Order : Perciformes
Family : SCATOPHAGIDAE
Species : 4 species recognised (as of 2019)
Maximum Length : 35-40 cm (Selenotoca multifasciata)

The Scatophagidae family comprises just four recognised species (of two genera), three of which occur in Southeast Asia. The commonest species in the region is the Spotted Scat Scatophagus argus, featured here: this species may reach up to 38 cm total length, but typically reaches around 20 cm.

Scats are laterally compressed fishes with deep, squarish bodies, patterned with dark spots and stripes against a pale background. The dorsal fin, which often lies flat, has a deep notch which effectively separates it into a forward and a rear fin. The tail fin is truncate, and the anal fin is large and rounded. The eyes are moderately large, and the mouth is small.

The name Scatophagus means 'excrement eating', however this may be a misnomer as their main food source appears to be organic detritus and invertebrates, such as small crustaceans and worms.

These fishes can occur in a range of salinities, from freshwater to fully marine, but are particularly found in brackish, mangrove habitats.

Scats range from east Africa, through the Indian Ocean and Southeast Asia, to the western Pacific Ocean.

Fig 1 : Juvenile Spotted Scat Scatophagus argus in mangrove habitat at Langkawi Island, Peninsular Malaysia.

Fig 2 : Three Scatophagus argus at Langkawi Island, Peninsular Malaysia. The other fish in these images is the Stripe-nosed Halfbeak Zenarchopterus buffonis.

Fig 3 : A lone Spotted Scat swimming just beneath a shoal of Banded Archerfish Toxotes jaculatrix at Sungei Buloh, Singapore.

Fig 4 : A dead, but intact, Spotted Scat, of around 20 cm total length, is washed up on a sandy beach in the north of Singapore.


References :

Fishbase


Thanks to Kelvin Lim for assisting with identification.