Wrestling Halfbeak Fish (Dermogenys pusilla)

Wrestling Halfbeak

Last updated on September 9th, 2022 at 05:04 pm

Dermogenys pusilla, more commonly known as the Wrestling Halfbeak fish or the Malayan halfbeak fish, are unique fish that are native to South East Asia. Although they don’t make great pets, they can be observed and studied in their natural habitat by underwater divers and swimmers. It’s not uncommon to see these halfbeaks in shallow water near the shoreline where they feed on small insects and vegetation.

The endangered species of Dermogenys pusilla should never be picked up or handled as they have very sharp needle-like teeth that can cause a great deal of pain if they make contact with human skin.

Dermogenys pusilla is a small freshwater ray-finned fish in the family Zenarchopteridae, native to eastern and southeastern Asia and Australia. In the wild, they are found in moderately flowing streams, canals, ditches, and ponds with abundant vegetation and water weeds.

Your typical Wrestling Halfbeak fish can be quite feisty, and can often be seen wrestling with other Halfbeak fish in an effort to win the females’ attention. If you ever find yourself around a Wrestling Halfbeak, these are some tips that may be useful to you.

Origin and descriptions

Wrestling Halfbeak

Wrestling Halfbeak is native to fresh and brackish waters from Japan, China, and Korea south to Australia. The species is considered highly invasive in southern Africa. The halfbeak is a fish of coastal freshwater and estuarine habitats, but it can also enter marine waters at high tide in some parts of its range.

It prefers relatively shallow water with mud bottoms or silt beds and aquatic vegetation such as seagrass or mangroves. Its diet consists mainly of small invertebrates, including crustaceans, insects, and worms. Reproduction occurs year-round in warmer climates; elsewhere there are distinct breeding seasons for different age groups.

Most populations are thought to be between one and three years old when they reach sexual maturity. In most areas they spawn once per year; however, multiple spawns may occur under favorable conditions. Fecundity varies widely among populations depending on environmental factors; estimates range from 10,000 to 2 million eggs per female.

Poecilia mexicana (Shortfin Molly Fish)

Species profile

Wrestling Halfbeak fish belongs to the family Zenarchopteridae. The word halfbeak refers to its long lower jaw, which is actually a modification of its upper jaw. It has two pairs of teeth: incisors and molars. The species was first described by George Cuvier in 1829 based on specimens collected from India and Sri Lanka.

This species is also known as Spatula-toothed halfbeak or Indian spadefish. They are mostly found in brackish waters along the coasts of Asia. They are bottom dwellers and live among seaweed fronds where they feed on small crustaceans, worms, insects, and other small invertebrates.

These fish can grow up to 3 inches long but most only reach around 2.5 inches. They have very sharp teeth that they use for catching their prey.

Scientific name

The scientific name of the wrestling halfbeak is Dermogenys pusilla


Wrestling Halfbeak fish are found in freshwater and brackish water areas of Florida, Texas, Mexico, Central America, and northern South America. In fact, Dermogenys pusilla is one of five species that are native to the southern United States. They can be found swimming in lakes, marshes, and shallow streams.

They spend their days foraging for food and eating small invertebrates like insects or crustaceans that live on rocks or vegetation along stream banks. At night, they hide under large rocks or logs. This makes them hard to spot by predators because they blend into their surroundings so well. That’s why you may not have noticed them if you’ve ever gone fishing at night!

Wrestling halfbeak size

Wrestling Halfbeak

The males of these fish species can only grow to around 2.2 inches (5.5 cm) in length, while the females are larger than the males and grow up to 3 inches (7 cm) in length.

Wrestling halfbeak tank size

The minimum recommended tank size for this fish species is 20 gallons (76 liters)

Tank requirements

The tank should be at least 20 gallons and should be filtered. The halfbeaks are surface swimmers, so your tank should have a lid to keep them from jumping out. They can jump up to six inches vertically and three inches horizontally. They prefer warm water, ranging from 78 to 84 degrees Fahrenheit, but they can tolerate temperatures down to 65 degrees Fahrenheit for short periods of time.

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It is best to keep them in water that is slightly acidic with a pH between 6.5 and 7.5. Halfbeaks need plenty of hiding places, such as plants or caves made from smooth rocks or driftwood. These fish like bright lighting; you can use fluorescent lights or even sunlight if you don’t mind keeping your aquarium uncovered during daylight hours.

You will also need an air pump and an air stone to provide oxygenation. Halfbeaks eat a variety of foods, including flakes, pellets, live worms, and insects. You may also want to add algae wafers into their diet. However, make sure you feed them only what they can consume within five minutes because any leftovers will pollute their water quickly.

Tank mates

The popular choices for a freshwater tank are other livebearers, smaller rainbowfish, and freshwater gobies. However, for a brackish tank, you can also keep bumblebee gobies, glassfish, and mollies.


Wrestling Halfbeak

Even though it is possible to breed more livebearers, it isn’t as easy. Breeding these fish is not difficult, it’s just that many of the females give birth to stillborn fry. This is directly related to the diet of the fish (some authors speculate that vitamin D deficiency is responsible), so make sure you provide them with a high-quality diet.

For breeding purposes, you should keep them together in a species setup. Providing the tank with plenty of surface vegetation, conditioning the fish well, and providing plenty of surface vegetation will ensure that mating will not be a problem.

Temperature influences the length of pregnancy, which ranges from 3-6 weeks. Unless the fry are unhealthy, it is best to remove them as they may be preyed upon by the adults. In terms of feeding and raising, they are quite easy to handle, requiring neither powdered dry food nor brine shrimp nauplii from birth. Brood sizes usually range from 10 to 20.

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Are they aggressive or peaceful?

Wrestling Halfbeak fish are peaceful fish. A lot of anglers are worried that they will be attacked by a halfbeak fish. The truth is, Wrestling Halfbeak rarely bite, and they are non-aggressive towards people. They’re very easy to tame, which makes them an excellent option for novice fishermen.

Wrestling halfbeak care

Wrestling Halfbeak

Wrestling halfbeak is relatively easy to care for, but there are a few things to keep in mind. Firstly, they need to be kept in groups of at least six individuals. When kept alone, they can become very shy and skittish. Secondly, they prefer cool water that’s slightly acidic with a pH between 6.5 and 7.0; ideally, you should use spring water or tap water that has been conditioned with an aquarium water conditioner.

You can also add peat moss to your tank, which will help lower your pH levels. Finally, it’s important to provide plenty of hiding places for these little guys; some good options include plastic plants and hollowed-out clay pots. They also enjoy having live plants like Java fern in their tank as well as gravel substrate instead of sand because it helps them find food more easily.

Wrestling Halfbeak diet

Make sure to feed them a variety of foods, including high-quality flakes and frozen brine shrimp and daphnia. They also enjoy live or frozen bloodworms as treats. You’ll want to feed them regularly; once a day is enough if you have young fish, but adults will eat several times per day.

Wrestling halfbeak lifespan

They can live up to 4 years if taken care of properly.

Parasites and diseases

Because of its small size, Wrestling Halfbeak is susceptible to internal and external parasites. It’s relatively hardy in terms of disease resistance, but it must be quarantined for a period prior to introduction into an aquarium. External parasites like the anchor worm can adversely affect D. pisillus, as can protozoan infections like ich and costia.

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Common bacterial diseases include red pest and columnaris; both are readily treatable with antibiotics such as kanamycin and erythromycin. A number of fungal diseases afflict halfbeaks, including cryptocaryoniasis (an infection caused by dinoflagellates), chilodonella, and trichodina.

These conditions are difficult to diagnose because they manifest in similar ways across multiple species; treatment typically involves broad-spectrum antibiotic therapy or salt baths.


There are few natural predators of adult Wrestling Halfbeak; most die of old age. Some larvae, fry, and juvenile halfbeaks fall prey to a variety of fish, aquatic insects, and crustaceans. Frogs, turtles, and larger fishes also eat baby halfbeaks. Large piscivorous fishes like barracuda also prey on them, as do birds like gulls that feed on schools of young halfbeaks. Aquatic mammals like otters will also eat them occasionally.

Do Wrestling Halfbeak make good pets?

Despite their colorful appearance, halfbeaks aren’t especially attractive to keep as pets. They’re fine if you want to spend some time with them in a fish tank but they aren’t really interactive. Because they swim low in the water and stick together in schools, they can be tricky to handle because they don’t like being handled. Most people who do get one just love watching it move and swim around their tank.

If you want to keep one of these interesting fish for a pet, make sure that it was caught in your local freshwater aquarium and not taken from a natural body of water. The International Union for Conservation of Nature lists Dermogenys pusilla as being vulnerable to extinction due to collection by hobbyists.