Order : Siluriformes
Family : CLARIIDAE
Species : Clarias batrachus
Maximum Length : 47 cm

The Common Walking Catfish is an adaptable species able to survive in disturbed, stagnant or somewhat polluted waterbodies such as rural streams, rice paddies, concrete drainage channels or man-made ponds, lakes and swamps. During flooded or rainy conditions this species can move from one water body to another overland.

Adults can reach up to 47 cm in length, though most fully grown specimens are around 30 cm or so. Its body colour is greyish or pale brown, and its head is reddish brown. There are narrow bands of pale spots on the flanks, though these are often faint.

It possesses four pairs of long barbels, which are sensory devices used to locate food prey, which comprises other fish, aquatic invertebrates such as shrimps or insect larvae, and aquatic plants. The barbels also allow this nocturnal species to navigate amongst sunken debris at night. By day it lies concealed in muddy substrate or beneath fallen leaves, logs or other debris.

It can be distinguished from the similar Forest Walking Catfish Clarius leiacanthus by only having a narrow gap between the leading edge of the long dorsal fin and the trailing edge of the bony plates on top of the head. In addition, the head is more oval and rounded than that of the Forest Walking Catfish, which is more squarish in outline.

Clarias batrachus occurs in many parts of Southeast Asia, and has been introduced outside its native range. In Singapore, this native species has been displaced in many waterways by Clarias gariepinus, an introduced catfish originally from Africa (Tan et al, 2020).

Figs 1 to 3 : Common Walking Catfish from shallow, rural stream with sandy substrate and accumulations of  rotting leaf litter.

All photos taken in Singapore.


References : H10

Tan Heok Hui, Kelvin Lim Kok Peng, Liew Jia Huan, Low Bi Wei, Rayson Lim Bock Hing, Jeffrey Kwik Teik Beng & Darren C. J. Yeo (2020). The non-native freshwater fishes of Singapore: an annotated compilation. Raffles Bulletin of Zoology, 68: 150-195.