Target Puffers: Tetraodon barbatus and its relatives
02 November 2007
The pufferfish of the genus Tetraodon are widespread throughout the fresh and brackish waters of Africa, India and Southeast Asia. Although the brackish water species traded as the figure-8 puffer, Tetraodon biocellatus, and the green spotted puffer, Tetraodon fluviatilis and Tetraodon nigroviridis, are commonly seen in aquarium shops, the freshwater Tetraodon are much less frequently seen.
Admittedly, some of these freshwater pufferfish species are of dubious value as aquarium fish. The giant African pufferfish Tetraodon mbu can exceed 60 cm in length and acutely sensitive to nitrate, making it a viable species only in tanks containing several thousand litres of water.
But the smaller freshwater Tetraodon can make excellent aquarium fish, combining attractive colours with reasonable size and overall hardiness. None are good community fish, but being relatively inactive animals much of the time they can at least be kept in fairly modest quarters.
Among these smaller puffers one particular group has proven to do well under aquarium conditions and have become quite popular among fishkeepers looking for something a bit different to the usual oddball catfish or snakehead. There are the target puffers, so-named because of the colourful eyespot on the back half of the body that resembles an archery target.
Tetraodon barbatus, Tetraodon cambodgiensis and Tetraodon leiurus are three of the puffers most commonly referred to as target puffers.
All of these Tetraodon can be maintained in the same basic way. All get to around 15 cm, making them ideal choices for tanks 120-180 litres in size. As with any other pufferfish, water quality is important, so even though there might only be one inactive fish in the tank, scrimping on filtration is not recommended. Use a filter that provides at least four times the volume of the tank in turnover per hour. Generous water changes will help too; certainly not less than 50% per week.
All appreciate moderate temperatures and plenty of oxygen. Aim for a temperature between 24 and 28 degrees Celsius. Tetraodon barbatus is an inhabitant of fast water habitats such as rapids, and as such will not do well without plenty of water movement and a high oxygen concentration. The other target puffers are more adaptable, but cannot tolerate stagnant water conditions.
Whereas water quality is of critical importance when keeping these fish, water chemistry couldn’t be less important. Like most other freshwater puffers these fish are very adaptable. Provided extremes are avoided and the pH stays fairly stable, these fish can be expected to do well in both hard and soft water aquaria. They do not need brackish water.
Unlike the primarily piscivorous pig-nose freshwater puffers such as Tetraodon suvattii, the target puffers are omnivores that feed mostly on molluscs, crustaceans and to a lesser extent on plant material. In the aquarium the ideal diet is based around mussels, squid and unshelled prawns. Smaller specimens will also eat bloodworms and other sorts of insects. Among the live foods that work well with these puffers are pond snails, earthworms and river shrimps.
Never give these puffers feeder fish; apart from the risk of introducing parasites, live fish are not a natural part of their diet and may cause nutritional problems over the long term.
Giving pufferfish their greens is sometimes difficult because we don’t have access to the algae and vegetation they prefer to eat in the wild. Tinned and frozen peas are often taken though, and these also provide a valuable source of dietary fibre. Whole mussels are also very useful for pufferfish because they are usually filled with marine algae. This gives your pufferfish are potent dose of essential vitamins and minerals. This is why experienced aquarists consider whole mussels the “perfect pufferfish food”.
Offering a variety of foods is important for pufferfish just as with any other aquarium fish. Just as with cichlids, it is important not to let these puffers become fixated on one particular food item. If they refuse the food offered on one day, simply remove that food item (to prevent water pollution) and let them starve. A healthy pufferfish can go many days without food. Indeed, some aquarists prefer to feed these fish only every second day. This probably reflects their situation in the wild much more accurately and also helps to keep the water quality good.
None of the target puffers are what might be called sociable community fish! Indeed, most will attack any other fish kept with them. These are definitely one fish per tank animals.
Target puffers are somewhat crepuscular in habits. At least to begin with, these puffers tend to stay hidden most of the time, only becoming active at dawn and dusk. The aquarist should respect this and offer food at appropriate times. Once the fish has settled in, it will become more day-active, and indeed most specimens become positively curious about their environment and will swim about in the open to beg for food.
Identifying target puffers to species level is very difficult, and even the experts have trouble telling them apart. The scientific literature is filled with examples of misidentification, where one species has been referred to as another. As a result of this, the identification of these pufferfish in the aquarium literature is often of questionable reliability. Part of the problem is that Tetraodon leiurus is very variable and some examples of this fish can easily be confused with Tetraodon cambodgiensis or Tetraodon barbatus.
Of the three, Tetraodon barbatus is the most consistent in appearance. The upper surface is yellowy and densely covered with slightly metallic blue-green to steel grey patches and spots. The lower surface off-white and essentially lacks the coloured patches that cover the upper surface, so that the contrast between the upper and lower surfaces of the fish is very striking. The eyespot lies between the dorsal and anal fins and has a red centre and is surrounded by a thin black line and then a thicker yellow circle. As you would expect from a fish that naturally inhabits river rapids, this species has quite a streamlined build with a notably long snout.
Tetraodon cambodgiensis is not dissimilar to Tetraodon barbatus but has a less streamlined build. One peculiarity of the species is that the upper lobe of the tail fin is often, though not always, edged with orange. Some authors consider Tetraodon barbatus and Tetraodon cambodgiensis to be one and the same species.
Tetraodon leiurus is much the most variable of the three target puffers discussed here. Typically the upper surface is brown or grey, blending smoothly with the off-white underside. The patches across the dorsal surface run onto the underside as well. The result is that the contrast between the upper and lower surfaces is weaker with this species than is the case with the other species. The eyespot on the flank typically has a small red centre surrounded by a thick black ring and then a thin yellow ring.
Obtaining target puffers
None of these puffers are commonly traded, though Tetraodon leiurus is perhaps the most widely seen. Tetraodon barbatus perhaps gets the nod in terms of looks, being an attractive, beautifully marked species, but relatively few retailers ever stock this fish. Wildwoods currently have a few in stock, and given their rarity, these are definitely lust-objects for the oddball fish enthusiast!
To find out more about Wildwoods and to view their full stock list click here.
Wildwoods now offer a full mail order service and their fish can be bought through the Tropicalfish2yourdoor service. To buy Tetraodon barbatus click here.