Citron Goby
Gobiodon citrinus
The Citron Goby, also known as the Blue-streaked Acropora Goby, is a wonderfully distinctive little marine fish. Its beautiful yellow body is decorated with fine, electric-blue lines around the eyes and gill covers, together with a delicate blue stripe running along the base of its dorsal fin.
Unlike active open-water swimmers, the Citron Goby prefers to spend much of its day perched on rockwork or nestled among branching corals. From these sheltered positions, it carefully observes its surroundings before making short, quick movements to capture passing food.
Native to coral reefs throughout the Indo-Pacific, this species has a particularly close relationship with branching Acropora corals. These structures provide shelter, protection and familiar resting places, allowing the goby to move confidently through its chosen territory.
One fascinating characteristic of the Citron Goby is its protective skin mucus, which contains substances that help discourage potential predators. Combined with its preference for narrow coral branches, this gives the fish an unusual approach to life on the reef.
Although generally peaceful towards unrelated fish, the Citron Goby can be territorial towards other coral gobies, particularly when defending a favourite shelter.
Its relationship with Acropora also requires careful consideration. While commonly maintained in reef aquariums, Citron Gobies may nip coral polyps or clear small areas of living coral tissue when preparing to reproduce.
With its remarkable markings, curious behaviour and tendency to observe the aquarium from favourite perches, the Citron Goby offers plenty of personality in a small package. It is particularly well suited to mature, peaceful marine aquariums with intricate rockwork and suitable sheltered resting places.
Feeding Notes
Citron Gobies are small, coral-associated carnivores that feed on zooplankton, tiny crustaceans and other small invertebrates. They may also consume coral tissue in their natural habitat, particularly from the Acropora colonies they inhabit.
In the aquarium, offer a varied diet of frozen mysis, enriched brine shrimp, copepods, finely chopped marine seafood and suitable small marine carnivore pellets.
Feed small portions twice daily, choosing foods appropriate to the fish's mouth size.
Citron Gobies are predominantly perch-and-wait feeders. They often remain on a favourite rock or coral branch, making short movements to capture passing food rather than swimming actively through the aquarium.
Ensure that the fish receives sufficient food. Fast, assertive tankmates may consume available food before the goby has an opportunity to feed. Target feeding or offering food close to its preferred perch can be helpful.
Some newly introduced specimens may initially refuse prepared foods. Appropriately sized live or frozen foods may help establish a reliable feeding response.
Important: Citron Gobies may naturally consume Acropora tissue. Providing an appropriate prepared diet does not guarantee that an individual will stop nipping coral polyps.
Aquarium Setup Notes
Provide a mature, stable marine aquarium of at least 80 litres, preferably with a minimum tank length of 60 cm, established rockwork and numerous sheltered perching areas.
In the wild, Citron Gobies live among the branches of Acropora corals, using the intricate structure for shelter, protection and access to food.
An aquarium containing mature branching corals can provide opportunities to observe this natural behaviour. However, live Acropora is not essential for keeping a Citron Goby successfully, provided suitable complex rockwork or coral-like structures offer secure shelter.
Arrange the aquascape with multiple small ledges, narrow openings and protected resting areas. These fish spend considerable time perched rather than swimming continuously in open water.
Provide moderate overall circulation with gentler areas around the fish's preferred shelter. Strong, direct flow should not continually dislodge the goby from its resting position.
Maintain stable reef water parameters, reliable biological filtration and good oxygenation. Lighting can follow the needs of the aquarium's other inhabitants; the fish itself does not require specialised lighting.
No deep sandbed is required. Unlike sand-sifting gobies, the Citron Goby spends most of its time among rockwork and coral structures.
Use a secure aquarium cover. Although this species is not a particularly active open-water swimmer, it is capable of jumping when startled or chased.
Pay attention to overflow openings and pump intakes, particularly when housing very small specimens.
Compatibility Notes
Citron Gobies are generally peaceful towards unrelated marine fish and are best maintained with small, non-aggressive tankmates.
Suitable companions may include peaceful clownfish, cardinalfish, small blennies, firefish and other calm marine species that do not prevent the goby from feeding or accessing shelter.
Avoid aggressive damselfish, territorial dottybacks, large predatory wrasses, hawkfish and other fish capable of intimidating or consuming small gobies.
Best kept singly or as an established compatible pair. Wild Citron Gobies may occur individually or in pairs, but unrelated individuals can become territorial towards one another, particularly in smaller aquariums or where suitable shelters are limited.
Reef safe with caution: This species is closely associated with branching Acropora corals but may feed on their polyps or tissue.
When preparing a spawning site, a compatible pair may clear a small area of coral tissue from a branch to deposit eggs.
This behaviour can be particularly damaging to small Acropora fragments or delicate colonies where even limited tissue loss is significant.
In larger, established coral colonies, the interaction may be better tolerated, but compatibility cannot be guaranteed.
Citron Gobies are not generally considered major predators of ornamental marine shrimp, snails or other larger reef invertebrates, although they naturally consume tiny crustaceans and other small organisms.
Their protective skin mucus helps discourage predators but does not make them immune to attacks from larger fish.
For long-term success, provide peaceful tankmates, regular small feedings, extensive sheltered perches and careful monitoring of any Acropora corals within the aquarium.