02791nas a2200265   4500008004100000022001400041245007600055210006900131260002900200300001400229490000800243520200700251653001602258653002002274653001302294653001102307653001302318653001202331653002702343653003202370100002102402700002702423700002002450856005502470       2011                        eng d  a1096-364200aSwima (Annelida, Acrocirridae), holopelagic worms from the deep Pacific0 aSwima Annelida Acrocirridae holopelagic worms from the deep Paci  bBlackwell Publishing Ltd  a663–6780 v1633 a<p>Two new species of Swima, a recently established genus of annelid worms, are introduced, one from deep water off the North American West Coast and the other from the Philippines. The acrocirrid genus now contains three named species, Swima bombiviridis, Swima fulgida sp. nov., and Swima tawitawiensis sp. nov.Swima are holopelagic, occurring only in the water column, and thus far have only been observed below 2700&nbsp;m. The worms are relatively large, sometimes reaching over 30&nbsp;mm in length and 5&nbsp;mm in width. They have gelatinous bodies and fans of long swimming chaetae, which are flattened into paddles in S. tawitawiensis sp. nov. Members of Swima are distinguished from other swimming acrocirrids by their transparent bodies, single medial subulate branchiae, and simple nuchal organs that do not skirt the bases of lateral subulate branchiae. Swima fulgida sp. nov. is distinguished from other members of the genus by its darkly pigmented anterior gut, whereas S. tawitawiensis sp. nov. is distinguished by possessing three subulate head appendages instead of just one and by the shape of its noto- and neurochaetae. Swima species possess four pairs of elliptical, transformed segmental branchiae that produce green bioluminescence when autotomized. These &lsquo;bombs&rsquo; were observed in various states of regeneration on a single individual. Swima are neutrally buoyant, often observed hanging immobile in the water column, and are active, agile swimmers. Although not previously documented in the literature, these worms are not rare in the deep water column. Since the worms were first noticed in 2001, they have been observed on more than half of the Monterey Bay Aquarium Research Institute&rsquo;s midwater remotely operated vehicle dives that went to sufficient depth. The discovery of Swima underscores our lack of knowledge of deep pelagic fauna.&copy; 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 163, 663&ndash;678.</p>
10aCelebes Sea10aCirratuliformia10adeep-sea10agelata10amidwater10apelagic10aSwima fulgida sp. nov.10aSwima tawitawiensis sp. nov1 aOsborn, Karen, J1 aHaddock, Steven, H. D.1 aRouse, Greg, W.  uhttp://dx.doi.org/10.1111/j.1096-3642.2011.00727.x