Yellow Clown Goby (Gobiodon okinawae)

You must keep a single Yellow Clown Goby in tanks under 30 gallons (113 liters), or a bonded male-female pair in tanks of 20 gallons (75 liters) or larger. Gobiodon okinawae is aggressively territorial with conspecifics in confined spaces. Two unbonded individuals in a nano tank will fight over coral perches. In the wild, they live in groups of up to 15 individuals within a single large Acropora colony, but this requires massive reef systems with multiple coral territories. Because they are bi-directional hermaphrodites, any two individuals placed together will almost always form a bonded pair within a few weeks, with one changing sex as needed. Provide branching SPS corals such as Acropora or Pocillopora as perching structures. If no live coral is available, use faux coral branches or branching dry rock. Use a tight-fitting lid at all times; they are confirmed jumpers and can fit through surprisingly small openings.

Target pH 8.1 to 8.4, specific gravity 1.023 to 1.025 (32 to 35 ppt), Carbonate Hardness 8 to 12 dKH, General Hardness 7 to 12 dGH, Total Dissolved Solids 32,000 to 35,000 ppm, and temperature 72 to 82 degrees Fahrenheit (22 to 28 degrees Celsius). Ammonia and nitrite must remain at 0 ppm at all times. Maintain nitrates below 10 ppm with weekly 15 to 20% water changes. Use a protein skimmer rated for the tank volume and provide gentle to moderate water flow with calm areas near coral perches. Stable salinity is critical; fluctuations greater than 0.002 specific gravity in 24 hours cause osmotic stress. Always use a refractometer, not a hydrometer, for salinity measurement. Calcium 380 to 450 ppm and Magnesium 1,250 to 1,350 ppm are recommended to support SPS coral skeleton growth. Temperatures below 70 degrees Fahrenheit (21 degrees Celsius) suppress immune response and increase susceptibility to marine ich.

They are micro-carnivores requiring 55% protein, 15% fat, and 30% algae and plankton matter. Feed frozen cyclops, finely minced mysis shrimp, enriched brine shrimp, and small marine pellets sized 0.5 mm or smaller twice daily. They have extremely tiny mouths; food particle size must be under 0.5 mm. Target feed near their coral perch using a turkey baster or pipette. Wild-caught specimens may refuse prepared foods initially; offer frozen mysis or lobster eggs until they acclimate. Medication alert: Tolerate copper sulfate at 0.15 mg/L Cupramine but are sensitive to hyposalinity therapy. Praziquantel is safe for internal parasites such as Capillaria. Chloroquine phosphate at 15 mg/L for 14 days is the preferred quarantine prophylaxis. Avoid formalin dips. For external parasites, the Tank Transfer Method (TTM) is a non-chemical alternative. Because they are small and lack a heavy mucus coat, they are highly susceptible to marine ich; quarantine is mandatory. Metronidazole-soaked food treats intestinal flagellates and pinched belly syndrome.

Condition a bonded pair with enriched cyclops and baby brine shrimp for 3 weeks. Provide a branching SPS coral such as Acropora or a PVC T-fitting as a spawning substrate. The pair selects a coral branch; the female lays 200 to 1,000 adhesive eggs on the underside of the branch or on smooth rockwork. The male guards and fans the eggs for 4 to 7 days at 75 degrees Fahrenheit (24 degrees Celsius). Eggs hatch into pelagic larvae approximately 2 mm in length. You must catch the larvae immediately and move them to a pre-prepared 5 to 10 gallon raising tank with a sponge filter and water from the main tank. Larvae require rotifers enriched with phytoplankton for the first 7 to 10 days, then copepod nauplii, then newly hatched brine shrimp after 14 to 25 days. Metamorphosis begins at approximately 30 days of age when larvae start perching like adults. Switch to commercial microfoods at this point. Survival rates in home setups are low without dedicated larval-rearing equipment and continuous live food cultures. Happy pairs may spawn every 4 to 5 days. Captive-bred specimens are increasingly available from aquaculture facilities.