Brachygobius mekongensis · Mekong Bumblebee Goby

Overview

The minute freshwater Brachygobius mekongensis has narrow, frequently interrupted dark bars. Other bumblebee gobies are sometimes sold under its name. A striped appearance alone is insufficient reason to add salt or transfer another species' care routine.

Distribution & habitat

Records extend along the middle and lower Mekong from Vientiane and Nong Khai south to Vietnam and Cambodia, including Tonlé Sap. The type area lies near the Xe Champhon in Savannakhet, Laos.

It appears restricted to slow or standing fresh water in marshes, seasonal wetlands, and floodplains with dense aquatic vegetation or flooded grasses. At one lightly stained, Vallisneria-rich marsh, fish favored water around 30–50 cm deep and fed mainly on small aquatic insects and zooplankton.

Aquarium setup

Dense plants, floating cover, roots, and fine branches provide an appropriate setting. Keep filtration gentle; an air-powered sponge is suitable. The aquarium must be mature before introduction.

Diet & feeding

Small aquatic animals form its diet. Live Artemia and tiny water fleas should be considered basic provisions. Some individuals learn to take frozen alternatives, whereas dry foods are usually ignored. Offering microgranules alone is not a dependable acclimation strategy.

Behaviour & compatibility

A dedicated aquarium is preferable, with any companions limited to similarly tiny, gentle fishes needing compatible conditions.

Males in particular defend space against each other, yet six or more are recommended. A sufficient group distributes conflict and promotes confidence and natural behavior; territoriality does not automatically make solitary housing preferable.

Breeding

Aquarium spawning has been recorded, with roughly thirty eggs attached to a hard surface and tended by the male. Successful rearing of the fry remains uncertain.

Wild growth studies found very early maturity: the youngest mature females were about fifty-four days old in dry-season samples and thirty-six days in wet-season samples. Gravid females in both seasons suggest year-round spawning, rather than guaranteeing a fixed maturation age for every brood.

Notes

Compared with Brachygobius nunus, the bars are narrower and often broken, with a short oblique mark between the dorsal fins. Parts of the head and underside are naked, but the remaining body bears ctenoid scales; this is not a wholly scaleless fish.

Identification within the genus and trade labeling remain problematic. Assess pattern details and reliable locality information together.