深黑枝牙鰕虎鱼

Overview

Male Stiphodon atratus becomes strikingly dark, with larger individuals showing a solid black region between the second dorsal and anal fins. Successful care depends on established grazing surfaces and oxygenated water. A powerful current by itself cannot replace a mature aquarium with enough suitable food.

Distribution & habitat

Its range includes Indonesia, northern New Guinea and nearby island groups, Vanuatu, and New Caledonia. Typical sites have relatively gentle gradients, broad slow-to-moderate runs, pools, and occasional small cascades. Clear oxygen-rich water passes over bedrock and scattered stones that support substantial biofilm.

Aquarium setup

Start with a stable, mature aquarium. Set larger rocks securely on the base before adding sand or gravel, because digging fish can undermine unsupported stonework. Provide varied rocks, retreats, and interrupted sightlines. Males burrow when resting or spawning and may change sleeping sites.

Lighting should support algal growth. Seasoned wood and hardy attached plants are optional, but heavily staining new wood can reduce light penetration. Maintain filtration, aeration, and circulation, and cover openings against climbing fish. Weekly changes of roughly 30–50% are important; stripping every surface of algae is not.

Diet & feeding

This is an algal grazer that also consumes the microorganisms living with the algae. Accepted sinking foods or small meaty items are occasional supplements. If grazing material runs short, grow algae on stones in a separate well-lit container and rotate them into the aquarium. Softer films are preferred to tough black brush algae.

Inspect prospective purchases for weight loss. Severely thin fish can be difficult to recover and need ready access to appropriate food without strong competition.

Behaviour & compatibility

Choose peaceful, similarly sized companions suited to oxygen-rich conditions. Exclude aggressive feeders, large fishes, and most territorial bottom-dwelling cichlids. Males defend space, especially around breeding, so several need sufficient room and feeding surfaces. A male with at least two females is a suggested small group; females associate more loosely.

Sexual dimorphism

Males are blackish, with posterior vertical bars more visible in smaller individuals, and some first-dorsal spines extend. Females have a pale background, a broad dark lateral stripe that breaks into posterior blotches, and a thinner stripe above it.

Breeding

The genus reproduces in freshwater, but tiny larvae drift to sea and return inland after development. Male guarding beneath rocks has been observed within the group. Completing the marine larval phase is the major obstacle; developmental timings, egg counts, and speculative longevity from other species should not be assigned to this one.

Notes

A few private collectors have maintained this fish, rather than it being a routine commercial offering. Male darkness is useful for identification, but locality and structural characters remain relevant.