Not furry, but we like them anyway.

Spotted Scat

Scatophagus argus

Also called Scat, Green scat, Red scat, Ruby scat, Argusfish

SpeciesShort profile

From Coastal Indo-Pacific, from the Persian Gulf and Kuwait across South and Southeast Asia to southern Japan, New Guinea, eastern Australia, New Caledonia and Fiji1 2

At a glance the quick version

Length20 to 45 cm1 2

Sizelarge

Adaptable to fresh, brackish and sea water across its life

Eats a broad range of foods, plant and animal

Striking spotted pattern and lively schooling behaviour

2 1

Looks how to spot one

Deep, flat-sided, almost square body with a steep forehead

A tall, strongly compressed fish with a squarish outline and a sharply sloping head. Adults are greenish-brown to silvery and dotted with round dark spots, while young fish can show darker blotches or vertical bars. A common size is around 20 cm, with the largest wild fish recorded at about 38 to 45 cm.2 1

Coloursgreen-silver with dark spots (green scat)red-tinted spotted form (ruby or red scat)juveniles with dark bars or blotches2

Personality what they are like

An active, sociable schooling fish that moves around in groups. It is an eager, non-fussy feeder.2

Daily activity how busy a day looks

A busy mid-water swimmer that lives in shoals, so it appreciates open swimming room.2

Grooming and care the hands-on bits

Keep warm, roughly 20 to 28 °C. Young fish come from fresh or slightly salty water, and adults move towards sea water, so salinity is raised gradually as the fish matures. The dorsal fin spines can give a painful prick, so use a net and avoid handling by hand.1 2

Home where they are happiest

Shallow, sheltered coastal water such as estuaries, harbours, mangrove pools and the lower reaches of rivers, at depths down to about 5 m. As it can reach 20 cm or more, it needs a large aquarium with brackish water for juveniles and brackish to marine water for adults.1 2

Food basics what goes in the bowl

An omnivore. Wild fish take worms, crustaceans, insects and plant matter; young ones lean towards zooplankton and adults eat more plant food. Offer a mix of vegetable-based foods and small meaty foods.1 2

Company who they like around

A schooling species that is best kept in a group of its own kind.2

The story where it all began

Linnaeus described the fish in 1766, naming it after Argus, the many-eyed giant of Greek myth, because of its spots. It has long been fished for food across its range and has become a familiar fish in the aquarium hobby.2 1

Fun facts for the dinner table

1
The species name argus refers to the hundred-eyed giant of Greek mythology, a nod to the fish's many spots.2
2
Young scats grow up in fresh water and move into salty water as they mature.2
3
The genus name Scatophagus means 'dung eater', although diet studies have not confirmed that habit.2
4
Females can mature when only 7 to 9 months old.2
5
It comes in two well-known colour forms, the green scat and the ruby or red scat.2

Recognised by the official bits

IUCN Red List: Least Concern (assessed 2009)1
Carl Linnaeus: Described in 1766 as Chaetodon argus2

The care rhythm a typical week and year

A typical home-care rhythm for a Spotted Scat. A starting point, not a vet's advice.

FeedingSmall amounts once or twice a dayevery day
Temperature checkevery day
Salinity checkBrackish fish need a little marine salt, and some need more as they growevery week
Water changeAbout 25% of the water, mixed to the same salinityevery week
Water testevery week
Filter rinseRinse in old tank water, never tap waterevery month

Owner questions the things everyone asks

How often should I feed my Spotted Scat?

Feed your Spotted Scat small amounts once or twice a day. Furry Diary's starting plan is to feed daily, but always check the food label and ask your vet for exact portions.2 Pet Wiki plan

What does a Spotted Scat eat, and what should it never eat?

This omnivore enjoys a mix of vegetable-based foods and small meaty foods like worms or crustaceans. Never feed it anything not meant for fish, and avoid overfeeding; ask your vet for a safe list.1 2

How much space does a Spotted Scat need?

As it can reach 20 cm or more, a large aquarium is needed for this active swimmer. A spacious tank with open swimming room is best, especially for a school.1 2

What temperature, light or water does a Spotted Scat need?

Keep the water warm, roughly 20 to 28 °C. Juveniles need brackish water, and adults move towards marine water, so raise salinity gradually as it matures.1 2

How often should I clean a Spotted Scat's home?

Furry Diary's plan suggests a weekly 25% water change with water mixed to the same salinity, plus a weekly water test. Rinse the filter monthly in old tank water, never tap water. Pet Wiki plan

Can a Spotted Scat live with others?

Yes, it is a schooling species best kept in a group of its own kind. It is active and sociable, so a shoal will thrive together.2

How long does a Spotted Scat live?

Lifespan varies with care, but with proper conditions they can live many years. Ask a good breeder or exotic-pet vet for typical longevity in home aquariums.

Can I handle a Spotted Scat?

Avoid handling by hand, as the dorsal fin spines can give a painful prick. Always use a net to move your fish.1 2

Written from the sources on this page, a few checked guides (VCA, ASPCA, RSPCA) and Pet Wiki's own starting care plan. A friendly guide, not a vet's advice.

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Where this comes from

Every fact on this page has a numbered source. Spotted an error? support@petwiki.app.

FishBase: Scatophagus argus, Spotted scat fishbase.seused for range, size, environment, temperature, habitat, diet, IUCN status, author
Wikipedia: Scatophagus argus en.wikipedia.orgused for names, colour forms, description, salinity by age, diet, naming, fun facts

Checked 2026-09-30. Text is written in our own words from these sources.