Synopsis of the pycnogonids from Antarctic and Subantarctic waters

Abstract

This work summarizes existing knowledge on the faunal history, biodiversity and biogeography of the Antarctic and Subantarctic pycnogonids. It refers to material sampled between 1829 and 1999 from more than 40 expeditions run by 14 countries, and published in 75 papers. Up to now, 31 genera and 25 species have been recorded from a total of about 38,000 specimens captured at 2,000 stations. They constitute 38.75% and 21.5%, respectively, of the 80 genera and 1,164 species recorded worldwide. One hundred and twenty species have been found in Antarctic, 71 in Subantarctic waters, and 60 species in both zones, yielding an endemicity for the entire area of over 80%. Fifty ®ve species revealed a circumpolar distribution and 161 were found mainly on the shelf. The Antarctic Ocean is suggested to be a centre of pycnogonid speciation and dispersion.

Cryptic mitochondrial lineages in the widespread pycnogonid Colossendeis megalonyx Hoek, 1881 from Antarctic and Subantarctic waters

“…Hence, our data do not support that Colossendeis megalonyx has its historic origin on the South American shelf and colonized the Antarctic subsequently. Our data show that clade B obtains a derived position within the Antarctic clades, suggesting a scenario of Antarctic radiation of nominal Colossendeis megalonyx and a subsequent expansion to Subantarctic and temperate regions which has been postulated earlier for several pycnogonids (Arnaud 1987;Hedgpeth 1969;Munilla 2001) and also for other Antarctic taxa (see Wilson et al 2009). A more complete data set comprising samples from other regions of the Antarctic is needed to clarify the routes of colonization of the Antarctic shelf.…”

Biodiversity and biogeography of Southern Ocean pycnogonids

“…The Antarctic pycnogonid fauna appears to be more diverse compared to that at lower latitudes; 20% of the total species known are found in Antarctic and/or Sub‐Antarctic waters, possibly being the most speciose area for pycnogonids in the world (Munilla and Soler‐Membrives 2009). Comparing the percentages of known living species on a global scale, it has been suggested pycnogonids are better represented around Antarctica than speciose groups such as polychaete worms (~12%), amphipods (~8–14%), echinoderms (4.9%), Porifera (6.2%), fish and gastropod molluscs (<2%) (Munilla 2001, Barnes and Peck 2008). In contrast, for many other groups e.g.…”

“…Hedgpeth in particular, used these distributions in efforts to define biogeographic patterns or provinces within the Southern Hemisphere. The most recent studies (Munilla 2001, Griffiths et al 2009, Munilla and Soler‐Membrives 2009) analyse pycnogonid distributions based upon species lists accumulated from the literature for predefined regions based upon geographic, maritime or political boundaries.…”

Distribution of sea spiders (Pycnogonida, Arthropoda) off northern Norway, collected by MAREANO

“…A sharp megafaunal discontinuity has also been found around 1300 m for the Porcupine Seabight, probably due to outflow from the oxygen minimum layer of the Mediterranean (Lampitt et al 1986). Munilla (2001) recorded fewer pycnogonid species below 1000 m depth in the Antarctic. We found a decrease in species and a fauna change below 800-900 m depth.…”