A quick snorkel in the rockpools today. Tried to photograph some gobies and prawns but they were not very cooperative. I noticed a small clam under an overhang: the Variegated scallop Mimachlamys varia (old name: Chlamys varia). This species occurs quite commonly attached under rocks here, and although it can have all kinds of amazing purple, yellow and orange colours it is usually a dull brown. I managed a couple of OK shots; it is fun to see the rows of eyes. Definitely worth trying again (and going for a much bigger Scallop Pecten jacobaeus while diving should be fun too).
When it was very low tide last week, I decided to skip the ‘rock pools proper’ on my local beach in Flushing and to check out the zone just below where the rocks and the sandy bottom of Penryn River (an arm of the Fall Estuary) meet. All common rock pool inhabitants – winkles, top shells, edible crabs, worm pipefish and shannies – still live here, but some other organisms are more abundant here than in the rock pools.
In addition to sponges, I noticed quite a lot of the colony-forming ascidian Botrylloides leachi (see previous post). That explains why I could also find a couple of European cowries Trivia monacha, their predator. Also very common here are the Variegated scallop Chlamys varia and the Thicklipped dog whelk Hinia incrassata (top right picture). I am not sure what the slimy beige stuff is!
Very common were little Squat lobsters Galathea squamifera (no picture), rapidly swimming backwards to escape. Even more abundant were these little Hooded prawns Athanas nitescens:
The Variegated scallop Chlamys varia is quite common here; it is often purple, but it can be orange, red or yellow as well. Below a purple-red one I found under a rock covered in some Spirorbis spirorbis (calcified worms) and surrounded by Cushion stars, Grey and Flat top shells and Periwinkles:
A big one:
This scallop attaches itself to rocks with byssus threads but is able to move around quite a bit as well. I have had two in the aquarium for a couple of months, longer than any other bivalve I’ve tried, but in the end they died anyway. It is hard to keep filter feeders; algae tend to thrive in aquaria, but usually in their attached- rather than planktonic form. I have not had luck with tunicates either and I won’t try any new filter feeders until I have found a proper way to feed them. On one forum, I was recommended a form of artificial plankton that is commonly used for corals which could be interesting. However, this will require a lot of skimming to get rid of the non-eaten food. I’ll therefore focus on experimenting with seaweeds for now. Below two close-ups of a Variegated scallop in the aquarium. Scallops have rows of beady eyes along their mantle, this can be seen in the the second picture: