Green Clown Goby

Gobiodon histrio

Also known as Broad-barred Goby, Green Coral Goby, Earspot Coral Goby

SaltwaterFish

Green Clown Goby (Gobiodon histrio) — Bjoertvedt · CC BY-SA 3.0

Care at a glance

Temperature: 72–79°F (22–26°C)
pH: 8.1–8.4
Adult size: 1.8 in (4.5 cm)
Minimum tank: 11 gal (40 L)
Temperament: Peaceful
Social behavior: Social
Swim level: Bottom
Difficulty: Easy
Breeding: Medium
Rarity: Very common
Reef safe: Reef safe with caution
Origin: Indo-West Pacific reefs, from the Red Sea to Samoa, north to southern Japan and south to the Great Barrier Reef
Family: Gobiidae

Overview

This is a peaceful, home-loving fish that spends its life around one coral head and rarely bothers other tankmates, though two unpaired individuals will squabble if forced to share a small tank. It rates reef safe with caution rather than a clean yes: it will not eat coral as food, but a pair defending its home coral can nip at the polyps and tips of SPS like Acropora, and egg laying on the underside of a branch can leave localized tissue damage. The risk stays low in a well stocked reef with several coral colonies to spread across, and it is close to a non issue in an LPS or soft coral tank with no SPS to perch on. Feed small meaty foods such as mysis and enriched brine shrimp a few times a day, since it does not travel far to find its own food.

In the wild

Lives on Indo-Pacific reefs where it perches directly on the branches of stony corals, especially Acropora, and rarely strays more than a body length from its host head. Pairs will often stay on the same coral colony for months, using its branches as both home and lookout post. In the aquarium it needs a mature reef tank with a branching coral or sturdy rock perch nearby and calm flow, not open swimming room or a sand bed.

Good to know

A small coral goby in the family Gobiidae, reaching about 4.5 cm, with a pale to olive green body marked by thin orange stripes on the head. It has no swim bladder and rests directly on its perch, propped on pelvic fins fused into a sucker-like disc. Its skin secretes a bitter, mildly toxic mucus that discourages predators, which is likely why such a small, slow fish can sit out in the open on a reef with little cover. Pairs are protogynous hermaphrodites and can change sex to match with a new partner.

Did you know

A green clown goby almost never leaves its home coral head. Moved elsewhere in the same tank, it will often work its way back across the rock to the exact branch it called home before.