Behavior
One of the most fascinating features of the gastropterids is their swimming behaviour. The genus name Gastropteron can be loosely translated as "winged stomach", which is quite apt. Like most opisthobranchs, they are normally benthic crawlers, but when disturbed they can vigorously flap their greatly enlarged parapodia and remain suspended in the water column for some minutes.References:
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http://www.seaslugforum.net/find/sagornathttp://bie.ala.org.au/species/urn:lsid:biodiversity.org.au:afd.taxon:34bd5bcb-e018-4fd7-b81e-9ef8bb3aa613#overview