African tiger scat, Scatophagus tetracanthus
Few freshwater fish have bolder, more striking colouration than the African Tiger Scat, or Scatty, to its friends. Famously brackish fish, the Scatophagus genus are found in estuaries, mangrove swamps and lagoons, where rivers meet the sea, but they can travel up into pure fresh waters as well as far out into full salt, enabling them to colonize coastlines as far apart as East Africa and Indonesia. There are just two valid Scatophagus species, the Spotted Scat, Scatophagus argus, and the Scatty, Scatophagus tetracanthus, featured here. The third species, the Spotbanded Scat, sits within its own genus, Selenotoca, although Selenotoca multifasciata is still very much within the family Scatophagidae.
Scats have a very recognizable look, with deep, almost rectangular bodies. They’re cute as juveniles with the Spotted scat having red coloration on its head and fins and the African tiger those very bold stripes, but all species become more subtly colored, bronzed and metallic when adult and when out at sea. The oceans are where Scats originated from, placing them within the order Acanthuriformes, which includes the saltwater Surgeonfish, Angelfish and Rabbitfish. Scats possess venomous dorsal spines – a feature they share with the Rabbitfishes in the family Siganidae. They graze algae like Surgeonfish and rabbitfish do too, along with detritus and animal fecal matter. Their genus name Scatophagus translates as “dung eater.”
Tank set up for Scats
Although scats may be able to live out their whole lives in freshwater, these are undoubtedly coastal fish that are specially adapted to be able to transition from fresh to brackish and full salt even within the same day, as the tide goes in and out and brings rich pickings with it. Some aquarists may keep the African Tiger Scat in freshwater long term with success, but the fact that they are often found in harbours denotes their preference for salt and the dietary opportunities they present. All three scat species can exceed 30cm/12” in length, and are shoaling species, so they really require a brackish set up of at least 6x2x2’, and they will really fill and utilise all of the tank for swimming.
The term brackish means lots of things to lots of people and sometimes it is even misconstrued as hard freshwater by some. To recreate the kind of brackish waters found in tropical estuaries, mix synthetic sea salt for marine aquariums into freshwater, and use either a hydrometer or a refractometer to mix up a solution with a specific gravity of 1.010 s.g. Seawater has a specific gravity around 1.025, and freshwater registers 1.000, so 1.010 is somewhere in the middle. They could also be kept in full seawater systems. Use synthetic salt for marine tanks as it will also buffer the pH, keeping the water hard and alkaline.
Scats will need powerful filtration from external power filters, and set the temperature to 25 Celsius. Lighting can vary from dim, warm spectrum lighting to LED spotlights, to reef tank lighting. For an authentic look use fine sand or refugium mud substrates, and sugar sized, oolitic aragonite sand will aid buffering. Authentic looking resin mangrove roots are available or try the real thing if the tank is open topped. Failing that any bogwood is fine and some catappa leaves will add to the mangrove swamp look. Live plants won’t survive in that level salt, and the Scats wil eat them. Artificial aquarium plants or overhanging artificial vines (for reptile vivariums,) will add to the coastal jungle look.
Tank mates for Scats
The classic brackish fish species to mix with Scats would be Monos, Monodactylus argenteus and sebae, as well as Archerfish, Toxotes spp. and Shark catfish, Ariopsis spp. Archers can and do spit down insects from above for added novelty factor and there are many brackish species of pufferfish, like Tetraodon nidroviris and biocellatus, although they are prone to taking chunks out of each other and other fish. Mudskippers, Periopthalmus spp. are archetypal brackish fish too, although they spend more time out of water than in it, so any mudskipper set up should reflect that with a suitably large (or even tidal,) land section. Another brackish fish for the fish collector is the Silver Tiger Perch, Datnioides polota, and it would suit a large brackish tank with Scats and Monos well.
Combine Monos, Scats, Archerfish, Shark cats and others and you would need a very large tank longterm, although it can be filtered like a larger tropical tank and will have a tiny fraction of the running costs of a same volume reef tank. Visit a public aquarium for brackish tank/mangrove display inspiration.
What to feed Scats
Scats feed frequently throughout the day in the wild so get creative and try some the gel foods that are available and smear onto wood or rock, as well as offering Nori and lettuce for added herbivorous grazing. Feed a staple diet of flake, sticks and pellets. Frozen bloodworm, mysis, and krill will also be accepted.
The African Tiger Scat is the most striking of the three Scat species, is the least commonly available, as well as the most expensive. That juvenile pattern does dull right down with age and maturity but when in juvenile colouration like our featured fish picture, they are stunning fish for the large, brackish aquarium.
