Check-list of the pycnogonids from Antarctic and sub-Antarctic waters: zoogeographic implications

AbstractThis study contains the current list of the austral pycnogonids together with details of their depth range and distribution. To date 264 species have been recorded, accounting for 19.6% of the 1344 species recorded worldwide. One hundred and eight species are endemic to Antarctic waters, 62 to the sub-Antarctic, 63 are common in both regions, and 55 are circumpolar. The richest genus isNymphon, with 67 species and the richest area is the Scotia Sea. Comparing species lists between the years 2000 and 2007 shows that increased expeditions with more sampling has increased the circumpolarity of species and decreased zonal endemicity. The benthic insular refuge hypothesis is proposed as an explanation for the southern distribution of the present pycnogonid fauna, with an origin in the Scotia Arc.