Rhinogobius chiengmaiensis · Chiangmai Stream Goby

Overview

Rhinogobius chiengmaiensis is a small Thai stream goby often mislabeled as a relative. Clean, oxygen-rich moving water and opportunities for conspecific interaction are important. Male territoriality is not a reason to assume that permanent solitary housing is best.

Distribution & habitat

Known records are restricted to the middle and upper Chao Phraya system, including the Ping and Nan. Chiang Mai is the type locality.

It occupies small rivers and streams over gravel, rocks, boulders, and exposed bedrock. Flow, depth, and turbidity change seasonally. Aquatic plants are usually absent, though banks and overhanging vegetation may be densely grown.

Aquarium setup

Combine varied rocks, sand, and fine gravel with wood, ceramic tubes, or pots to provide shaded crevices and interrupted sight lines. Hardy Java fern, Bolbitis, or Anubias can be attached to the furnishings.

Prevent organic waste accumulation with weekly changes of roughly 30–50%. High oxygen levels and some movement are essential, without requiring torrent-like flow throughout. Supplement filtration with circulation or aeration as needed.

Diet & feeding

Related Rhinogobius are generally opportunistic animal feeders. Offer small live or frozen bloodworms, mosquito larvae, Artemia, water fleas, or mysids. Dry foods may eventually be accepted but should not form the regular staple.

Behaviour & compatibility

Peaceful, similarly sized upper-water fishes adapted to current are suitable candidates. Avoid large fishes, forceful feeders, and territorial bottom-dwelling cichlids. Small stream loaches or other gobies require individual assessment rather than automatic approval as fellow stream inhabitants.

Do not mix other Rhinogobius for breeding while their hybridization potential remains unresolved. Small freshwater shrimp may be eaten.

Males defend space, but serious injury is unlikely with ample cover. At least two males with an equal or greater number of females is recommended; fish without enough conspecific company may become inactive.

Sexual dimorphism

Adult males show stronger color and slightly extended dorsal and anal fins.

Breeding

It can reproduce year-round in aquaria and is comparatively straightforward within the genus. Wild breeding has been recorded in May–August and December–March, rather than establishing compulsory aquarium months.

Eggs adhere to the roof of a cave or crevice, with the male guarding until hatching. Offer several sites using flat stones, tubes, or pots. A male selects and defends one, sometimes excavating beneath a rock if suitable shelter is unavailable.

A pair may remain hidden for two to three days and should be left undisturbed. After the female is expelled, inspect by gently tilting the shelter underwater rather than exposing the eggs to air.

Inexperienced parents may eat eggs, attach them poorly, or achieve incomplete fertilization, often improving with repeated attempts. Remove other fishes after spawning, or transfer the male and eggs together using a small container.

Clutches usually contain twenty to sixty relatively large eggs. Incubation takes about nine to eleven days, with no free-drifting larval phase. Newly hatched fry retain a substantial yolk sac and can already be offered Artemia nauplii or microworms.

Notes

Compared with the commonly confused Rhinogobius mekongianus, this fish has five irregular body marks rather than seven or eight, plus more numerous finer male cheek and opercular spots. Combine these features with trustworthy locality information.

The genus contains both landlocked and migratory reproductive strategies. Larval salinity requirements of another species should not be transferred automatically to this one.