Aquarist Atlas
Aquarist Atlas · the genus Betta

Wild Bettas

Behind the flowing-finned fish of the pet-shop cup sits a wild genus of remarkable range — Betta, the fighting fishes of Southeast Asia. Around ninety valid species live in the still and slow waters of the region: the bubble-nesting splendens group of mainland rice paddies and ditches, the jewel-red dwarfs of the Sundaic peat swamps (the coccina and bellica groups), and a whole parallel radiation of paternal mouthbrooders — the pugnax, picta, unimaculata, waseri and akarensis groups — that carry their eggs in the throat rather than under a raft of bubbles. This section is an atlas of those wild species, built to the same standard as the cichlid, cory and pleco pages: researched, cited accounts with no Wikipedia and no invented facts. It is about the fish as they live in the wild, not the colour strains of the domesticated B. splendens.

© Adobe Stock

Two reproductive strategies cut across the genus and shape almost everything about how a species is kept: bubble-nesters, where the male builds and guards a raft of mucus-bound bubbles at the surface, and paternal mouthbrooders, where the male incubates the eggs and fry in his mouth for one to two weeks. Each species' page records which mode it uses, alongside its water chemistry — because many wild bettas are blackwater specialists of soft, acidic, tannin-stained swamp water that the domesticated fish has long left behind. The fancy halfmoon, plakat and koi strains belong to the aquarium-strain story, not to a wild species.

A wild male fighting fish in full display, fins spread, iridescent scales catching the light against dark water
A displaying male flares his gill covers and unfolds his fins — the threat display that gave the fighting fish its name. In the wild it settles most disputes without contact.
A wild-type betta with short rounded fins and barred, earth-toned colouration over dark water
Wild bettas are short-finned and cryptically coloured — the long veils and saturated colours of pet-shop fish are products of a century of selective breeding.
A wild betta over a dark substrate, body striped, fins edged in colour, in a quiet blackwater setting
Most wild species live in still, shallow, oxygen-poor water and breathe air through the labyrinth organ — which is why a betta can survive a drying ditch or a peat swamp.

Photos © Adobe Stock

78 species in the atlas

The genus Betta holds roughly ninety valid species under the Catalog of Fishes, and the count keeps rising as Sundaic peat swamps and Bornean drainages are surveyed. New accounts are added as those species are written up. Wild bettas are also one of the most threatened freshwater groups in Southeast Asia: peat-swamp clearance and drainage have pushed many single-swamp endemics onto the IUCN Red List.

Species

78 of 78 species

splendens group · 6

The fighting bettas of mainland Indochina — splendens, smaragdina, imbellis, mahachaiensis and kin. Bubble-nesters of rice paddies, ditches and still margins; the source of the domesticated Siamese fighting fish.

coccina group · 12

The small, jewel-red bubble-nesters of Sundaland peat swamps and blackwater — coccina, brownorum, tussyae, livida, persephone and allies. Many are tied to a single threatened swamp forest.

bellica group · 2

Slim, elongate bubble-nesters of the Malay Peninsula and Sumatra (bellica, simorum) — larger and more streamlined than the coccina dwarfs.

pugnax group · 14

The widespread Sundaland mouthbrooders — the 'pugnax' or 'penang mouthbrooder' assemblage. Paternal mouthbrooders of forest streams across the Malay Peninsula, Sumatra and Borneo.

picta group · 5

Small paternal mouthbrooders of Java, Sumatra and the peninsula (picta, falx, taeniata, simplex) — the 'spotfin' bettas of clear forest brooks.

unimaculata group · 8

Robust Bornean mouthbrooders — unimaculata, ocellata, macrostoma (the Brunei beauty), patoti and kin. Several are large, boldly marked stream fish.

waseri group · 10

Big-headed peat-swamp mouthbrooders of the Malay Peninsula (waseri, hipposideros, tomi, pi, chini, pardalotos). Specialists of acidic blackwater, many highly threatened.

akarensis group · 9

Bornean mouthbrooders of the Akar and allied drainages (akarensis, antoni, aurigans, balunga, ibanorum, obscura, pinguis) — slender stream species.

albimarginata group · 2

Tiny Bornean mouthbrooders with white-edged fins — albimarginata and channoides. Cool, clear hill streams of eastern Borneo.

anabatoides group · 2

Large Bornean mouthbrooders (anabatoides, midas) — heavy-bodied 'giant' bettas of lowland forest waters.

dimidiata group · 2

Small bettas of Borneo (dimidiata, krataios) — slim, lively fish of clear peaty streams.

edithae group · 1

The wide-ranging Betta edithae and its kin — adaptable mouthbrooders of Sumatra and Borneo, often the first wild betta a swamp survey turns up.

foerschi group · 3

Bornean mouthbrooders with bright opercular bars — foerschi, mandor, strohi. Blackwater and peat-swamp specialists of southern and western Borneo.

rubra group · 2

The Sumatran red mouthbrooders — B. rubra and B. dennisyongi — of northern Sumatra (the Lake Toba region and Aceh). Split from the foerschi group by Tan (2013).