Bumblebee gobies are not particular to brackish water in the wild and they don't migrate into brackish water.
Some gobies (e.g.,
Awaous spp.) do migrate. Candy stripe gobies (
Awaous flavus) live in fresh and lay eggs in fresh, but the fry migrate downstream to the sea and need at least strongly brackish, perhaps marine, conditions. See the report by a goby scientist, Naomi Delventhal, here:
http
/gobiidae.com/breeding_awaous.htm
A useful summary of bumblebee goby maintenance and breeding is provided by Naomi Delventhal at the
Yahoo Goby Group.
Finally, in the recent Aqualog book, Frank Schaefer, a fish collector, makes it very clear that these gobies are found in fresh, not brackish, water.
Having said that, adding salt probably does help in soft to neutral water conditions. It may also help with fish that are sick or stressed, either as a tonic or as a way of treating external parasites. They also seem easier to breed in brackish, though this may be more about fungal infections of the eggs than anything else. So there are good reasons to keep bumblebees in brackish, they just aren't the reasons people usually quote.
It may also depend on where they are collected. Ones collected from brackish water may well do best kept in brackish water. But there are lots of people keeping and breeding them in fresh water. On the other hand, if you want to keep them in (very slightly) brackish, with, for example, some glassfish or wrestling halfbeaks, that would work well.
Bumblebees
do not accept flake food. You will need to provide them with frozen foods, e.g., lobster eggs or bloodworms, and make sure other fish leave enough for the gobies. They are otherwise easy to care for. They should survive at least a couple of years in captivity (my understanding is the maximum lifespan is around 4 years!).
Cheers,
Neale
PS. Naomi Delventhal was kind enough to help me fill out the bumblebee section of the Brackish FAQ (see link below). She keeps and breeds these fish regularly, as well as other gobies.
