# Betta (*Betta splendens*)

> The betta or Siamese fighting fish (Betta splendens) is a labyrinth fish from shallow Mekong-basin waters in Thailand, Cambodia, Laos, and Vietnam. Wild fish breathe air at the surface and eat insects and zooplankton; males build bubble nests. Captive strains are famous for vivid fins, while wild populations are listed Vulnerable.

- **Category:** Fish
- **Conservation status (IUCN):** Vulnerable
- **Range:** Shallow freshwater of the lower Mekong basin in Thailand, Cambodia, Laos, and Vietnam.
- **Canonical page:** https://globalanimalguide.org/animals/betta/
- **Last reviewed:** 2026-07-16

## Scientific classification

- **Kingdom:** Animalia
- **Phylum:** Chordata
- **Class:** Actinopterygii
- **Order:** Anabantiformes
- **Family:** Osphronemidae
- **Genus:** Betta

## Facts at a glance

| Attribute | Value |
| --- | --- |
| Scientific name | Betta splendens |
| Diet | Carnivore (insects and zooplankton) |
| Habitat | Rice paddies, ponds, and slow streams |
| Lifespan | Around 3 years in the wild (varies by population and captivity). |
| Weight | About 0.003 kg typical adult mass (sex and region vary). |
| Top speed | Up to roughly 5 km/h when moving at speed. |
| Conservation status | Vulnerable (IUCN) |

## Labyrinth organ and bubble nests

Bettas gulp air into a labyrinth organ, surviving oxygen-poor rice paddies and ditches. Males build floating bubble nests and fiercely guard eggs and fry. Long-finned aquarium forms were selectively bred; wild-type fish have shorter fins.

## Insects in still water

Wild diet centres on mosquito larvae, other aquatic insects, and zooplankton. They are carnivores, not algae eaters — overfeeding plant matter in captivity causes health problems.

## Lower Mekong shallows

Native range is shallow freshwater of the lower Mekong basin across Thailand, Cambodia, Laos, and Vietnam — rice paddies, ponds, and slow streams with dense vegetation.

## Vulnerable wild stocks

IUCN lists wild Betta splendens Vulnerable. Urbanisation, water pollution, and hybridisation with released aquarium fish threaten remaining wild populations even as captive fish remain globally common.

## Frequently asked questions

### Why do bettas breathe air?

A labyrinth organ lets them extract oxygen from air, which is vital in warm, stagnant paddies where dissolved oxygen is low.

### Do male bettas really fight?

Yes — territorial males flare gills and fins and will bite rivals; that is why they are usually kept singly in home aquaria.

### What should wild-type bettas eat?

Insects and zooplankton — mosquito larvae and similar prey — not flake food alone.

### Are wild bettas endangered?

Wild Betta splendens is Vulnerable; colourful pet-shop fish are captive-bred and not a substitute for wild conservation.

### Where do bettas come from originally?

Shallow freshwaters of the lower Mekong region in Thailand, Cambodia, Laos, and Vietnam.

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Source: Global Animal Guide (https://globalanimalguide.org/animals/betta/). Licensed CC BY-NC 4.0 — free for non-commercial reuse with attribution.