Sea zucchini.

[ptychoptera]

When I collected these guys I thought they were sipunculans or priapulids... then when I got home I saw some tube feet sticking to the bowl I photographed them in. The best identification I can find is Holothuria lineata.

The closeup is of the anterior.

Anyone care to take a stab at it? Leslie, know any echinodermatologists?

NOTE: size on these are around 3 inches, extended. Though I collected some 2X-3X this size.

 

[LeslieH]

Yes, I do. There's a fellow in Saipan by the name of John Starmer who's good & who's also familiar with Hawaiian cukes. We were together on a research cruise to French Frigate Shoals last year. Alex Kerr at the University of Guam is another one for the area.

Do you know about the Guam invert image website? Here's the holothuroid portion of it. There's a fair amount of overlap between Hawaii & Guam so it will be useful for you.
http://www.flmnh.ufl.edu/reefs/guamimg/echinodermata/holothuria/index.html