All the little mouths

They bite.

Close view of a starfish's busy coat.

Solid white spines, translucent gills, and the biting pedicellariae; all those little open jaws.

I've been spending time sitting in front of the tank, chasing an annoying white crab, and noticed interactions between the mottled star and the other residents. The starfish wanders about slowly, minding his own business (finding something more to eat), ignoring anything not edible. He can afford to be complacent; he's wearing his own security guard.

A hermit crab passes him, and touches - just barely - an arm of the star, and immediately yanks away his pincer and backs off. The little annoying crab swats at anything that comes near him, like a kitten does. Unless it's the starfish. He raises a pincer to hit it, remembers, changes his mind, and goes to hide under a shell.

I watched as a few grains of sand fell onto the back of the starfish. They immediately started to move up over the arm, and off the other side.

The pedicellariae are at work.

More on the crab, later. I'm trying to get a photo of the shape of his carapace, but I'm sure he recognizes the camera already; he runs away as soon as he sees it.

 

Cuddly

It's amazing, sometimes, how such a voracious, efficient killing machine as a starfish can look so huggable.

Leading arm of hunting mottled sea star. Baby blues and soft pinks, for extra innocence.

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.

Three arms and a half.

A month ago, the 25th of May, I brought home a three-armed starfish and posted his photo here.

3/5 of a star, an inch eye to eye. (The eyes are on the tips of the arms.)

I kept him in a hospital bowl for a week, and he seemed to be doing well, so I transferred him to the tank, where he went into hiding under a shell for another week. Now, he's out most days, eating barnacles and growing a leg.

And just look at him now! Fat and happy, and a little more balanced. An inch and a half eye to eye.

I don't see any buds for a fifth arm. I wonder if he's going to stop at four, or will start on the fifth when #4 is full size.