Fiddler crabs - good tank mates?

[LadyBloodraven]

Hello! I'm new to the forum here, decided to join after seeing so much awesome information in the threads. I've been raising freshwater fish since I was about 12 years old, and helping my dad beforehand. I do wind up with questions sometimes, but I also hope to be able to help other people with their questions too

All that aside, I have a 20 gallon long tank. Currently, it houses two red jewel cichlids and a convict. It had also a fiddler crab, but he just recently died due to a bad molt. (Poor guy.) I did tremendously enjoy the addition of fiddler crabs to my tank, they're awesome little guys. And yes, I did add salt to the water even though the stores like to label them as 'fresh water' when they are actually brackish. Houdini (the crab, as he kept disappearing.) would be harassed from time to time by the territorial cichlids, though they learned to let him be after a few snaps from that big claw of his! That aside, I know the harassment was stressful for him and probably added on to the cause of the bad molt. I'd rather this not happen again, and am planning on swapping my cichlids at my LFS for something else.

I was wondering what some good brackish tank mates would be for my future crabs? With it being a 20 long, I'm obviously concerned about space. I plan on getting a male fiddler and probably two females for company for him. With the size of the tank, they'll be pretty happy once I've built my crab ramps for them. I was figuring with the crabs liking to keep to their little hidey-holes and the bottom of the tank, a few mid and top level fish would be ideal, that won't grow too big, yet will be large and fast enough to not wind up dinner for the crabs. I was considering danios, but am not sure how they will do in brackish water. Any advice would be most definitely appreciated. Thank you for taking the time to read .

~Jade

 

[Alyxx]

Did you just add some freshwater salt or did you add marine salt and measure the salinity tone sure it was correct? Most freshwater fish will not be able to live in brackish waters, however, livebearers like mollies thrive in low end brackish water. Just be sure to give the crabs adequate room to walk around on land and they should do fine as long as the water is properly brackish.

 

[siva]

Hello and welcome to AA!

Danios can't go brackish. Mollies are much too large and create way too much waste for a partially full 20 gal, so I wouldn't go for those either. Bumblebee gobies are a good choice. They stay very small so you can definitely have a group of them with your crabs in a tank of this size. I keep them with my fiddlers and have never seen any issues between the two. They will both thrive at a salinity level of around 1.008. Make sure you are using marine salt for your brackish tank, and not aquarium salt, as this does not create brackish water.

Other inverts that can be acclimated to brackish are amano shrimp, ghost shrimp, malaysian trumpet snails, and nerite snails.