Always something new

The tiny six-armed starfish was eating barnacles at the front of the aquarium, so I thought I could get a clear photo of all his equipment; gills and biting pedicellaria and questing tube feet and all. I was hoping to see how they compared to the tool chest of a mottled star.

Star and barnacles. He is about 1/2 inch eye to eye.

The mottled star's spines form definite lines along the centre of his arms. Like so:

Mottled star, out of the water, looking at me. (The eyes are those two red spots on the tips of the arms.)

Six's spines seem to be scattered almost randomly. They are white on the pale outer arms, and orange on the central star pattern. The gills are fat, translucent posts clustered mainly in the centre, although some of the shorter ones could possibly be pedicellaria; their tips are split, like those of the mottled star, but they're much bigger in proportion to the spines.

I couldn't see the ocelli (eyes), nor the tube feet.

But there was a surprise; in these photos, the madreporite, the intake valve on one side of the central medallion, turned out to have a circular fan-like structure in the opening, like the intake on the bottom of my computer.

The madreporite, slightly highlighted.

Six, two hermits, and barnacles. These are small barnacles; the hermits are even smaller.

I wanted a better look, so I removed the barnacled shell from the tank, with Six along for the ride. Immediately, all his varied skin ornaments went flat and inert. I'll have to try another tactic.