Citron Goby (Gobiodon Citrinus) saltwater aquarium fish portrait

The Citron Goby is a compact, laterally compressed coral goby that reaches roughly three inches as an adult. Coloration is variable, ranging from bright lemon yellow and yellow-green through to dark brown or nearly black, and the species is identified by paired blue bars running through and behind the eyes, additional blue markings across the head, a blue stripe along the base of the dorsal fin, and a small dark spot above the pectoral-fin base. It occurs throughout the tropical Indo-West Pacific, from the Red Sea and the East African coast east to Samoa, north to southern Japan and south to the Great Barrier Reef. Like other members of its genus, it produces a toxic defensive mucus, which discourages many would-be predators.

In the wild this goby lives in intimate association with branching corals, and an aquarium should reproduce that structure. A reef-style layout with abundant branching architecture gives the fish perches, shelter, and defensible space. Mature, broadly branching Acropora colonies represent its natural home, but several branching coral skeletons make an effective substitute when live SPS is not part of the display. A single specimen is comfortable in a 30-gallon aquarium, while pairs or small groups do better in larger quarters offering multiple coral heads and separate territories. Water movement should allow the fish to perch securely and still receive food near its chosen branch.

Expect a largely stationary resident rather than an open-water swimmer. Much of the day is spent wedged among coral branches, with brief darting movements between perches. Stable tropical marine conditions and a well-established reef aquarium suit this species well, and its undemanding nature makes it a straightforward choice for aquarists who can provide the branching structure it depends on.

On the reef, the Citron Goby feeds on small invertebrates, zooplankton, and material taken from its coral host, including Acropora mucus and polyps. In captivity it takes small meaty items readily once settled. Mysis shrimp, enriched brine shrimp, finely chopped krill or prawn, and copepods all suit its small mouth, and prepared carnivore rations or small flakes are often accepted after a period of adjustment.

Feed small portions up to three times daily. Because this goby rarely leaves its perch to chase food, target-feeding near its coral is the most reliable approach when faster tankmates intercept meals. Freshly acquired specimens sometimes require live foods at first, then can be transitioned to nonliving items as they gain confidence.

Mysis Shrimp Enriched Brine Shrimp Copepods Chopped Krill Chopped Prawn Prepared Carnivore Foods Small Flake Foods
This is a peaceful, sedentary fish that spends most of its time perched inside a host coral. Wild observations record solitary individuals, mated pairs, and small groups. It will defend the coral it claims, and conspecifics may squabble in confined quarters, so keep one specimen unless a compatible pair has been established or the aquarium provides several widely separated coral territories. Suitable tankmates are small, docile species that feed calmly; large carnivores and boisterous, highly competitive feeders should be avoided.

Reef compatibility is generally good, with one caveat worth planning around. The goby may nip mucus or polyps from Acropora and other SPS corals, and a pair will sometimes clear a small patch of tissue from the underside of a branch as an egg site. Large, healthy, mature colonies typically absorb this localized wear, while small, sparse, or stressed colonies can suffer. Ornamental shrimp, crabs, snails, and clams are not at risk, and the species is harmless toward small fish.

FAQ

Frequently Asked Questions

About the Citron Goby

  • Does a Citron Goby need live Acropora?
    It naturally perches among branching Acropora, and mature colonies provide its preferred shelter. Where live SPS is not suitable, several branching coral skeletons offer secure substitute perches and hiding structure.
  • Will it damage SPS corals?
    It may nip Acropora mucus or polyps and can strip a small patch of tissue to prepare an egg site. Large, healthy colonies usually tolerate that localized damage, while small or limited SPS colonies warrant caution.
  • How do I get a reluctant newcomer feeding?
    Offer tiny portions of mysis, enriched brine shrimp, copepods, and chopped krill or prawn, target-fed near its perch up to three times daily. Live foods often help specimens that have not yet learned to take nonliving items.