IMIS

This database is devoted to all echinoid species inhabiting ocean areas south of 35S latitude (Echinodermata: Echinoidea). Echinoids are well represented in the Antarctic benthic communities in terms of frequency, abundance and species richness. They are frequently collected both at shallow depths over the continental shelf and in deeper waters of the continental slope and ocean basins. With 82 species ever described that represent about 10% of echinoid species worldwide, the Southern Ocean is particularly rich in echinoid species. The Antarctic echinoid fauna is characterised by a relative high morphological diversity and high rate of endemism (66% of species - David et al. 2005b). It should be noticed that Antarctic echinoid diversity is represented by a few orders (7) among which the two orders Spatangoida and Cidaroida include 64.6% of Antarctic species. As a comparison, South Australian and New Zealand areas comprise 113 echinoid species, 62 genera and 12 orders, while southern South America only 36 species, 23 genera and 8 orders, and the Southern Ocean 82 species, 30 genera and 7 orders. Identifications and taxonomic accuracies were based on Mortensen, T. (1928, 1935, 1943, 1950, 1951) and David et al. (2005b).

The sampling area ranges from 35°S to 71°S latitude and from 180° W to 180°E longitude. The 35°S limit is coincident with the position of the Subtropical Convergence (Tchernia, 1980; Knox, 1983), which is considered to determine the limit between tropical and cold temperate marine species. The latter species were considered in the database, as they are likely to interact with Antarctic species in the future according to scenarii of forthcoming global climate change or to have interacted with them in the past.