西豪氏枝牙鰕虎鱼 · Cobalt Blue Goby

Overview

A vivid blue side stripe and rounded, nearly transparent dorsal fins are useful clues to male Stiphodon semoni. Trade names overlap with those of other blue gobies, so a label does not establish identity. Care requires an established stream aquarium with abundant grazing surfaces.

Distribution & habitat

The known range stretches from western Sumatra across Indonesia and northern New Guinea, through the Bismarck Archipelago, to the Solomon Islands. Typical habitats are higher stream sections, often beyond waterfalls, where narrow fast runs alternate with broader slow stretches. Clear oxygenated water and light sustain biofilm over bedrock and scattered stones.

Aquarium setup

Combine sand or gravel with rounded rocks. Set heavy stones firmly on the base before adding substrate because males dig during rest and spawning. Multiple males need retreats and visual separation. Strong light supports algae, while seasoned wood or attached plants can add cover. Avoid fresh wood that heavily darkens the water.

Maintain clean conditions using filtration, circulation, and aeration. Suggested hourly turnover is about 10–15 aquarium volumes, with 5–10 feasible under good oxygenation. Replace roughly 30–50% of the water weekly and agitate the surface more in warm conditions. Preserve useful grazing films. Secure the lid and openings against glass-climbing fish.

Diet & feeding

Feeding guidance for the genus centers on algae and their associated microorganisms. Accepted sinking products or small portions of bloodworms are occasional supplements. Stones grown with algae in a separate bright container can replenish grazing surfaces; tough black brush algae is not a reliable food reserve. Thin fish need easy access to suitable food without strong competition.

Behaviour & compatibility

Peaceful, similarly sized open-water fishes with matching environmental needs can be suitable. Exclude forceful feeders, large fishes, and territorial bottom-dwelling cichlids. Males show some territoriality, but several can coexist with enough space, cover, and food. Females associate more loosely; one male with at least two females is a suggested group.

Sexual dimorphism

Males have a gray background and a blue-green stripe that may become almost white during dominance or courtship. Females are paler with a dark irregular lateral stripe.

Breeding

The genus reproduces in freshwater streams, followed by marine larval development and a return upstream. Observations of spawning and male guarding do not establish a routine freshwater rearing procedure. The marine stage is the central difficulty, and larval schedules from related species are not automatically applicable.

Notes

Compared with the similar Stiphodon atropurpureus, this fish has rounder, much clearer dorsal fins rather than dusky ones. Some males show an additional gold band above the blue stripe for reasons that remain uncertain. Locality and structural details help resolve mislabeled fish and photographs.