pelagic larvae in salp id

I found this little guy in very shallow water over the reef in Cirkewwa, Malta at night. It seemed to be some sort of crustacean larvae living in a salp 'shell' and he used his little tail to propel himself around at a good speed.

Any idea what it is?

(sorry for the blurry shots but it was only around 1cm long, transparent and moving way too quick for my little compact cam to focus well!)

Something like an Parathemisto amphipod.

Alex

From your second shot it looks like a Phronima. Here is a pic of a freeze-dried specimen I collected in the Gulf of Alaska. When it was fresh it was transparent. The mouth parts move a bit like that of an alien from the Alien movies. See: http://en.wikipedia.org/wiki/Phronima

bingo, thanks Tom, google brought up a bunch of pics under that name which looked just like it. Creepy little guys....