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Re: Red Rock Crab Behavior Question

Posted: Mon Feb 06, 2017 1:10 pm
by dtodd
Mpenders
That was at the Junkpile last February 13th. A couple of octo researchers have weighed in on it and believe it to be an attempted cannibalism event.

Re: Red Rock Crab Behavior Question

Posted: Mon Feb 06, 2017 12:47 pm
by dtodd
Thanks Greg!

Re: Red Rock Crab Behavior Question

Posted: Sun Feb 05, 2017 2:59 pm
by Greg Jensen
Her eggs are recently extruded (orange) so nowhere near ready to hatch, and wouldn't be doing it in this position anyway.

I can see she has some large barnacles on her- my guess is that she somehow got flipped over and is so top-heavy from barnacles she couldn't right herself, and is too tired from trying to still be kicking.

Re: Red Rock Crab Behavior Question

Posted: Sun Feb 05, 2017 12:46 pm
by H20doctor
i would say that crab is 99% on the way out of life ... the fact its upside down and not moving means its sick and dying ... if you look at the behavior of a crab , either a red rock or a dungee .. crabs are either in the sand hiding, or out and about walking and eating .. when you approach a crab they go into defensive mode and run off , or throw up some pinchers to say " Hey Back Off !! "

Re: Red Rock Crab Behavior Question

Posted: Sat Feb 04, 2017 12:56 pm
by mpenders
I'm no crab expert, and didn't stay at a Holiday Inn Express last night - so I'm out.

However, the link at the end of your vid to your GPO Interaction vid looked interesting....



Wow! Way cool encounter. When & where did this happen?

Re: Red Rock Crab Behavior Question

Posted: Sat Feb 04, 2017 8:11 am
by YellowEye
Very interesting.
I think I've seen them (at least other crabs) release eggs whilst standing up before. And they twitch down there as they do.

Re: Red Rock Crab Behavior Question

Posted: Sat Feb 04, 2017 8:11 am
by ScubaJess
Very fascinating! I hope she's ok :)
Did you see any sea spiders?

Red Rock Crab Behavior Question

Posted: Sat Feb 04, 2017 7:55 am
by dtodd


Found this upside down gravid red rock crab at the Junkpile a few weeks back
As you can see from the video her mouth parts are moving and there is an occasional movement in her legs. I observed her for several minutes and there was no change in the behavior pattern.
What is going on here?
Is she dying?
Getting ready to for her eggs to hatch?

I sure wish there was a crab expert on this board. :) Greg Jensen?