TankBud

Citron clown goby

Gobiodon citrinus

Also known as Citron Goby, Citrinis Goby, Poison Goby

SaltwaterFish

Citron clown goby (Gobiodon citrinus)
Rob · CC BY 2.0

Care at a glance

Temperature
72–81°F
22–27°C
pH
8.1–8.4
Adult size
2.6 in
6.5 cm
Minimum tank
11 gal
40 L
Temperament
Peaceful
Social behavior
Social
Swim level
Bottom
Diet
Carnivore
Difficulty
Easy
Breeding
Medium
Rarity
Common
Reef safe
Reef safe with caution
Family
Gobiidae
Origin
Indo-West Pacific reefs, from the Red Sea and Mozambique to Samoa, north to southern Japan and south to the Great Barrier Reef

Overview

The citron clown goby is a small, bright yellow goby for a mature reef tank. It is easy to keep and peaceful with other fish, though it may nip the coral it calls home.

Did you know

The citron clown goby's bright yellow color and toxic mucus coating work well as a deterrent to predators. It often sits fully exposed on top of a coral head in broad daylight. For most fish this size, that spot would be a death sentence.

Caring for the citron clown goby

Give citron clown gobies a mature reef aquarium of at least 11 gal (40 L). Each needs a coral head or sturdy branching rock to call home, not open water or sand. Keep the water at 72 to 81°F (22 to 27°C), with a pH of 8.1 to 8.4.

Citron clown gobies rate reef safe with caution, with little to no risk in LPS or soft coral tanks. They are known to nip at the flesh and polyps of a host Acropora. That will not kill a large, healthy colony, but it can seriously set back a small frag. Give them a few coral heads or one large colony to work over, so any nipping stays spread out and minor.

Feed small meaty foods such as mysis shrimp, enriched brine shrimp and frozen carnivore preparations. Offer them close to the perch, since these gobies do not forage widely.

Citron clown gobies are peaceful toward other fish and make an easy, undemanding community member. Two unrelated fish in one tank will often fight until one asserts dominance or they pair off. Breeding them is moderately difficult.

Good to know

The citron clown goby is a member of the family Gobiidae. It is bright lemon yellow overall, with a pair of thin blue lines running from the snout through the eye. Like its relatives, it lacks a swim bladder and rests propped on fused pelvic fins. Its other name, poison goby, comes from the bitter, toxic skin mucus that protects most Gobiodon species from predators. It is a protogynous hermaphrodite, and a paired fish can switch sex if its partner is lost.

In the wild

The citron clown goby is native to Indo-West Pacific reefs, from the Red Sea and Mozambique east to Samoa. Its range runs from southern Japan south to the Great Barrier Reef, usually at depths of 2 to 20 meters. Like other clown gobies, it spends its adult life perched on a single coral colony and rarely swims far from it. It typically lives among the branches of Acropora or similar stony corals.

Symbiotic relationships

Clown gobies and their Acropora

Clown gobies spend their lives wedged in the branches of Acropora corals, eating the coral's mucus and the small animals that live on it. Their skin carries a toxin that puts off predators, so the coral becomes a safe house. The coral is paid back in a way nobody expected: when a toxic seaweed touches an Acropora, the coral releases a chemical signal within minutes, and the gobies swim out and trim the seaweed back. Corals with gobies lose far less tissue to seaweed than corals without them.

A clown goby wants a branching coral to sit in, and Acropora is the natural choice, though it will settle for other branching stony corals. It is tiny, peaceful and needs small food several times a day. The one caution is the coral itself: a pair may nip a patch of Acropora or Montipora bare to lay eggs on the skeleton, and a small colony can lose a branch that way. Keep one, or a pair, per tank; two males fight.

Every symbiotic relationship in the catalog

Weekly picks

Tank mates

The citron clown goby is a peaceful, social species that keeps to the bottom. These picks share a community profile with it, are safe together in both directions, and overlap on water type, temperature and pH.

Check the full mix in the stocking calculator

Common questions

What size tank does a citron clown goby need?

A citron clown goby needs at least 11 gal (40 L). It spends most of its time in the bottom.

What temperature and pH does a citron clown goby need?

A citron clown goby is comfortable at 72–81°F (22–27°C) with a pH of 8.1–8.4.

What does a citron clown goby eat?

A citron clown goby eats small meaty foods such as mysis shrimp, enriched brine shrimp and frozen carnivore preparations. Feed it close to its perch, since it does not forage widely.

How big does a citron clown goby get?

An adult citron clown goby reaches about 2.6 in (6.5 cm).

Related species