One of the most interesting fish is an animal that can inhabit all three watery environments. During certain stages of their lives Scatophagus argus argus can be found in fresh, brackish as well as full strength marine water.  They can be found in The Indian and Pacific Oceans.

The Argusfish or Scat, depending on who you are talking to, lives a complicated lifestyle. The adults live in the open ocean along the shoreline. They spawn in the open ocean and their larvae, called tholichthys, travel into fresh and brackish waters to grow up into maturity. Once they are mature they travel back into the ocean to start the whole life cycle again.

The tholichthys look quite a bit different from their parents. They have large heads and many bony plates. They looked more like marine butterfly fish than Scats. Once they metamorphosize their armor plating changes and they head for the sea. Unfortunately, they have never been bred in the aquarium and considering their complicated lifestyle, probably never will be.

As an adult these fish are certainly marine. They are very hardy, they make a good first fish for the budding marine aquarist. They can tolerate some fluctuations is salinity and other water parameters. They like to be kept on the warm side, from 75-80F. One other thing, they do not tolerate nitrites very well. Make sure that they are housed in an aquarium that has an adequately running biological filter. Maintain the adults in the same water conditions that you would for any other marine fish - Specific Gravity 1.023, Ammonia 0, nitrates below 40 ppm, nitrites 0, and the pH around 8.3.

The adult body shape roughly resembles a hexagon. The upper part of the body is much more arched than the lower. They
have a relatively small head and mouth. They have very small scales. These scales not only cover the whole body, but they also cover the soft rays of the dorsal and anal fins. On the front of the dorsal and anal fins you will find very sharp spines. These spines are used for defense. These sharp spines are separate from soft rays of these fins, they lay flat against the body when not in use.

In the wild these animals reach almost 12 inches in length, but in the aquarium 6 or 7 inches is the more norm. It must be an impressive sight to see hundreds of adults traveling together in a school.


The color of these animals varies from different collection locations and also from different age groups. Overall though, they are found in grayish to greenish tones.

When it comes to feeding these animals, you would soon find out why I called them garbage collectors in the title of this article. In the wild these fish are often found along the coast, feeding on sewage coming in from the rivers.  They will eat anything. They also eat lots of food. Feed them frozen, freeze dried, flake or pelleted foods. They also appreciate fresh meaty foods. One other thing, they love to eat vegetables. Romaine lettuce, spinach, zucchini, peas, and many other green vegetables are taken with great gusto. As a matter of fact, greens are a large and necessary part of these fish's diet, without them Scats will develop possible nutritional deficiencies. Feed them well and often, this will make them very happy.

I have found Scats to be very aggressive with other fishes. I would keep these animals with aggressive species such as
trigger fishes, large angelfishes, large wrasses, etc. Make sure that there are plenty of hiding places for tank mates, as Scats like to chase other fishes.

In the wild Scats travel in schools, however; in the confines of an aquarium there may not be enough room for individuals to maintain the small amount of space that schooling fishes need for themselves. This could result in aggression among the Scats.

I would use as large a tank as possible to house these animals. A 55 gallon aquarium would be just about right for 3 or 4 individuals. I would provide lots of hiding places, such as large clay flowerpots, caves built out of rocks, etc. These animals require excellent mechanical and biological filtration because of their tremendous appetites. I would recommend a large canister or hang on the back power filter for the mechanical filtration. For biological filtration I would use a trickle filter or maybe even one of the new fluidized sand filters. Both of these are capable of processing large amounts of waste. The fluidized sand filter is more compact and may be a better choice.

Again, because of their huge appetites we must do all that we can to maintain excellent water quality. One other way
to do this would be to change water on a regular basis. I would change 25-50% of the water every week or two. This
with proper mechanical and biological filtration will go a long way towards maintaining proper water quality.

While most people want to maintain fancy exotic fishes in their marine aquarium, they sometimes overlook very hardy
and interesting fishes because they may be plain and/or common. The Scat is one of these fishes. They are very
hardy and almost puppy like in behavior. Whenever you approach their aquarium they run up to the front of their
aquarium. Wagging their tails like puppy dogs, wanting to be fed. For a change, instead of buying that fancy angel
fish, why don't you purchase a Scat. You will not be sorry.