But old, brown, even rotting veggies are even better, if you live in the intertidal zone. A blade of decayed eelgrass is a gourmet dish, if you're a hermit crab. Or an amphipod.
And they make a good nursery for babies just starting out into the wide world; the food underfoot is puréed already, the tough fibers and skins gone. Easy munching!
That's what I think happened here:
|Five abandoned egg cases. There may be a baby or two still deciding to leave.|
I don't know what animal laid these; I don't recognize the form of the cases. It's probably a snail, but not one I can identify.
The fuzzy stuff is a mass of diatoms, or possibly bacteria. A hermit crab will be along soon enough to clean all that out, leaving only the empty egg cases.
And there's more! I'm puzzling over a batch of green teeth. I'll post them tomorrow.