Distribution of the Polychaete assemblages on the continental shelf of the Northern Gulf of California, Eastern Pacific

Abstract

This study was aimed at analyzing the effect of environmental factors on the composition and distribution of polychaetes in the continental shelf of the Northern Gulf of California. Twelve stations at depths from 30 to 106 m were selected as representative of the region. A total of 2510 polychaetes belonging to 33 families and 152 species were identified. The Spionidae (15 species), Lumbrineridae (11 species), Onuphidae and Cirratulidae (10 species each) were the families with the highest number of species, although only the spionids (96.29 ind./0.1 m 2 ) were found in considerable densities. Distribution of the assemblages clearly reflected the influence of sediment type. The polychaete fauna was divided in two main groups: those distributed in sandy sediments and those found in sediments with higher mud content. The sandy assemblages were represented by the Phyllodoce sp. 1 group, distributed in the outer continental shelf to the south of the study area; the Aglaophamus verrilli, Chone sp. 1 and Spiophanes duplex group, which was found on the inner and middle shelf; and by Prionospio (P.) ehlersi, Chaetozone setosa, Monticellina dorsobrachialis and Leiocapitella glabra, a group located in the deeper zones of the northern coasts. The assemblages associated with muddy-sand bottoms were mainly characterized by Paranaitis sp. 1, found on the eastern coasts, and by the fauna distributed in the western region, where Scoloplos texana was the most common species.

Benthic Community Assessment of Commercial Oyster (Crassostrea virginica) Gear in Delaware Inland Bays

“…One factor that may have contributed to the significant difference is the variations in the characteristics of bottom substrates. Generally, bottom type, sedimentation rate, depth, sediment temperature, total organic matter, oxygen level, and pollution are named to be key local factors explaining the spatiotemporal distribution of benthic fauna, including polychaetes [103]. Sediment texture and organic matter content are akin in RB and IR, mostly consisting of thick mud [60] enriched with a high level of organic matter [64].…”

Depth diversity profile of polychaete worms in Bahía Chatham, Isla del Coco National Park, Costa Rican Pacific

“…Most of the studies published are taxonomic description and catalogues of tropical regions, for example the Galápagos (Treadwell 1928, Berkeley & Berkeley 1939, Westheide 1974, Central America (Chamberlin 1919, Hartman 1959, Dean 2009), Coiba (Aguado & San-Martín 2006), the coast of Panamá (Monro 1928, Fauchald 1977, and Mexico (Berkeley & Berkeley 1939, de León-González et al 2009. The ecology of polychaetes is poorly known in subtidal habitats of the tropics (Alongi 1990) with the most recent works conducted in Mexico (Hernández-Alcántara & Solís-Weiss 2011).…”