fiddler crabs

[fishing]

About a month ago, I purchased a five gallon tank and put a thin layer of gravel on the bottom. I then added about an inch high of brackish water at SG 1.010 to 1.012 to the tank. I decorated the tank with a few small stones and a plastic aquarium plant and added an airstone for some circulation. I let the tank sit for a few days and then I got eight fiddler crabs. Now I'm down to five. Three died within the last five days. I think some of them molted but I left the shedded shells in the tank for the crabs to consume. Why would they die like that? The crabs have access to dry land and they have brackish water. I thought that's what fiddlers like! By the way, I feed the crabs tetra bit pellets, water temp is 69 to 70 degrees and I leave the light on for nine hours a day. What could be wrong?

 

[Clown Monarch]

I don't buy crabs because the day after I put them in the tank, they're gone forever. Who knows if they're alive or dead or what, but I never see them again.

I'll never buy another crab of any kind.

 

[Veneer]

What was the salinity they were kept in prior to your purchase?

I don't buy crabs because the day after I put them in the tank, they're gone forever. Who knows if they're alive or dead or what, but I never see them again.

I'll never buy another crab of any kind.

I would strongly disagree with this generalizing sentiment, especially with regard to the larger true freshwater species (as "rainbow"/"moon"/"soapdish" crabs), which not only are continuously active in plain view (rooting about in gravel, shifting decor about the enclosure) but are also boldly patterned and highly interactive with the aquarist.

 

[TCTFish]

You have a new five gallon aquarium without any nitrifying bacteria established and you populated it with 8 inverts. Inverts make poor starters in a new tank and 8 of them is far too many too soon. The ammonia and/or nitrite may have gone up too fast for some of them to adjust.

I'd advise for you to test the water for ammonia, nitrite, nitrate, and pH. Please update me when you have the results.

In the mean time, it'd be good to do a 50% water change ASAP. Use a bio additive such as Nitromax, Cycle, BioZyme, BioSpira, etc. There are plenty to choose from.

What type of filter do you have for the tank?