Fish, Tanks and Ponds

Fish, Tanks and Ponds
A comprehensive guide to fish

Scatophagus argus

Spotted scat

Spotted, scat, Scatophagus, argus
Photos by Andy Rapson


Scatophagus: Greek, skatophagos = feeding upon dung

General Notes:


The spotted scat does best in brackish water, in the wild it can be found in fresh water right through to sea water. If kept in fresh water the water should be hard and alkaline. spotted scats have a forward spine which can inject a painful venom so take care when handling these fish. Spotted scats should be kept in a group in a large aquarium because of their size and activity level with other peaceful fish. Although usually a very peaceful species, large individuals may prey on smaller fish. Most young fish collected for the aquarium trade will have been collected from estuarine water and they should be kept in similar water at home or slowly acclimatised to fresh water. Making a sudden change could lead to high mortality which has been a problem with this species.


Feeds on worms, crustaceans, insects and plant matter by sifting through mud and detritus. In captivity they will accept all food from flake to pellets, live and frozen food, algae, tender aquatic plants. Spotted scats are bold feeders which rarely refuse to eat.


There are no external differences between the sexes.


Spotted scats have never been bred in captivity.

Wild status

The ICUN Redlist of Threatened Species lists the spotted scat as least concern. The fish is very widespread and very adaptable, they are taken as a food fish and they are collected for the aquarium trade but they are of little commercial importance. All spotted scats offered for sale will probably be wild caught.

Information at a glance

pH: 7.5 - 8.4
dGH: 5 - 19
Temperature: 20 - 28°C (68 - 82°F)
Diet: Omnivore
Size: 20cm+ (8in)
Min tank size: 450 litres
Difficulty level: Intermediate
Aquarium type: Community
Swimming level: Middle

Distribution and habitat

distribution map for Spotted, scat, Scatophagus, argus

Origin: Indo-Pacific: Kuwait to Fiji, north to southern Japan, south to New Caledonia, It  has also been widely introduced beyond its natural range

Habitat: Inhabit harbors, natural bays, brackish estuaries and the lower reaches of freshwater streams, frequently occurring among mangroves.


Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Perciformes
Family: Scatophagidae
Genus: Scatophagus
Species: S. argus (Linnaeus, 1766)

Common name:
Spotted scat

Synonyms: Chaetodon argus, Ephippus argus, Scatophagus argus argus, Chaetodon pairatalis, Chaetodon atromaculatus, Scatophagus bougainvillii, Scatophagus ornatus, Scatophagus purpurascens, Scatophagus maculatus, Scatophagus argus ocellata, Scatophagus quadranus, Scatophagus aetatevarians