Here's an oddball pteropod that you won't encounter very often, even if you set your sights on finding one.  Little is known about this rare, inconspicuous species.  An inhabitant of deeper water, it occasionally can be collected near the surface with a plankton net.  The cylindrical body may reach a length of up to 2.5 cm, but is usually quite a bit smaller.  A pair of distinctive paddle-like wings extend out from the body at the mid-point.  These are used for swimming, but Thliptodon is no speed demon, being among the slowest of the pteropods.  There is no jaw or other appendages, but the buccal apparatus does possess a radula and large hook sacs.  Consider yourself lucky if you find a Thliptodon - few biologists have ever seen one.  

All photographs © David Wrobel and may not be used or copied without permission!