SNAKEHEADS (CHANNIDAE)

Eight species of snakehead occur in the Mekong basin, all belonging to the genus Channa. Only two of these are currently used in significant numbers for aquaculture namely the giant snakehead (Channa micropeltes) and the Chevron snakehead (Channa striata).

Life cycle of snakeheads

Snakeheads generally live in still or slow-flowing waters throughout the Mekong basin. Contrary to the Pangasiid catfishes described above, they do not undertake long distance migrations, but instead make shorter lateral migrations between rivers and nearby floodplains, following the hydrological cycle of the monsoonal, floodplain river ecosystem.
Snakeheads are opportunistic breeders that can spawn whenever conditions are right. In the wild they normally spawn during the monsoon season, i.e. from May to September. They lay a small amount of floating eggs in a small nest made of vegetation. The male guards the nest, and later the fry – a behaviour that is used by experienced fishers to collect the fry for stocking in grow-out cages.

Chevron snakehead, Channa striata

The Chevron snakehead, Channa striata, is one of the most common fish in the lower Mekong basin (Figure 5). It is air-breathing and is able to live in very shallow waters and is therefore particularly well adapted to life in rice farming landscapes and ecosystems (Amilhat and Lorenzen, 2005). It moves seasonally between open-water, perennial habitats (lakes, swamps, rivers) and seasonal floodplain and rice field habitats, where spawning, nursing and feeding takes place during the monsoon period from May to October.
The long association with man-made habitats have in some places resulted in the emergence of habitat management interventions by rice farmers aimed at increasing the yield from Chevron snakehead fisheries, e.g. by making small perennial “trap ponds” within the rice farming ecosystem (Amilhat and Lorenzen, 2005).

Figure 5
A specimen of Channa striata

Giant snakehead, Channa micropeltes

The giant snakehead has a similar life cycle to the Chevron snakehead and is also distributed throughout the lower Mekong basin. It moves seasonally between perennial refuge habitats and floodplain spawning and feeding habitats.
It is particularly common in areas, where natural floodplain habitats and their connectivity to river habitats are extensive and intact. In the Mekong, the Great Lake and Tonle Sap River floodplain systems are particularly important for the giant snakehead – and this ecosystem consequently harbours the most important fishery, including capture-based aquaculture practices, for this species.
Other areas with maintained river/floodplain ecosystems include several tributary systems in Lao People’s Democratic Republic and Cambodia. In Thailand, the Songkhram River is one of the last tributary systems with maintained floodplain systems – and the giant snakehead is therefore common in both adult and juvenile fisheries.