Meeting Abstract
Sea spiders (pycnogonids) are a small group of exclusively marine arthropods which resemble terrestrial spiders. One family, the Colossendeidae can grow to a very large adult size, much larger than any other pycnogonid. Colossendeis colossea, the largest known species, has a leg span of up to 70 cm and is found in both very deep ocean waters and shallower water in the Antarctic. Since it has been very difficult to obtain and study live specimens of this species, very little is known of their biology and natural history. We have obtained a number of preserved specimens, all labeled C. colossea, from the United States National Museum and are asking the question, are all of these specimens actually C. colossea? To answer this question, the specimens are being compared to syntypes from the Museum of Comparative Zoology and also to the original type description (Wilson, 1881). Based on previous scientific papers on C. colossea and closely related species, the following are used to separate species within this genus: relative proportions of terminal segments of walking leg and of pedipalp; location and number of eyes and shape of eye tubercle; proboscis shape and orientation; number of spine rows on terminal segments of oviger and shape of oviger terminal claw; abdomen size and orientation. Based on these, our preliminary results demonstrate that some of the United States National Museum specimens are not C. colossea since they differ from the syntypes and type description in several of the above characteristics.
