4 replies to this topic

[MattMudCrab]

Ok I think its best to ask about these here considering you guys are the brackish and saltwater peeps. I have a 40 gallon with over a dozen small thinstripe hermit crabs. They are all in dime size shells when we got them in July. Now most are over a quarter size. I know that these are considered by everyone on the googlenet to be horrible inverts that will eat everything yada yada. I do know when dealing with crustaceans as some exceed the size of others predation can occur. And these will get large. I expect to have 3-4 big crabs one day. Here is my questions. I currently have them on crushed coral should I add sand to give them something to burrow themselves in while molting? I know that land hermits will bury themselves for protection as the new exoskeleton hardens. These were collected in 1.012 specific gravity but they are commonly found in full marine. Will they need to be full marine eventually? Currently the only thing else in the tank is my Chasmodes boscquianus and a school of grass shrimp. No casualties yet.

[MattMudCrab]

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[Chasmodes]

Cool hermits.  I used to keep them years ago and they lived a long time, model tank citizens.  I used only dolomite gravel in those days, and that worked out just fine.  I kept three of them together.  Your sand/gravel combo should work OK.  I think that they just wedge themselves into a crevice or tank corner, then hide in their shell to molt.  I don't recall seeing mine try to burrow.

[MattMudCrab]

Thanks for the info. I went ahead and moved my Chasmodes, naked goby and clingfish in with them. It seems to be a good mix. Lot of grazing going on. All my rocks have a green cast but no visible algae beyond that. The grass shrimp graze the algae on the grass like herds of sideways cattle. Their activity level has reduced lately but I think its a combo of breeding season ended (lot of shell tapping was going on) and realizing the food is always coming.

[MattMudCrab]

Update, There was a bit of a scare because all at once the hermits just stopped. Several were not visible and the others stopped moving. The salt had been at 1.012 the I tested it and found it at 1.009. Research shows that they can tolerate down to 1.010. So I started increasing the salt level over a two week period to 1.017. They began to rise out of the substrate and go back to grazing. They still are not as active as originally but I think its due to the abundance of food and lack of competition. I also think they are active more at night now. The fish are doing well but they stay hidden more. My guess is an upgrade from a 20 high to a 40 long with no movement above makes them feel less secure. I am planning on adding some sheepshead minnows. Or something looking for a native marine addition once the salt level gets adjusted again. My guess is thinstriped hermits do eventually need full marine levels. I have had my water tested and everything is within range. And my Sea lettuce has exploded. Half of my tank has a green tint because the light has to shine through the macro algae.