Wrestling Halfbeak

Overview

The Wrestling Halfbeak (Dermogenys pusilla) is a quirky surface-dwelling livebearer with a long lower jaw; a keen jumper. It is a popular choice among Australian aquarists, reaching around 7 cm and living roughly 2-3 years when properly cared for.

This complete guide covers how to keep the Wrestling Halfbeak successfully - tank size and setup, water parameters, the best foods (including recommended brands), suitable tank mates, breeding, sexing and the health issues to watch for. It is rated Intermediate to care for.

Natural Habitat & Origin

This species comes from tropical freshwater habitats and does best when its tank reflects the conditions it evolved in.

Matching the temperature, water chemistry and cover a species evolved with is the simplest route to keeping it healthy and seeing its natural behaviour and colour.

Tank Size & Aquarium Setup

Provide a minimum of 60 litres for the Wrestling Halfbeak. As a group-living species, swimming length and floor space matter more than height.

Live plants, driftwood and shaded retreats give security and show off the fish's colours against a natural backdrop.

Always add fish only to a fully cycled, mature tank with stable biological filtration. Match filtration generously to the fish's size and waste output.

Water Parameters

Keep the Wrestling Halfbeak in stable water at 22-28 °C with a pH of 7.0-8.0. It adapts to a moderate range, so stability matters more than an exact figure.

Test regularly: ammonia and nitrite must read zero, and nitrate should be kept low with routine partial water changes. Always dechlorinate and temperature-match new water, because sudden swings cause far more illness than water that is stable but slightly imperfect.

Diet & Feeding

The Wrestling Halfbeak is a carnivore and needs a protein-rich, meaty diet.

In Australia, good options include Hikari Carnivore pellets or Vibra Bites, plus Dymax frozen bloodworm, daphnia and brine shrimp. Feed small amounts once or twice a day (only what is cleared in a minute or two), vary the diet for the best colour and health, and avoid overfeeding, which is the leading cause of poor water quality.

Temperament & Tank Mates

The Wrestling Halfbeak is semi-aggressive: generally community-tolerant but territorial at times, especially when breeding or under-stocked. Avoid very small, slow or long-finned tank mates and give everyone space.

It is happiest in a group of its own kind and is shyer and less settled when kept alone.

Breeding

The Wrestling Halfbeak is a livebearer - females give birth to free-swimming young with no special effort. Provide dense cover so some fry survive.

Even if you are not planning to breed it, recognising this behaviour helps you understand what you are seeing and respond well - for example by adding cover for fry or giving a guarding pair extra space.

How to Tell Males from Females

Differences between the sexes are subtle and most obvious in mature fish in breeding condition.

Common Health Problems

Like most aquarium species it can suffer from white spot (ich), fin rot and fungal or bacterial infections, almost always triggered by stress or poor water quality. Quarantine new arrivals for 2-4 weeks and watch daily for early signs such as loss of appetite, unusual hiding, clamped fins or laboured breathing - caught early, most issues are very treatable.

Prevention beats cure: keep water pristine, avoid overstocking and overfeeding, quarantine new arrivals, and act at the first sign of trouble.

Is the Wrestling Halfbeak Right for You?

The Wrestling Halfbeak suits keepers with some experience and a stable, mature, appropriately sized tank, as long as you can provide at least 60 litres, water at 22-28 °C and pH 7.0-8.0, the right diet and a proper group of its own kind.

Meet those needs and the Wrestling Halfbeak will reward you for around 2-3 years. Use our free aquarium calculators to plan your setup, and explore our other fish, plant and disease guides to build a thriving aquarium.

Frequently Asked Questions