Betta Imbellis

Datasheet

General Description

The Crescent Betta, scientifically known as Betta Imbellis, is a species within the genus Betta that has been selectively bred for aggression in southern Thailand. This species is often used in organized fighting bouts and is also popular in the ornamental trade. Betta Imbellis exhibits various color forms that do not occur naturally, with differences in coloration and patterning based on their locality within regions like Penang Island and Selangor. The species is a bubble nester and, like other Betta species, possesses an accessory breathing organ known as the labyrinth, allowing it to breathe atmospheric air.

Aquarium Setup

The optimal tank setup for Betta Imbellis includes a well-planted and shaded aquarium with plenty of surface cover, such as tall stem plants, floating vegetation like Salvinia, and tropical lilies. Driftwood, clay plant pots, and plant attachments to structures provide additional shelter. Dried leaf litter can be added for cover and as a food source for fry. Gentle water movement from an air-powered sponge filter is recommended, and the tank should not be filled to the top to allow access to the layer of humid air above the water surface.

Behaviour

Betta Imbellis is not suitable for a standard community aquarium due to its care requirements and disposition. It is best kept alone or with very peaceful species. While multiple males can be housed together with sufficient cover, it is recommended to isolate pairs for breeding purposes. This species can be territorial, especially during breeding, and caution should be exercised when introducing new fish to their environment.

Feeding and Diet

In nature, Crescent Bettas prey on aquatic and terrestrial invertebrates. In captivity, they readily accept dried foods but should be offered live or frozen foods like Daphnia and Artemia regularly to maintain optimal color and condition. Overfeeding should be avoided as Bettas are prone to obesity.

Reproduction & Dimorphism

During reproduction, the male Betta constructs a bubble nest and embraces the female for spawning. Males are more colorful and develop extended fins as they mature. After spawning, the male guards and tends to the nest, while the female's involvement decreases. The fry hatch in 24-48 hours and are initially fed infusoria-grade food before transitioning to microworms and Artemia nauplii.

Habitat and Distribution

Betta Imbellis is native to southern Thailand, Peninsular Malaysia, and northern Sumatra, with feral populations established in areas like Singapore. They inhabit still and sluggish waters, including rice paddies, swamps, and roadside ditches, often shaded by vegetation. Some populations can be found in brackish coastal swamps. The introduction of ornamental forms and other Betta species to their habitats can negatively impact wild populations.