The tanaidacean fauna of the Beagle Channel (southern Chile) and its relationship to the fauna of the Antarctic continental shelf

Abstract

In November 1994 epibenthic sledge samples were taken in the Beagle Channel. This study presents the first systematic account of Tanaidacea of the Beagle Channel and an adjacent area on the Atlantic continental slope. The material of this part from the Magellan Strait comprised 2175 specimens and 27 species of eight families of Tanaidomorpha and two families of Apseudomorpha. Eleven species were sampled in the Magellan region for the first time. The genus Stenotanais (Anarthruridae) was reported for the first time in the Southern Hemisphere and, the bathymetric range of seven species was extended. The tanaidacean fauna in the Beagle Channel is highly heterogeneous with 36 tanaidacean species now known from the Magellan region. On the basis of a zoogeographic comparison of the Magellan region with sub-Antarctica and Antarctica, Sieg's (1988) hypothesis of a phylogenetically young, derived Antarctic tanaidacean fauna is examined and the zoogeographic relationship between the Magellanic Tanaidacea and the Antarctic tanaidaceans is discussed.