Gobies
The largest family of marine fish, and most of them sit on the bottom. The pelvic fins are fused into a disc, which lets a goby hold station on rock.
Photo by krokodiver, CC BY 2.0
Overview
Gobies are the most diverse family of marine fishes, over 2,000 species and still counting, and most of them are tiny. The family holds some of the smallest vertebrates alive, and the ones cultured for aquariums run from roughly 25 to 75 mm.
They are also built to hold on. The pelvic fins are fused into a disc, which is what lets a goby grip coral, rock or aquarium glass in moving water instead of being swept off it. It is the reason a goby perches rather than swims.
Temperament
Alert, ground based and full of character for something that small. Gobies pick a spot, defend a small area around it, and watch everything from there.
Several kinds live in partnerships. Watchman gobies share a burrow with a pistol shrimp that does the digging while the goby watches for danger, and neon gobies work as cleaners, picking parasites off larger fish that queue for the service. Both arrangements are real behaviour rather than a curiosity, and both need the partner present to appear.
Care and grooming
Protein rich frozen and live food, in small portions and often. A goby will not chase food across a tank, so it has to arrive somewhere near the fish.
Marine species are kept at 25 to 28 degrees C, which is 77 to 82 F, at pH 8.0 to 8.3 and full strength salinity. Captive bred neon and watchman gobies are widely available, which is worth looking for: they are already used to prepared food and to a tank.
Living and exercise
Ten gallons upwards depending on the species, with rock work, small caves and a sand bed. The tank is furnished for perching and hiding rather than for swimming.
Gobies are ignored by most fish and ignore most fish in return. The exception is another goby of the same kind, since two of them will want the same rock. A lid is worth having, because a startled goby will leave a tank across the surface.
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