Sunday, June 9, 2013

Crabbing at Boundary Bay

The last time we visited Boundary Bay, I did see a few small dungenous crabs in the water, but we spent too much time in the shallower tide pools to look for the catchable ones.  Yesterday, we tried to get to water's edge by low tide (noon) to catch something for dinner.

It was just over a kilometre of walking to get to the water's edge.
https://maps.google.ca/maps/ms?msid=210247271623531636657.0004deac4ee208b13d515&msa=0&ll=49.010923,-123.0287&spn=0.012034,0.033023

We arrived just as the tide was ascending, but still saw many crab in the knee-deep tide pools.  Many that I found were embraced in  courtship:
 
A male finds a female who is suitable for mating, and grabs her tightly.  He locates a suitable female through chemicals in her urine, which signals that she is about to moult, or discard her old shell.  The female is only receptive to mating when her shell is soft, so the male will carry her around for a few days, fighting off potential suitors, and waiting until she moults.  He will further protect soft shell from predators.


Even after pulling him out of the water, he remains firmly grasping his much smaller partner.

I didn't see many nudibranch this time, but found other soft-bodied invertibrates, like this dead lion's mane jellyfish.

Most of you have never seen a clam move, but they're terrific diggers, considering they only have one appendage.

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