Benthic decapod crustaceans associated with captures of &lt;i&gt;Munida&lt;/i&gt; spp. (Decapoda: Anomura) in the Beagle Channel, Argentina

Gustavo A Lovrich,M Carolina Romero,Patricia Pérez Barros,Federico Tapella,Javier A Calagno

doi:10.3989/scimar.2004.68n2237

Abstract

Benthic decapod crustacean assemblages in the Beagle Channel are dominated by the galatheid crabs Munidasubrugosa and Munida gregaria. This study deals with the bathymetric and spatial distribution, density and diversity of the assemblage of decapod species that co-occur with Munida spp. in the Beagle Channel. A total of 131 samples were obtained using an epibenthic trawl from February 1999 to December 2000. They were taken monthly from two depth strata separated by the 40 m isobath (range: 4-262 m), and from three different sites: Bahia Lapataia, Ushuaia and Punta Segunda. Sixteen of the 36 recorded species of decapod crustaceans from the Beagle Channel were caught. Munidasubrugosa and M. gregaria contributed 94% to the total decapod material. Of the remaining 6%, Austropandalusgrayi (Caridea) was the most abundant species, constituting 43% of the non-galatheid decapod fraction. Some species, namely Paguruscomptus and Eurypodius spp., were characteristic of shallow waters ( 40 m). The average density and diversity of non-galatheid decapods varied with depth and location. Decapod diversity correlated positively with the density of algae and polychaete tubes. The influence of three-dimensional bottom structure on decapod diversity in the Beagle Channel is discussed.

Highlights

The Beagle Channel is located in southernmostSouth America and constitutes a key environment for the study of interactions between the sub-Antarctic region and the Antarctic
From the Magellan region to Antarctica, there is a sharp decline in key benthic groups such as crustaceans (Crame, 1999)
These studies were aimed at finding differences within the Magellan region, and among the diverse environments represented by the different channels and fjords

Summary

Introduction

South America and constitutes a key environment for the study of interactions between the sub-Antarctic region and the Antarctic. Gorny, 1999; Retamal and Gorny, 2001) These studies were aimed at finding differences within the Magellan region, and among the diverse environments represented by the different channels and fjords. In this region, five species assemblages were identified, in which the specific composition is explained by water depth, the presence of soft sediment and the occurrence of biogenic debris (Gutt et al, 1999)

Objectives

Methods

Results

Discussion

Conclusion