Once again in June 2017 4 days before the full Moon most of the aggregating Spider Crabs in Portphillip Bay came in to the shallow water. . Why do they come in so shallow?
Its hoped that this video might give some answers to the evolutionary advantages of coming so close to shore to Moult. Gravity(climbing high as possible), rough choppy sea and very strong currents assist in speeding up the moulting process. Getting away from their old shell as quick as possible makes sense to me..Please comment
Spider Crabs Mass Moulting 2017
7 responses to “Spider Crabs Mass Moulting 2017”
it is interesting that the four days before the full moon has something to do with molting in Port Phillip. Thanks for remembering (and reminding the Ray too? 😉 ) and showing us again. always enjoy your videos
Wow
Very nice! If you need any free music for your content, come to my page
Nice video, but I don’t get how gravity is a factor. How does climbing as high as possible affect gravity? I mean, yes, gravity does decrease as you move upwards away from the dense core of the planet, but that is really completely negligible at the scales we’re talking about here.
I have 4 crab videos (under my full name on u tube) that might show crabs piled on top of each other and although not necessarily showing the moulting its not hard to imagine that if a crab did moult the weight of its body would assist in it leaving its shell. If you cannot find them I will send links.
I don’t see any instances of crabs piling up on other crabs in the video though. Are there any recorded instances of crabs utilising gravitational assistance to expedite moulting? The buoyancy afforded by being in water also will tend to offset the effect of gravity to some extent, I think. My gut feeling is that the effect of gravity, while present, will be negligible. I’d say strong and/or turbulent currents (which you also mentioned) would have a much greater impact.
Thanks for your comments, my point here is that as the Crab splits the back of its old shell and begins to ooze out slowly, its body weight assist the process as it drops downwards.If the crab is at the top of a pile of other crabs all high up on a structure, the old shell stays put and the soft shell crab falls down wards.