Palauan Riffle Dwarf Goby

The Palaun Riffle Dwarf Goby, scientifically known as Stiphodon pelewensis, is a small, algae-grazing freshwater goby native to the island of Palau in Micronesia. Found in fast-flowing, crystal-clear mountain streams, this species thrives in oxygen-rich waters with rocky substrates and has become a unique and visually striking addition to specialized aquarium setups.

Physically, Stiphodon pelewensis is known for its vibrant coloration and delicate form. Males are especially eye-catching, often displaying intense iridescent blues, greens, and blacks along the body and fins, particularly when dominant or courting. Females are more subdued in appearance, with a light tan or grayish body marked by dark horizontal stripes. Adults typically reach about 1.5 to 2 inches (3.8 to 5 centimeters) in length.

In the aquarium, the Palaun Riffle Dwarf Goby thrives in a mature, well-oxygenated setup that mimics its native stream habitat. A tank of at least 15 to 20 gallons is recommended, with strong water flow, clean conditions, and a rocky substrate that encourages natural foraging. Smooth stones, boulders, and areas for biofilm accumulation are essential, as these fish spend most of their time grazing on surfaces.

Ideal water parameters include temperatures between 72 and 78°F (22 to 26°C), a pH of 6.5 to 7.5, and soft to moderately hard water. This species is sensitive to poor water quality, so regular maintenance and stable conditions are critical.

Feeding should focus on biofilm and algae-based offerings. While they will naturally graze on surfaces within the tank, supplemental foods like spirulina wafers, blanched vegetables (zucchini, spinach), and algae flakes can help support their diet. Over time, they may accept small frozen foods such as daphnia or brine shrimp, but high-protein items should be fed sparingly.

The Palaun Riffle Dwarf Goby is peaceful and does well with similarly sized, non-aggressive tankmates such as small rasboras, ricefish, hillstream loaches, or other gobies. Males may display territorial behavior, but this is usually mild when sufficient space and cover are provided.

Breeding in captivity is exceptionally rare due to their amphidromous life cycle. After spawning in freshwater, the larvae drift downstream to marine or brackish environments, returning to freshwater as juveniles—an environment difficult to replicate in home aquariums.

Overall, Stiphodon pelewensis (Palaun Riffle Dwarf Goby) is a beautiful and peaceful species best suited for aquarists interested in biotope-style or high-flow setups. Their unique appearance, algae-eating habits, and interesting behavior make them a rewarding challenge for experienced hobbyists.