peña and Ríos-Jara, 1998;López-Uriarte, 1989). Scaphopods also contributed in an important way to the mallusk species richness, with 25.4% of the species.…”