Bumblebee Gobies (Brachygobius Species)
Bumblebee gobies (Brachygobius sp.) are interesting, small fish from the family Gobiidae. They are one of the few gobies that can be kept in freshwater tanks, although they are actually brackish water fish, and really need to be kept in brackish water conditions.
Bumblebee gobies originate from Southeastern Asia and are found in shallow coastal waters and estuaries, which are places where freshwater rivers and streams flow into the ocean, mixing with the seawater. This means that their water requirements are going to be somewhere in between freshwater and saltwater (in other words, brackish water conditions).
To create brackish water conditions it is much better to use sea salt (such as Instant Ocean) and not freshwater aquarium salt. Sea salt mixes contain all of the necessary elements for the health of your fish, whereas freshwater aquarium salt contains only sodium chloride.
You should always use a hydrometer so that you can accurately measure your tank's salinity. You don't want a tank that is too saline or one that isn't saline enough. Hydrometers are inexpensive and can be found at most pet stores that sell aquarium supplies.
A hydrometer measures salinity indirectly through specific gravity. Specific gravity is the ratio of the density of a given solid or liquid substance to the density of water at a specific temperature and pressure.
The specific gravity for bumblebee gobies should be approximately 1.005-1.008. For your reference, the specific gravity of distilled water is 1.000 and seawater is 1.023.
If your bumblebee gobies are used to being in freshwater (such as at the pet store where you purchased them), I recommend making the change to brackish water gradually.
The name "bumblebee gobies" is derived from their bold black and yellow stripes. They are small fish that typically reach an adult size of less than 2 inches (<5 cm) in length.
They usually inhabit the bottom layer of the tank. Bumblebee gobies can be quite shy unless they are kept in a species only tank. They can be kept with other species, however, you will see much more of your gobies if they are kept in a species only tank. If you do decide to keep other fish species in your bumblebee goby tank, keep in mind that they also need to be brackish water fish.
The bumblebee goby tank should contain lots of rocks and caves for hiding places, as well as some plants. Their water temperature should be between 74-80 °F (23-27°C).
Feeding Bumblebee Gobies
Bumblebee gobies are carnivores, but are often reluctant to eat flake or dried foods. They will often eat frozen meaty foods (such as brine shrimp) and live foods.
If you'd like to see a video on feeding a bumblebee goby then watch the following You Tube video:
If possible, try to vary the live and frozen foods for your gobies, instead of feeding them the same food each day.
Bumblebee Gobies Breeding
Male and female bumblebee gobies look similar to one another, although the female may be more robust when she is in breeding condition.
During spawning, the eggs will be laid on rocks. The eggs will be guarded by the male and the female should be removed at this time.
To help induce spawning behavior you can decrease the salinity a little by adding freshwater. In their natural habitat they spawn during the rainy season.
The eggs will hatch in about two days. Feed the goby fry infusoria when they are free swimming and after a few days start them on baby brine shrimp.