Description
Yellow Watchman Goby (Cryptocentrus cinctus)
Overview
The Yellow Watchman Goby (Cryptocentrus cinctus) is a favorite in the marine aquarium hobby, valued for its striking yellow coloration, fascinating symbiotic relationship with pistol shrimp, and generally hardy nature.
- Temperament: Peaceful (can be territorial toward other gobies)
- Reef Safe: Yes
- Max Size: Approximately 8 cm
- Origin: Western Pacific
Care Requirements
- Tank Size: A minimum of 80–90 litres is recommended. They are not highly active swimmers and prefer to remain close to their burrow.
- The Symbiotic Duo: While they can be kept alone, they are best kept with a Randall’s Pistol Shrimp (Alpheus randalli). The shrimp digs a burrow that the goby guards; in exchange, the shrimp—which has poor eyesight—is warned of danger by the goby’s keen vision.
- Substrate: A deep sand bed with a mix of coarse sand and small rubble is essential, as the shrimp needs material to construct and maintain their shared burrow.
- Lid: Like all gobies, they are jumpers if startled. A tight-fitting lid is required.
- Water Parameters:
- Temperature: 22–27°C
- Salinity: 1.023–1.025
- pH: 8.1–8.4
Maintenance
- Substrate Integrity: The most important aspect of their maintenance is ensuring the sand bed remains undisturbed. Do not use gravel vacuums in the immediate area of their burrow. If you have a pistol shrimp pair, the shrimp will manage the entrance to the burrow; avoid cleaning near this entrance to prevent the tunnel system from collapsing.
- Feeding Hygiene: Because they are not aggressive feeders, they may miss out on food if other fish in the tank are fast or aggressive. Perform “target feeding” using a long pipette or turkey baster to ensure the goby (and its shrimp partner, if present) receives enough food directly near their burrow entrance.
- Lid Maintenance: Regularly inspect your tank lid or mesh cover. Because these gobies are prone to jumping when startled, even a small gap can be fatal if the goby becomes spooked by a more aggressive tank mate or sudden light changes.
- Behavioral Cues: A healthy Yellow Watchman Goby will spend much of its day “perched” at the entrance of its burrow. If it stays hidden for extended periods (beyond the normal adjustment phase) or appears pale, check your water parameters for hidden spikes or observe the tank for signs of bullying from other bottom-dwelling fish.
- Compatibility Monitoring: If you add new tank mates, observe their interaction with the goby’s burrow area. While peaceful, they are territorial about their immediate living space and may nip at other gobies or blennies that attempt to enter their den.
Diet
- Feeding Frequency: Feed 2–3 times daily.
- Foods: They are carnivores and appreciate meaty, protein-rich foods:
- Frozen mysis shrimp, enriched brine shrimp, and finely chopped seafood.
- High-quality small marine pellets.
- Feeding Tip: Since they are not aggressive feeders and often stay near their burrow, ensure food reaches them directly or drifts near their home.
Behavior and Compatibility
- Social Behavior: They are generally peaceful but will defend their burrow against other bottom-dwelling fish, particularly other goby species.
- Compatibility: Excellent for community reef tanks with other peaceful, mid-water swimming fish (such as small wrasses, firefish, or clownfish). Avoid keeping them with overly aggressive or predatory fish that might harass them.
Reproduction
They are known to spawn in captivity in well-established reef systems. The male guards the eggs, which are typically laid inside the burrow. While breeding is possible, raising the larvae is notoriously difficult and requires specialized equipment and rotifer cultures.
Tips
- Patience: If you add a pistol shrimp to your tank, don’t be alarmed if you don’t see them for a few days. They are shy and need time to excavate their tunnel system.
- Watch the Burrow: A happy Yellow Watchman Goby will spend much of its time perched at the entrance of its burrow, watching the tank. If you see the goby and shrimp together, you are seeing one of the most interesting behaviors in the hobby.
- Acclimation: Take care when adding them to the tank. They can be sensitive to environmental shifts; a slow drip acclimation is recommended.
Picture for illustrative purposes only. Either come in store to view available stock or request pictures to be sent to you.
Please Note: Due to variations within species resulting from age, region, sex, etc., the actual livestock may not look identical to the image. Approximate size range may also vary between individual specimens.
