LABYRINTH FISH

Labyrinth fish belong to the suborder Anabantoidei, which includes (with some taxonomic debate) five families: Anabantidae, Belontiidae, Helostomatidae, Luciocephalidae (controversially), and Osphronemidae. These fish are found across Africa, India, and Southeast Asia, where they inhabit a variety of freshwater environments.

The name "Labyrinth fish" comes from the Labyrinth Organ, a specialized respiratory structure that allows these fish to extract oxygen directly from the air. This adaptation enables them to survive in oxygen-deprived waters where other fish might struggle. The organ is located above the gills and consists of highly folded skin tissues lined with blood vessels, enhancing oxygen absorption. Due to this adaptation, certain species, such as Anabas testudineus (the climbing perch), can leave the water for extended periods in humid conditions and even move across land using their pectoral fins.

Size

Labyrinth fish range from small to medium-sized species. While some, like dwarf gouramis, stay under 3 inches (7.5 cm), others, such as the giant gourami (Osphronemus goramy), can grow well over 18 inches (45 cm) in captivity.

Habitat

These fish primarily inhabit stagnant or slow-moving waters such as swamps, rice paddies, and floodplains, where oxygen levels are often low. The majority of labyrinth fish species are found in Asia, India, and Southeast Asia, while one family is native to Africa. Their ability to breathe atmospheric oxygen allows them to thrive in environments that other fish might avoid.

Swimming Level

Swimming habits vary by species, with some preferring the surface, others staying in mid-water, and some inhabiting the lower regions of the tank.

Tank Requirements

Because labyrinth fish encompass a diverse range of species, it is difficult to generalize their tank requirements. However, certain elements apply to most species:

• Provide plenty of hiding places, such as plants, driftwood, and caves.
• Many species prefer calm waters with little or no current.
• A secure tank lid is essential, as these fish frequently gulp air from the surface and can jump out.

Water Conditions

Due to their wide distribution, labyrinth fish exhibit varying water condition preferences. However, most thrive in:

• pH: 6.0 - 7.5
• Water Hardness: 4-15 dH
• Temperature: 72-82°F (22-28°C)

Social Behavior

Although most labyrinth fish are peaceful and suitable for community tanks, some species can be aggressive. Males, especially bettas and gouramis, are often territorial and may harass females or other males, particularly during spawning.

Compatible Species

Tankmates vary depending on the species. See individual descriptions for specific compatibility guidelines.

Diet

Labyrinth fish are generally omnivorous, accepting a variety of foods, including:

• Live foods such as brine shrimp, daphnia, and mosquito larvae
• High-quality flake and pellet foods
• Vegetable-based foods, especially for gouramis

Breeding

Labyrinth fish have developed different reproductive strategies to adapt to their environments. These include:

• Bubble-nest builders: Males construct nests at the water's surface using bubbles coated in saliva. Spawning occurs beneath the nest, after which the male collects the eggs and places them in the nest. He aggressively guards the territory, often driving away even the female.
• Mouthbrooders: After spawning, one parent (usually the male) takes the eggs into its mouth for incubation. The fry are later released when they are free-swimming.
• Open-water spawners: These species scatter their eggs freely in the water, providing no parental care. The eggs drift until hatching.

Breeding Difficulty

The difficulty of breeding labyrinth fish depends entirely on the species. While bettas and gouramis readily breed in captivity, some species require more specific conditions to trigger spawning.

Difficulty Level

Labyrinth fish cater to a wide range of aquarists, from beginners keeping hardy species like bettas to experienced keepers maintaining larger and more complex species.