Uca Pugnax

[Imperata]

I hope I am putting this in the right section! I have a fiddler crab whos gone thru a molt and is HUGE probably 3 inches across the shell not including legs. His claw is about 4 inches across. I have been keeping him in my 55 gallon community tank with marine salt added for 3 weeks out of a month with one week in a dry ten gallon with a water dish.

Apparently this is the formula for a VERY healthy crab! I feed Hbh crab and lobster bites plus whatever he eats off the bottom of the tank. I was wondering if anybody has any experience with these guys?

 

[Imperata]

I would love any advice or more info on how big these guys can get because everything I have seen has said 2 and half inches is top-out in size. Well obviously they can get bigger. Any info would be great!



And hey on a sidenote I am keeping my mbunas in a brack enviroment and they are tolerating it and seem to be thriving. As in growing fast and consuming massive quantities of food. They eat a head of broccoli a week.

 

[nmonks]

Most Uca species stay quite small, shell widths up to 2.5 cm/1 inch being typical. I have never seen an Uca species with a shell width of three inches, so I do wonder if you're identifying your crab correctly and/or measuring it accurately. Most sources give the maximum shell width for Uca species at around 5 cm/2 inches.

In any case, their basic care in captivity isn't too difficult. They're brackish water scavengers, and most species will eat any organic matter made available to them. Salinity isn't a crucial factor, but SG 1.005 is about right for the average store-bought fiddler. In the wild activity is based around hiding in burrows when the tide is in, and then scampering about on land feeding and socialising when the tide is out. Under aquarium conditions they are more or less terrestrial, and do best in tanks with shallow water (a few inches is adequate) around a big mound of coral sand shored up with bogwood and stones. They are burrowers by nature, so it's a good attempt to provide various small shelters if they can't dig their own.

I've come across several reports of generic "mixed African" mbuna cichlids in brackish water. Yours are presumably Pseudotropheus zebra-based hybrids, and yes, these can tolerate slightly brackish water. However, there does seem to be a connection between salt and Malawi Bloat, so keeping Rift Valley cichlids this way is not something I recommend.

Cheers, Neale

 

[Imperata]

Thanks Neale for replying! I am measuring from one end to the other right behind the eyes across the shell only. I bought him from a tank full of them and he was the smallest one in there. He has been this size thru 2 molts. Can I assume that that means he has quit growing? I wish I could show a photo but my photobucket account will not let me link pics here.


And you are right I mostly have zebra crosses. I have one king ice blue who is about 8 inches long. I got them from a neighbor who had them in a ten gallon with an oscar . The reason I used marine salt and brought my salinity up to medium brack was because they were COVERED in these hairy wormy things that would rip bleeding gouges out of them. They were skeletons when I first got them. The brack enviroment is apparently not friendly to those parasitic worms cuz they have all died.