Geosesarma sp. "Red" mottled coloration

[Swords]

Hello, I have had my group of 10 Geosesarma sp. "Red" (red carapace & black legs) for a few weeks now and I have noticed that one or more of the crabs have a brown mottled coloration on their legs and carapace while others are shiny black and bright red. Are the mottled individuals getting ready to molt?

[Ollie Mengedoht]

Hi Swords,

I wouldn't say so. Coloration is variable to some degree and dependent on the "mood" of the crab too. There are crabs that become paler before a molting (e.g. Cardisoma armatum) but we wouldn't know that from Geosesarma. Maybe they try to adapt to the substrat.

[Swords]

Someone on the Junglebox forum named Rangia linked to me a slideshow of your photos of the red Geosesarma on this page the crabs on the right side of the first photo:

http://www.panzerwelten.de/v/Geosesarma/...9.jpg.html

There are a number of them in that slide show who are exhibiting the same "brown mottling" I've seen on one or two of mine. Apparently this is OK and normal? Perhaps the brown mottled ones are juveniles or sub adults?

Why do your crabs cluster together in those photos? Mine all stay quite to themselves and usually only come out from their burrows to hunt one at a time. One will grab some food and disappear and then another will come out. Once I counted six but all in their own areas, not together as a group. When I got them people said they were communal and liked to hang out together like in your pics but mine do not exhibit this behavior.

[Ollie Mengedoht]

Hi Sowrds,

yes, if that is what You meant with mottling it is normal. Juveniles are the five pictures from 2010-05-28__DSC7536.jpg to 2010-05-28__DSC7544.jpg.

They cluster together because I made photos with them – obviously I can't use anything where every crab is hiding in a different place so I push them a little bit here and there so for some seconds they will sit together. They don't behave so in their tank or in natural environment, Youre's behave quite normally.