皮颏鱵 · Wrestling Halfbeak

Overview

The extended lower jaw and male jaw-locking contests characterize Dermogenys pusilla. It spends nearly all its time just below the surface and can be very nervous after introduction. Broad surface space, planted margins, and secure containment are more important than aquarium depth.

Distribution & habitat

Records extend from India and Myanmar through Thailand, Laos, Cambodia, Vietnam, the Philippines, Malaysia, and Indonesia. Still or slowly moving rivers, canals, ditches, flooded fields, lakes, and ponds typically offer abundant surface vegetation. Slightly brackish mangrove waters are occasionally used during the rainy season.

Aquarium setup

A small group can occupy an aquarium from approximately 60 by 38 by 30 cm, around 68 L. Dense planting along the sides reduces the chance of delicate mouthparts striking glass during a fright. Floating vegetation complements a tight-fitting cover against jumping. Furnishings below the surface are largely optional.

Hard, moderately alkaline freshwater is suitable; marine salt is not obligatory. A lightly brackish arrangement around specific gravity 1.005 is another option. Use frequent small water changes because both deteriorating conditions and abrupt temperature or chemical shifts are poorly tolerated.

Diet & feeding

All feeding occurs at the surface. Nutritionally conditioned fruit flies are useful, alongside accepted brine shrimp, bloodworms, and similar foods. Dry preparations may be refused initially but are often accepted after acclimation. Confirm consumption rather than assuming that introduced food reaches the fish.

Behaviour & compatibility

Choose peaceful fishes of similar size and matching water requirements. Other livebearers, small rainbowfishes, or freshwater gobies may suit freshwater arrangements; brackish companions must tolerate the same salinity. Large or aggressive fishes readily intimidate and outcompete it.

A group usually reduces nervousness. Males spar, but lasting injury is uncommon when sufficient room allows withdrawal. Keep either one male or several with adequate space to distribute attention, rather than confining a few rivals together.

Sexual dimorphism

Males are much smaller, with the anal fin modified into a mating organ. Mature males also carry a red dorsal-fin patch absent from females.

Breeding

Captive reproduction is possible, though producing healthy newborns can be harder than inducing mating. Stillbirths have been associated with nutritional problems; proposed specific deficiencies should not be treated as the sole established cause.

Condition a group in a species aquarium with abundant surface plants. Pregnancy varies with temperature and commonly lasts three to six weeks, producing about 10–20 young. Healthy fry immediately take fine powdered food and newly hatched brine shrimp. Remove them from the adults to reduce predation risk.

Notes

Jaw-locking is rivalry rather than a reason to force fights in confined containers. Several similar halfbeaks share trade names, so a sales label alone cannot reliably identify a specimen.