Green Clown Goby (Gobiodon histrio)

Also Known As: Green Coral Goby

Compatibility and Behavior
There's a lot of charm packed into the tiny Green Clown Goby (Gobiodon histrio). Under an inch and a half at most, it's a bright green little character accented with fine blue-to-turquoise lines and facial markings, with a compact, rounded body and oversized eyes that give it an almost toy-like look. It doesn't so much swim as perch and hop, resting on coral branches or rock ledges and making short darting movements between them, and that habit is a big part of its appeal in a nano tank where you can really watch it. Temperament is peaceful, and it does best in a calm community of other small, non-aggressive fish, ignoring larger inverts and other species entirely. Its natural home is nestled in branching SPS, which it uses for both shelter and spawning, and that's also the one caveat worth knowing: while plenty of hobbyists keep them in SPS systems without issue, a goby may occasionally irritate polyps or cause a little localized tissue recession where it perches or nests, so it's fair to call it reef safe with caution around delicate SPS colonies. It can also squabble with its own kind in very small tanks, so if keeping multiples, ensure you have enough space for them.

Aquarium Requirements
The small size makes this a natural nano fish, so a system around 10 to 20 gallons or more is a reasonable starting point for a single goby, with more room needed for a mixed community of Clown Gobies. What it really wants is structure to perch on, so branching live rock or coral gives it the ledges and nooks it lives on. Moderate, indirect flow is ideal, keeping water moving around its perches without knocking it off. Beyond stable water and mature rockwork, care is simple: offer a varied diet of small meaty foods like mysis, enriched brine, finely chopped seafood, and quality micro pellets to supplement whatever microfauna it picks off the rock and coral.

Specifications
Approximate Size: 0.75–1.5"
Diet: Carnivore; small meaty foods such as mysis, enriched brine, finely chopped seafood, and quality micro pellets
Origin: Indo-Pacific
Care Level: Easy to moderate
Reef Safe: With caution
Temperament: Peaceful
Minimum Tank Size: 10 gallons for a single specimen, with more space needed for mixed communities of Clown Gobies
Special Considerations: Reef safe with caution, as it may irritate SPS corals or cause localized tissue recession where it perches or nests; may be territorial toward its own kind in very small tanks unless kept as a compatible pair