Bumblebee Gobies And Fiddler Crabs

[Shred]

I've been offered a tank which I haven't actually seen yet, but from the current owners estimates I think its around 25-30 litres. I'd like to set it up in a similar fashion to the one in this thead. I would add a water pump to run through the sand and stone in the land part (under the sand, to keep it moist) into the water, and another outlet straight into the water to create some flow to help with the gobies eating. I would like 3 gobbies, probably 2 crabs. The land would be decorated with bogwood and slate for the crabs to climb on, and the water would be decorated with shells and perhaps some hardy plants such as anubias.

Does this seem like a plausable idea? Would the gobbies be ok with the crabs? And would the gobbies be ok living in a body of water which I'm guessing would be around 18 litres? (I have an idea for maximising the land and water mass, a sort of nail/mushroom shaped island, if you understand)

 

[nmonks]

The gobies should get along with small fiddlers just fine, since fiddlers mostly eat algae and organic detritus they extract from the sand. 30 litres/7 US gallons isn't much water space though, and while I've kept gobies in tanks around the 10 US gallon mark, if you're offering much less water than that, you may have problems. I'd approach this idea with caution, and would suggest skipping fish in favour of cherry shrimps and/or nerite snails, either of which will do fine in low-end brackish conditions. I really can't recommend keeping anything other than bettas in water volumes of 5 US gallons or less.

Cheers, Neale

 

[Shred]

Thanks for your reply Neale. I think I will have to just see how big the tank actually is and how much water mass I can keep in it along with the land. I'll keep you posted

 

[Shred]

I've just read in your brackish FAQ that there are a couple of marine hermit crabs that can live in brackish conditions, could that be an option for the water portion, or would they become fiddler food? Hermit crabs have always amazed me since I was little, but I've never been able to afford a marine setup so this is great news to me.

 

[nmonks]

There are various Clibanarius species that are found in brackish and even freshwater habitats. However, the tricky bit is identifying the species being sold! The blue-legged hermit crab Clibanarius tricolor seems to be quite widely sold and appears to do well in high-salinity brackish water systems, from about SG 1.010 at 25 degrees C upwards. Clibanarius vittatus is, if anything, even better suited to mid to high salinity brackish water conditions.

The problem is of course identifying the hermit crab being sold. It's a good idea to go by the Latin name rather than the trade name. Adapt your hermit carefully using the drip method so that it "feels" as if it's been exposed to a tidal change in salinity, which would take several hours in the wild. Observe carefully to make sure the hermit is happy, and remember that even though you're maintaining it at a reduce salinity, things like water quality will still need to be comparable to a marine aquarium. In other words, you want a high pH, lots of carbonate hardness, quite possibly a skimmer, and you will need to take very great care to avoid exposure to copper.

Cheers, Neale

I've just read in your brackish FAQ that there are a couple of marine hermit crabs that can live in brackish conditions, could that be an option for the water portion, or would they become fiddler food? Hermit crabs have always amazed me since I was little, but I've never been able to afford a marine setup so this is great news to me.

 

[Shred]

Thank you very much for the info. Not sure if I'd be able to get a skimmer in that little tank but I might be able to knock something up...

Any idea about compatabilities with the fiddler crabs? I pressume they would be ok due to what you said about the fiddlers diet.

 

[nmonks]

Fiddlers require much the same thing as terrestrial hermit crabs, and spend almost no time underwater given the chance. They can't be kept in normal aquaria. They need a habitat with an inch or two of brackish water, a big sand bank on which they can feed, and a tangle of bogwood roots and plastic plants they can clamber around and use for displaying.

They don't mix especially well with other animals, though mudskippers and gobies can work, provided the fish aren't so big they will damage or eat the crabs (some of the larger mudskippers eat fiddler crabs in the wild, and will happily do so in captivity). Endler guppies and bumblebee gobies would make good choices, but this does rather assume the the watery side of the vivarium contains at least, say, 25 litres/8 gallons of water.

Cheers, Neale

 

[Shred]

Ok thanks I'll stick to amano shrimp for the fiddler tank then. I'll save the hermits for a future project.

 

[reeeedfish]

Don't forget to post pics.