sea spider Ammothea sp., probably A. carolinensis

Ammothea carolinensis is found throughout Antarctica and the Antarctic Peninsula, Peter I Island, South Shetland Islands, South Orkney Islands, South Georgia Island, and Bouvet Island from depths of 3 to 670 meters [1,2,3,6,7]. A. carolinensis has a leg span about fourteen centimeters for males and eighteen centimeters for females [1].

A. carolinensis is the most common Antarctic species of its genus [1]. Ammothea species are found predominantly in Antarctic and subantarctic regions (19 of 31 known species); seven other species are known from the southern hemisphere and only five from the northern hemisphere [4]. Antarctic and subantarctic sea spiders comprise 251 species, representing 21.5% of worldwide species, with 101 species endemic to Antarctica and 60 endemic to subantarctic areas [5].

Sea spiders are exclusively marine and mostly bottom dwelling (benthic) [4]. Adult sea spiders either suck the juices from soft-bodied invertebrates or browse on hydroids and bryozoans. Male sea spiders carry cemented egg clutches gathered from females until hatching and often after hatching in the larval stages [4]. Since sea spider larvae are not planktonic, sea spider dispersal is slow and intermittent leading to the development of many endemic species among shallow-water sea spiders [4].

1: Antarctic and Subantarctic Pycnogonida : Ammotheidae and Austrodecidae. CA Child. Antarctic Research Series Volume 63, Biology of the Antarctic Seas 23. Washington DC : American Geophysical Union, 1994; 2: Fauna of the Ross Sea, Part 7. Pycnogonida, 1. Colossendeidae, Pycnogonidae, Endeidae, Ammotheidae. WG Fry & JW Hedgpeth. New Zealand Department of Scientific and Industrial Research Bulletin 198. New Zealand Oceanographic Insitute Memoir 49. 1969; 3: US National Museum Polar Invertebrate Catalog at www.nmnh.si.edu/iz/usap/usapdb.html; 4: Marine Fauna of New Zealand: Pycnogonida (Sea Spiders). CA Child. Wellington : National Institute of Water and Atmospheric Research, 1998. NIWA Biodiversity Memoir 109; 5: Polar Biology 24:941-945, 2001; 6: Antarctic Science 13(2):144-149, 2001; 7: Polar Biology 29(2):83-96, 2006

Ammothea sp., probably A. carolinensis (Leach, 1814) identification by Roger Bamber, British Museum of Natural History. Text ©Peter Brueggeman. Photograph ©Canadian Museum of Nature (Kathleen Conlan). Photograph may not be used in any form without the express written permission of Canadian Museum of Nature (Kathleen Conlan).