Belontia Hasselti

Datasheet

General Description

The Belontia Hasselti, commonly known as the Java Combtail, is a species of labyrinth fish belonging to the family Osphronemidae. It is native to southern Indochina, specifically found in regions ranging from southern Thailand to Java, Indonesia. This species, also referred to as the 'Malay Combtail,' exhibits a brownish-grey body coloration and features a mosaic-type pattern in its unpaired fins.

Aquarium Setup

To replicate its natural habitat, an aquarium setup for the Java Combtail should include adequate hiding spots and structures such as ceramic flowerpots, plastic piping, and wood roots. The addition of dried leaf litter, specifically beech, oak, or Ketapang almond leaves, can create a natural feel and encourage the growth of beneficial microbe colonies. Plants like Microsorum, Taxiphyllum, Cryptocoryne, and Anubias are recommended, along with dim lighting and some floating vegetation to diffuse light. It is advisable to avoid strong filtration, maintaining a gentle water flow to simulate the fish's sluggish or still environment.

Behaviour

While not suited for standard community tanks, the Java Combtail can coexist with other fish in larger setups, preferably with medium-sized schooling cyprinids or robust anabantoids. Belontia species are not gregarious and are often aggressive towards conspecifics, particularly during spawning. Introducing new specimens should be done with caution, as aggression can lead to fatal outcomes.

Feeding and Diet

Primarily carnivorous, the Java Combtail feeds on invertebrates, molluscs, and small fish in its natural habitat. In captivity, it consumes larger live and frozen foods like earthworms and shellfish, eventually accepting dried alternatives such as pellets. Smaller food items like chironomid larvae and Artemia are suitable for juveniles but may be ignored by adults.

Reproduction & Dimorphism

The Java Combtail is a paternal bubble nester, displaying high fecundity. Fully-grown males are larger than females and possess elongated unpaired fins. However, sexing juveniles externally is challenging. Specific details regarding the reproduction of this species are not extensively documented.

Habitat and Distribution

This species predominantly inhabits acidic freshwater biotopes with minimal water movement, particularly in ancient forest peat swamps. Found in regions of southern Indochina, including Peninsular Malaysia, Singapore, and the Greater Sunda Islands, the Java Combtail thrives in environments characterized by dark, humic acid-stained water, a low dissolved mineral content, and pH levels as low as 3.0-4.0.