A Chiton ?

[smb2]

Photo taken in 10 ft of water in Curacao N.A.
A POed Damsel fish was carrying this away from it's territory and dropped it on the sand.
I picked it up and got a slight sting on my palm. It was somewhat flexible and had a flat foot.
It could move like a snail at at fair speed (for a ? Chiton).

[Leslie Harris]

Sure is. It might be Acanthochitona hemphilli. Those are usually reddish brown with the clumps of spicules at each side of the plates, and the girdle usually covers nearly all of the plates. Acanthochitona species are common in the Caribbean.

[scottg]

Leslie, are there Chitons that can move at a noticeable speed when they put their mind to it? I thought they all sort of stayed put.

[Leslie Harris]

The intertidal ones tend to stay in one place during the day & move about at night. In fact, some will create a home depression in rock that exactly fits their bodies. That helps retain their body moisture & underlying water during low tides as well as give them a better hold against predators. This is the only measurement of speed I found in a quick search -- "31 chitons moved at an average speed of 0.24 cm/min on outward trips, with 3 cm/min the fastest recorded speed (Thorne 1967)" That was on food foraging trips; they may move faster when a predator is around.

[smb2]

Well this Chiton set a water speed record, in the Damsel's mouth. They are pugnacious little fish and don't like anything around their well kept algae garden. The Chiton was shown the door at a rather rapid speed

Thanks for the follow up.