I’m not really ‘clued up’ on bivalves, but there are a lot on the rock platform, washed up in pieces on the beach and even living under the sand or mud (razor clams, ouch!), so I probably should get to know them. Here’s a first effort.
The one below is half of a jingle shell (Anomia trigonopsis).
Then there’s this live one detached from its moorings on the rock platform – possibly the spotted pearl oyster, Pinctata maculata.
If it really is this species, it may have had a pearl inside! But I’d rather throw it back in the water, which I did, to give it a chance to live.
Here’s an angel’s wing, half of the bivalve, Pholas australasiae.
Some bivalves attach themselves to a surface, and some bury themselves in the sand. They filter water of nutrients – small organisms or decaying ones.
Some can swim quite fast, as I witnessed when I added some bivalves to a tank with an octopus in it. Oh dear – mass panic from the bivalves and a gleam in the hungry octopus’s eyes! Some bivalves can detect light (scallops have relatively complex eyes) but most of their information about what’s around them comes in chemically. Wonder what octopus drool is like? Something nasty, if you believe bivalves!