COBALT BLUE DWARF GOBY | STIPHODON SEMONI

The Cobalt Blue Dwarf Goby (Stiphodon semoni) is a small, peaceful, and brilliantly colored freshwater goby native to fast-flowing mountain streams across Southeast Asia and parts of Indonesia. Known for its dazzling electric-blue coloration and fascinating behavior, this species is a true gem for aquarists who appreciate vibrant nano fish and naturalistic river setups. Males display intense cobalt-blue to turquoise hues across their bodies, often highlighted by translucent fins and subtle golden or green undertones, while females are smaller and more subdued in color, typically brown or gray with faint spotting.

Adult Cobalt Blue Dwarf Gobies typically reach about 2 inches (5 cm) in length. They are active but gentle bottom-dwellers that graze continuously on algae and biofilm, making them both beautiful and functional members of a community aquarium.

Ideal water parameters:
Temperature: 72–80°F (22–27°C)
pH: 6.5–7.5
Hardness: 5–15 dGH

Tank setup:
Cobalt Blue Dwarf Gobies thrive in clean, well-oxygenated aquariums with moderate to strong water flow—mimicking their native stream habitats. A 20-gallon or larger tank is recommended, with smooth river rocks, driftwood, and sandy or fine gravel substrate. Encourage natural algae and biofilm growth, which they will graze on constantly. Good aeration and frequent water changes are essential, as they are sensitive to poor water quality. Dim to moderate lighting helps create a calm environment and promotes algae growth for natural feeding.

Diet:
These gobies are primarily algivores and micro-predators. In addition to biofilm, offer algae wafers, spirulina-based foods, and blanched vegetables such as zucchini or spinach. Supplement occasionally with live or frozen foods like baby brine shrimp or daphnia to ensure proper nutrition. Avoid high-protein diets meant for carnivores, as they can cause digestive issues.

Temperament and tankmates:
Cobalt Blue Dwarf Gobies are peaceful, curious, and compatible with other gentle species. Ideal tankmates include small rasboras, danios, ricefish, white cloud minnows, hillstream loaches, and shrimp. Avoid aggressive or large fish that may outcompete them for food or disturb them. Males may spar lightly over territory but rarely cause harm if space and hiding spots are available.

Breeding:
Breeding in home aquariums is rare, as their larvae require brackish or marine conditions to develop. However, males will often court females by displaying brighter colors and guarding small territories.

In summary, the Cobalt Blue Dwarf Goby (Stiphodon semoni) is a stunning, peaceful, and fascinating fish that brings a flash of electric blue and natural movement to freshwater aquariums. With proper care, oxygen-rich water, and a mature, algae-rich environment, these gobies thrive as one of the most visually striking and rewarding species for aquarists who enjoy serene, river-style setups.