Description
Two Spot Goby (Signigobius biocellatus)
Overview
The Two Spot Goby (Signigobius biocellatus), often called the Twinspot Goby or Crab-eye Goby, is a uniquely patterned and fascinating bottom-dwelling fish. It is widely regarded as one of the most beautiful gobies, known for its intricate camouflage and interesting sand-sifting behavior.
- Appearance: Features a tan-to-gray body covered in reddish-brown spots and two prominent “eyespots” on the dorsal fins, which help deter predators by making the fish appear larger or like it is looking in two directions.
- Size: Small and manageable, reaching about 7–8 cm in length.
- Behavior: A dedicated “sifter.” It spends its day taking mouthfuls of sand, filtering out small organisms and detritus, and expelling the clean sand through its gills.
- Lifespan: Generally 2–4 years in captivity, as they can be difficult to keep fed long-term.
Care Requirements
- Tank Size: A minimum of 30 gallons is recommended. They require a significant footprint of fine sand substrate (not coarse coral rubble, which can damage their gills during sifting).
- Aquascaping: Needs an established tank with a deep, mature sand bed rich in microfauna. They are shy and require plenty of live rock for cover.
- Water Parameters:
- Temperature: 74–80°F (23–27°C).
- Salinity: 1.020–1.025 SG.
- pH: 8.1–8.4.
Maintenance
Avoid aggressive sand-sifting tank mates (like larger gobies or wrasses) that will outcompete them for food.
Diet
- The Feeding Challenge: This is the primary reason this species is considered expert-only. They are specialized feeders that rely heavily on the microfauna (copepods, amphipods, etc.) living within your sand bed.
- Captive Feeding: It is often difficult to transition them to prepared foods. You may have success with high-quality frozen foods like cyclops, enriched brine shrimp, or mysis, but they should ideally be kept in a tank that has a “refugium” providing a constant supply of live micro-crustaceans.
Behavior and Compatibility
- Temperament: Extremely peaceful and shy. They are non-aggressive toward other fish but can easily be bullied by more active species.
- Compatibility: Best kept in pairs (they often form stable monogamous pairs) or with very slow-moving, peaceful tank mates like small blennies or dragonets.
- Reef Safety: Completely reef-safe. They will not bother corals, invertebrates, or small crustaceans.
Reproduction
Two Spot or Crab-eye Goby, is widely considered very difficult to breed in home aquarium conditions, and there are currently no reliable or consistent reports of successful captive reproduction by hobbyists.
Tips
- Establishment: Do not add this fish to a brand-new, sterile aquarium. The tank should be established for at least 6+ months with a healthy, “living” sand bed.
- The “Spot” Defense: The eyespots on their dorsal fins are not just for show; if they feel threatened, they will raise their fins to intimidate perceived predators.
- Avoid Over-Cleaning: If you vacuum your sand bed too thoroughly, you will remove the food source this goby needs to survive.
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.
