Earspot Coral Goby Care Guide
Gobiodon atrangulatus is a tiny Western Pacific coral goby that lives among Acropora corals in an obligate, monogamous social system.
Compiled by Aquairi from published sources · Published · Updated
Overview
Gobiodon atrangulatus, the Earspot Coral Goby, is a very small marine coral goby of the Western Pacific. FishBase classifies it as a coral-commensal species found among Acropora corals, with an obligate and social monogamous mating system. Like its relatives in the genus it is capable of facultative air-breathing.
Taxonomy
- Family: Gobiidae
- Genus: Gobiodon
- Scientific name: Gobiodon atrangulatus
Habitat
FishBase records the species in the Western Pacific between Japan and Fiji. It is a non-migratory tropical reef fish found among the branches of Acropora corals.
Tank requirements
- Minimum tank volume: 50 L
- Temperature: 24-26 °C (75-79 °F)
- pH: 8.1-8.4
- Specific gravity: 1.024-1.026
- Carbonate hardness: 8-12 dKH
- Maximum size: about 3.5 cm
- Lifespan: 3-6 years
Diet
A carnivore. In the aquarium it accepts small meaty foods such as cyclops, enriched brine shrimp and finely chopped mysis, fed twice daily.
Compatibility
A peaceful species that forms monogamous pairs. It suits calm companions such as clownfish, cardinalfish and wrasses; lionfish and other predators should be avoided.
Reef compatibility
Reef-safe with the caveat that it perches on branching Acropora and may occasionally nip at small-polyp stony coral polyps. It is otherwise harmless to the reef and depends on branching corals for shelter.
Breeding Gobiodon atrangulatus (Earspot Coral Goby)
Overview
Gobiodon atrangulatus Garman, 1903 is a small coral goby of the family Gobiidae, recorded from the Western Pacific around Japan and Fiji. FishBase reports a maximum size of 3.5 cm TL and notes that the species is found among Acropora corals, where it lives commensally on the branching colony. Captive spawning is documented at genus level rather than for this species specifically, so the guidance below combines its confirmed monogamy with breeding patterns established across Gobiodon.
Sexing
Coral gobies of the genus Gobiodon are difficult to sex visually, and several species are bidirectional (serial) sex changers. Published work on Gobiodon shows that immature individuals are typically female and that sex change occurs in whichever direction favours forming a breeding pair, so two same-sex fish placed together can resolve into a male and a female. A pair is therefore established by housing two compatible individuals rather than by selecting a confirmed male and female.
Conditioning
FishBase records monogamous mating in Gobiodon atrangulatus as both obligate and social, meaning a settled pair stays bonded to a host colony. Conditioning centres on a stable reef system with a healthy branching Acropora (or comparable structure) for shelter and a spawning surface, plus frequent small carnivorous feeds matching the species' trophic level of about 3.2.
Breeding Setup
A nano to small reef system that supports stable parameters is appropriate, with one host coral colony per pair to avoid territorial conflict. Reef-typical conditions reported for the species in the knowledge base are temperature 24-26 degrees C, pH 8.1-8.4 and moderate flow. Because the genus is obligately monogamous, only a single pair should occupy each colony.
Spawning Behavior & Trigger
Across Gobiodon, the size-matched pair deposits demersal (attached) eggs on the surface of the host coral branch, and the male tends the clutch. Spawning is tied to the security of an established pair on a healthy colony rather than to a documented external trigger in this species, so a stable, well-fed pair is the main prerequisite.
Egg & Fry Care
The male guards and aerates the eggs on the coral branch until hatching. Larvae are pelagic on release and receive no further parental care. A practical protocol for rearing Gobiodon atrangulatus larvae has not been published, and survival through the planktonic stage is the principal obstacle to captive production.
Common Challenges
- Securing a bonded pair, since the fish are obligately monogamous and aggressive toward extra conspecifics on the same colony.
- Providing and maintaining a living branching coral host without it being harmed by aquarium stressors.
- Rearing the planktonic larvae, for which no validated diet or settlement protocol exists for this species.