Marine and brackish-water molluscan biodiversity in the Gulf of California, Mexico

Abstract

SUMMARY: A database containing taxonomic, distributional and ecological data of 2194 species of marine molluscs (1528 Gastropoda, 565 Bivalvia, 59 Polyplacophora, 21 Scaphopoda, 20 Cephalopoda, and one Monoplacophora) known to the Gulf of California, Mexico, was used to analyse their latitudinal and bathymetric distribution, to define their substrate preferences, and to elaborate a biodiversity model for the study area. The model was based on a comparison between the set of data associated with each species (i.e., depth range, associated substrates and geographic distribution within the Gulf) and the environmental conditions prevailing in the Gulf (i.e., depth and substrate), using a georeferenced grid of 2 × 2 nautical miles. Results are presented as predictive biodiversity distribution maps for the major molluscan groups. Putative biodiversity ranges were defined using a percentage accumulative system with 20% classes. As expected, the highest biodiversity occurs along the coastline and around the islands. A south-north biodiversity gradient is observed, although it is less evident between the southern and central Gulf.Keywords: Mollusca, biodiversity, Gulf of California, Mexico. RESUMEN: BIODIVERSIDAD DE LOS MOLUSCOS MARINOS Y DE AGUAS SALOBRES EN EL GOLFO DECALIFORNIA, MÉXICO. -Una base de datos conteniendo información taxonómica, de distribución y datos ecológicos de 2194 especies de moluscos marinos (1528 Gastropoda, 565 Bivalvia, 59 Polyplacophora, 21 Scaphopoda, 20 Cephalopoda y un Monoplacophora) conocidos para el golfo de California, México, fue utilizada para analizar su distribución latitudinal y batimétrica, para definir su afinidad por los distintos substratos, y para elaborar un modelo de la biodiversidad para el área del estudio. El modelo fue basado en una comparación entre el sistema de los datos asociados con cada especie (i.e., intervalo de profundidad, substratos asociados, distribución dentro del golfo) y las condiciones ambientales (i.e., profundidad y substrato) prevalecientes en el golfo, usando una retícula georeferenciada de 2 × 2 millas náuticas. Los resultados se presentan como mapas de distribución de la biodiversidad para Bivalvia, Gastropoda, y para el resto de los grupos. Las gamas supuestas de la biodiversidad fueron definidas usando un sistema acumulativo del porcentaje con las clases del 20%. Según lo esperado, la biodiversidad más alta se encuentra a lo largo de la línea de la costa y alrededor de las islas. Se observa un gradiente de la biodiversidad del sur-norte, aunque es menos evidente entre la parte sur y central del golfo.Palabras clave: Mollusca, biodiversidad, golfo de California, México.

Species composition, richness, and distribution of marine bivalve molluscs in Bahía de Mazatlán, México

“…The high marine biodiversity of Golfo de California has been related to its irregular coastal geomorphology (i.e., open and protected bays and inlets, rocky and sandy beaches, estuaries, and numerous islands), the local dynamics of the surface currents and the seabed heterogeneity (Hendrickx and Brusca 2002, Hendrickx et al 2005). According to Roy et al (2000), there is a remarkable increase in infaunal and epifaunal bivalve species in the northeastern Pacific coast, between latitudes 5°N (i.e., Punta Paita, Perú) and 23°N (i.e., Bahía de Mazatlán, México).…”

“…The following references were used for the taxonomic identification of bivalves: Abbott (1974), Keen (1971), Morris (1980), and Coan and Valentich-Scott (2012). Previous inventories, additions, and taxonomic changes which include records from Bahía de Mazatlán were also reviewed (Parker 1963, Keen 1971, Orozco-Romo 1980, Arreguín-Romero 1982, Sánchez-Vargas 1984, Skoglund 2001, Olabarria et al 2001, Hendrickx et al 2005, Camacho-Montoya et al 2007, Rendón-Díaz 2010, Coan and Valentich-Scott 2012). …”

The Pinnotheridae of the northeastern Pacific (Alaska to Mexico): zoogeographical remarks and new bivalve hosts (Crustacea, Brachyura, Pinnotheridae)

“…The range extension and new hosts recorded herein, along with new records and new species of pinnotherid crabs described in the past few years for the tropical Pacific (Campos 2013;Campos & Vargas-Castillo 2013;Ayón & Hendrickx 2014;Salgado-Barragán 2015) strongly indicate that much more fieldwork and taxonomic study is needed to obtain a better idea of the species diversity of these inconspicuous crabs in this region. Assuming that diversity increases from north to south (see, Hendrickx et al 2007), it is expected that the actual number of pinnotherids in the subtropical-tropical Mexican Pacific could be higher than that of the Aleutian, Oregonian, and Californian provinces and not so similar as is now known. Species diversity would be higher if the species endemic to the Gulf of California are added to those in the subtropical and tropical Mexican Pacific.…”

Distribution of Gastropoda and Its Relation With Environmental Characteristics in Coastal Waters of Nusalaut Island, Central Maluku

“…Karakteristik substrat ini memungkinkan ditemukannya jenis Gastropoda yang bersifat infauna maupun semi-infauna. Menurut Hendrick et al (2007), moluska memiliki sifat infauna atau semi-infauna yang mendiami habitat berpasir dan berlumpur di kawasan pesisir sebagai penyusun komunitas makrozoobentos. Biota moluska juga merupakan salah satu komponen utama di komunitas sedimen lunak di kawasan pesisir.…”