ALL ABOUT PUFFER

Inside the mind of a puffer
Author: Neale Monks

Understanding pufferfish behaviour for better pufferfish husbandry

Pufferfish are among the most popular of all the oddball fish, and most aquarium stores carry at least one or two species. There is much about pufferfish that is fascinating, whether it is the fact that many species are highly poisonous through to their bizarre parrot-like beak. Some species do very well in aquaria, learning to recognise their owner and soon learn to beg for food. The figure-8 pufferfish, Tetraodon biocellatus, from South East Asia is perhaps the most commonly seen, but there are plenty of others, including species from Africa and South America. Pufferfish range in size from species over 60 cm when long when mature, like Tetraodon mbu, through to the dwarf species of Carinotetraodon no bigger than a small barb or tetra. Most aquarists are also aware that the puffers sold as freshwater fish sometimes need brackish water conditions to do best, particularly as they mature. The popular green spotted pufferfish, Tetraodon nigroviridis, is one such species, many aquarists having found that the adults will prosper in marine aquaria.

Size and water conditions are two of the key things to consider with any fish, but behaviour is something that is easy to overlook but just as important. Rather than hope that a fish will conform to your expectations as a community fish, puffers need to be worked around, and their rather particular habits anticipated.

The eyes have it
In this article, we’ll try and see the world through the eyes of a pufferfish. In fact, the eyes are a great place to start our considerations. What makes puffers so charming and endearing even to non-aquarists are their large, mobile eyes. Pufferfish hunt almost entirely by sight, and their prey is often slow moving and well camouflaged, things like snails and shrimps. So where another predatory fish might simply wait for something to move and catch its eye, puffers need to explore their habitat carefully, studying the terrain closely to see if something that looks like a bit of rock or algae is in actual fact its prey.

Compared with most other fish, puffers seem to have very expressive faces, and it is this that makes them so popular. In reality, much of this is merely an accident of anatomy. Pufferfish have very large and powerful jaws, and to make room for the muscles that operate their jaws, the nostrils are on the outside of the head, usually just in front of the eyes. Likewise the eyes, rather than being recessed in the head as on most fish, bulge outwards more like those of a frog. They have fleshy lips that normally cover the beak except when the fish is feeding. The lips provide the pufferfish with useful information on the taste and texture of the object it is trying to eat. This helps the puffer decide if the thing is actually worth eating, and makes sure it doesn’t waste energy on something inedible like an empty shell, or worse, accidentally break its teeth or jaws trying to break open something like a stone.

Finding food
All pufferfish are predators, but the way they get their food varies. Three main groups can be recognised: open water hunters, stealth predators, and ambush predators.

The open water hunters cruise over rocky and sandy substrates looking for potential prey. These species feed on things like oysters, clams, snails, shrimps, and crabs. As with all pufferfish, hunting is done by sight, but a particular characteristic of these types of pufferfish is their careful searching behaviour. When looking for food, these puffers will carefully swim up and down objects such as oyster beds, mangrove roots, or aquatic plants searching for potential prey. The hunt is carried out diligently and efficiently thanks to their excellent eyesight and their unique swimming mode. The way pufferfish swim compared with that of other fish is rather like comparing a helicopter to an aeroplane; while they may be slow, they are extremely manoeuvrable, and this allows pufferfish to spot and capture prey that other fish would simply swim straight by.

The majority of pufferfish fall are open water hunters, whether they are marine, brackish, or freshwater species. Like many other open water fish, these puffers are light grey or cream-coloured underneath and green above, making them less easy to see when swimming in open water. Many species also have a scattering of black spots or squiggles on the back and flanks further improves their camouflage by breaking up their outline, in the same way as the stripes on a zebra. Typical examples of this class of pufferfish are the golden puffer, Auriglobus modestus, and the South American puffer, Colomesus asellus. In aquaria, these open water fish need lots of space for swimming as well as a complex tangle of rocks, bogwood, and plants for them to explore.

The stealth predators feed on the same sorts of prey as the open water hunters, but for various reasons prefer not to swim out in the open. The crested puffer, Carinotetraodon lorteti, and the dwarf puffer, such as Carinotetraodon travancoricus, are typical stealth predators. Because they are so small, they are vulnerable to being eaten by larger fish, so they stay close to cover, and are only ever found in overgrown riverbanks and other places where there are lots of tree roots, plants, and other hiding places. An aquarium for these dwarf puffers would need to respect this, and should be thickly planted if you want these fish to settle in quickly. Swimming slowly through the undergrowth, these small puffers hunt for snails, mosquito larvae, water beetles, and other small invertebrates. One peculiarity with these puffers is the strong sexual dimorphism between the males and females. While the females invariably have some type of mottled colouration that provides excellent camouflage, the males are more brightly coloured. The red-tailed redeye puffer, Carinotetraodon irrubesco, for example, is coloured in exactly the way its common name suggests.

The final class of pufferfish is that of the ambush predator. Unlike the other types of pufferfish, which feed principally on invertebrates, these puffers eat fish. However, just like other pufferfish, they lack the speed to chase after their prey, so instead they hide in the sand and then lunge upwards at any fish that swim above them. Fortunately for the aquarist, there is no need to feed this pufferfish with live fish; it will take small frozen fish such as lancefish and whitebait at once, if they’re dangled in front of the pufferfish in a tempting way. Eventually be weaned onto things like prawns, clams, and snails that they will take from off the substrate, something that doesn’t come naturally to these fish given their upwards-pointing mouth. The chief example of this type of puffer is the Congo puffer, Tetraodon miurus. This puffer digs itself into the sand with only its eyes protruding, and then waits for a fish to swim overhead. In aquaria, use a silica or river sand substrate to provide these pufferfish with a soft substrate into which they can dig easily.

Psycho Puffers
Aggressive and territorial fishes, be they puffers or cichlids, are often thought of as simply psychopaths, wanting to do nothing more than spread mayhem and destruction across their immediate environment. While this may be fun to believe, it isn’t good science, and it is far more useful to try and understand why a pufferfish might attack other fishes kept alongside it. The answer is obvious for species like Tetraodon miurus and Auriglobus modestus, puffers that feed either on whole fish or on their scales and fins; but for species that feed only on invertebrates, why would they attack other fish? One thing that can be ruled out is guarding a feeding ground in the way that many damselfish and surgeonfish do. Whereas those marine fish feed on algae that can be “farmed” on a certain patch of rock, the clams and snails puffers prefer cannot be cultivated in any meaningful way because they grow too slowly. At best, a pufferfish can try and monopolise a particular bed of oysters or clams for a while, but eventually if will have eaten all the ones small enough to break open, and it’ll have to move on to another patch of food.

In fact, many pufferfish are territorial for the same reasons as many cichlids. Since the males guard the eggs, they need to be able to clear their territory of and potential predators. Natural selection has favoured those males that drive away predators with the greatest success, since those males have been able to protect the most eggs, and so have passed on their genes most effectively. Males also need to hold their territories against rival males even before he has eggs to look after, since the best nesting sites are often in short supply. This works to advantage of the female when it comes to choosing a mate with the best genes: if she can find a male that can successfully defend his territory against his rivals, she can be sure that he has good genes. Simply being aggressive all the time is counter-productive though. There’s no evolutionary advantage to picking fights outside of the breeding season if there’s nothing worth fighting for. Hence, pufferfish that fight to protect their eggs or nesting sites do so most vigorously only at certain times of the year.

Among the species that are only aggressive when breeding are several species of the dwarf puffer genus, Carinotetraodon. They are otherwise tolerant of one another most of the time and it is possible to keep these fish in groups. The key thing is not to overcrowd these fish; even though the are not looking for fights, if they are forced to live check-by-jowl, flare-ups will happen. Small species like Carinotetraodon travancoricus can be kept in groups with around five gallons or so allotted to each fish, and a pair of Carinotetraodon irrubesco will get along perfectly well in a ten- to twenty gallon aquarium. As well as tolerating conspecifics, these little puffers usually get along well with small, slow-moving, non-threatening tankmates such as Otocinclus catfish and gobies. Making sure there are lots of places to hide is important, not only for the pufferfish, but also for the tankmates. Any territoriality from these pufferfish is usually short-lived, and so if the other fish can get out of the line of sight, things normally settle back down again very quickly.

The figure-8 puffer, Tetraodon biocellatus, is another species that can be kept in groups, though being rather larger than Carinotetraodon species the aquarist does need to provide a bit more space, something around 10 to 15 gallons per fish being about right. Other species that cohabit peacefully with their own kind include Colomesus asellus, Tetraodon fluviatilis, and Tetraodon nigroviridis, though with the last two species especially account does need to be made for their relatively large adult size. It would be unwise to keep more than one specimen in an aquarium of less than 55 gallons.

There are some puffers though that hold such large territories, and seem to do so even when not spawning, that keeping them in groups is practically impossible in home aquaria. Tetraodon lineatus (commonly referred to in the hobby as Tetraodon fahaka) is a famous example of this, and it simply cannot be kept in an aquarium with any other fish. Indeed, it will even attack the arm of any aquarist foolish enough to work in the aquarium without first pinning the pufferfish back with a net. Other pufferfish that cannot be kept in groups include all the traded species of Auriglobus and Chonerhinos, Tetraodon miurus, and the brackish to marine species Arothron hispidus.

Of fin nipping and boredom
Some pufferfish are known to be semi-parasitic, that is, supplementing their regular diet of snails and shrimps they will also eat the scales and fins of larger fish. This behaviour, also observed in many barbs and tetras as well, can be very troublesome for the aquarist. Among the species known to be persistent fin-nippers are the milk-spotted puffer, Chelonodon patoca, and all the traded species of Auriglobus and Chonerhinos.

On the other hand, the majority of puffers seem to be opportunistic fin-nippers, and do so only under certain circumstances. The South American pufferfish, Colomesus asellus, for example, only seems to go for slow moving species such as Corydoras, fancy livebearers, and gobies. Provided it is kept with more active fish such as tetras, halfbeaks, and hatchetfish, it is entirely trustworthy. Remember the sensitive lips mentioned earlier on in this article? For a hungry pufferfish, the way to see if something is edible is to have a bit of a nibble. Obviously nibbling on a rock does no harm, but if the pufferfish is trying out a bit of Corydoras, then the results aren’t so good.

As mentioned earlier on, most puffers have evolved to explore complex environments while searching for food. Whether it is this that makes them so intelligent is an interesting point for debate, but certainly pufferfish kept in empty or thinly decorated aquaria show all the classic signs of boredom: listlessness, destructive behaviour, and seemingly random aggression. Pufferfish need to be stimulated, and providing them with an aquarium that demands exploration will do this. Use lots of rocks, wood, and plants to create an aquarium that isn’t an empty box but one filled with caves and structures. You will then be able to watch your pufferfish behaving naturally, searching every inch of its surroundings for potential prey. Floating plants are particularly valuable in aquarium containing the open water species, providing them with interesting places to explore not just at the bottom of the tank but at the top as well. Most puffers seem to enjoy sandy substrates, either completely burying themselves under the sand or at least rooting about in it looking for snails. In short, the more in the aquarium for the pufferfish to “play” with, the less likely it is to develop any bad habits.

Pufferfish are not the thugs of popular legend, but fish with very specific needs that too many aquarists fail to consider. While it is probably true that none are perfect community fish like neon tetras or Corydoras catfish, only a relatively small number are so aggressive that they have to be kept singly. They are intelligent and need constant stimulation, and whether that is by creating a complex habitat or providing suitable tankmates, keeping pufferfish properly is a challenge, but one that is ultimately very rewarding.

First Published Practical Fishkeeping Magazine, August 2006

Alone but Not Lonely: The Importance of Keeping Puffers Solo
Author: Damien Wagaman, AKA puffer_archer

Lately, I’ve been concerned about a trend I’ve noticed on Puffer-keeping forums: Aquarists purchase an additional Puffer to prevent the first Puffer that they own from “getting lonely”. In this article, I hope to explain why this is unnecessary, and may even be hazardous for your Puffers.

Many fish species throughout the world school or shoal for protection from predators. By staying together in large numbers, these fish are able to reduce the chances of becoming a meal. Sometimes, young Puffers are found in large groups. However, as they mature these Puffers usually go their separate ways. From this point on, Puffers begin to live a solitary life where interaction with conspecifics is usually limited to mating season and the occasional territorial dispute. There is a very logical reason for this — Puffers are predators! As predators, they spend many hours cruising their territory searching for food. It may be many hours between meals, and if they find an area that is rich with food, they are not going to want another Puffer eating what could be their last meal for days. This is why Puffers declare territory as their own and will occasionally fight to the death to defend it.

In the aquarium, territory is at a premium. Compared to the rivers, estuaries and open oceans that puffers inhabit in the wild, the aquarium is a very small environment. As a territorial family, Puffers require space to call their own. Introducing more than one Puffer into a tank, especially a tank that is too small, is asking for problems. If two Puffers cannot establish clear territories, they will often fight. Depending on species, some will not stop until they kill the other Puffer. After purchasing several puffers, many people will talk about how well the Puffers get along and seem to be best friends. Unfortunately, most newly-purchased Puffers are still very young — probably under a year old. This means they are still immature and focused on surviving into adulthood more than anything else. As they age and mature these “buddies” often start to define territories and if enough space is not provided, they will start to fight over the given space. With some species, such as Tetraodon lineatus, this fighting usually leads to one badly injured Puffer and another dead Puffer. So, as solitary fish that need space, Puffers do not need tankmates.

Perhaps some other fish can live with the Puffer? Well, this really depends on the Puffer species. When it comes to piscivorious Puffers (those whose primary diet is fish), cohabitation with another fish is a death sentence. These Puffers will ambush and kill any tankmates, even those who are much larger than the Puffers themselves! The molluscivores (Puffers who primarily eat crustaceans) may accept tankmates. Some may accept them for life. Others will tolerate tankmates for a while, then one day decide that they want to see how they taste! So, while some Puffers may tolerate other fish, it is best for them to either be kept alone or in a species tank.

Anyone who has kept a Puffer knows that they are not the fastest swimmers in the world. They float around more like a blimp than a torpedo. What does this have to do with keeping them with tankmates? It presents a problem during feeding time. Fish that move much faster than Puffers are often able to consume the majority of the food before Puffers are able to get their share. This is especially true for some of the smaller Puffers, such as C. travancoricus (Dwarf Puffers). To compensate for this inequality in feeding, owners will often overfeed the fish in order to allow the Puffers to get enough to eat. The result is an excessive nutrient load in the aquarium from leftover food rotting in the tank. This situation can lead to algae problems, or even a crash of the tank, and could kill the inhabitants.

It is a common thing for Puffer keepers to give the animals human characteristics. Unlike people, Puffers do not need friends or companions for their well-being. They will not get lonely nor will they become depressed because they do not have another Puffer around. In many cases, quite the opposite is true, and they can be much more personable to their keeper if kept as individuals. As a general rule, most Puffers will live a healthier, happier, less stressful life if there are no other Puffers in their territory.

As with any rule, however, there are always exceptions, and this one has a few. While most species of Puffers do best alone, there are a few that will tolerate tankmates. These exceptions do come with a disclaimer: “Puffers, as a species, are individualistic - and while one Puffer may get along with tankmates, a different Puffer of the same species could be completely intolerant of anything else in their tank.” For this reason, if you decide to keep multiple Puffers in the same tank, you should have an alternative tank available just in case things don’t work out.

The first exception is the popular Dwarf Puffer (Carinotetraodon travancoricus). This Puffer stays small, only reaching 1-1.5 inches. One thing that makes these Puffers unique is that it is easy to determine their gender once they have sexually matured. The males stay smaller and develop a dark brown vertical stripe on their stomachs. Females are usually larger and lack the stripe (Ed note: Males can always be distinguished by their colourful cheek “wrinkle” patterns). If the proper tank is provided (that is, one that supplies at least 2-3 gallons per Puffer), is heavily decorated and has more hideouts than there are Puffers, then keeping 2 or 3 females to one male often works well. In fact, under these circumstances and with proper diet, Dwarf Puffers will often spawn. Dwarf Puffers have been kept successfully with Otocinclus algae eaters. There has also been limited success in keeping Dwarf Puffers with different species of shrimps, such as Amano, Cherry or Ghost shrimp. There is always a risk with shrimp that some Dwarf Puffers will decide that they are food and will eat them.

Another freshwater Puffer that has been kept with conspecifics successfully is the South American Puffer (Colomesus asellus). In large tanks, at least 55 gallons, South American Puffers can be kept in small groups. As with any Puffer, the tank needs to be heavily decorated. The decorations should be set up so that they break up the sight lines in the tank to minimize confrontations. Also, there should be more caves or hiding spots than Puffers in the tank, to prevent them from fighting over a place to sleep or rest.

Tetraodon biocellatus or the Figure Eight Puffer, tends to live longest when kept as an individual. A study done on keeping Figure Eights demonstrated that individuals live much longer than those housed together. The oldest individual in the study lived for more than 18 years! However, they have been kept with Bumblebee Gobies (Brachygobius nunas). These Gobies stay very small and generally keep to themselves. They are also excellent scavengers and do a good job of cleaning up the mess that the Puffers often create when eating. Figure Eight Puffers and Bumblebee Gobies are a good mix because they have very similar environmental requirements. Both will do best in lightly brackish water with a specific gravity around 1.005. It must be noted that occasionally, especially in a tank that is under-decorated, Figure Eights will decide to taste their Goby tankmates.

The Green-Spotted Puffer (Tetraodon nigroviridis) and the Ceylon Puffer (Tetraodon fluviatilis) are other exceptions. When given the proper environment, these two species will often cohabitate without a problem. Often, multiples of the two species can be kept together as well. As a reminder, for this to work well, the tank must be well decorated, with plenty of hiding places and lots of space. For these larger Puffers, they need at least 30 gallons per Puffer. If kept in anything smaller, there is a much greater risk of fighting and territorial issues.

There are several things to consider when keeping multiple Puffers of the above species in the same tank. First, always add Puffers of the youngest age and smallest possible equal size. Young Puffers tolerate each other better and are more likely to get along throughout their lives. Second, always add them at the same time. Adding a new Puffer to an established Puffer tank is a sure way to get the Puffers to fight, and possibly kill each other. If the need should ever arise to add a Puffer to an established tank, the best way to do it is to remove the established puffer, redecorate the entire tank and then reintroduce both Puffers. Unfortunately, even this may not be enough. For this reason and simply because Puffers are so unpredictable, alternative housing arrangements should always be available.

While all of these Puffers have been kept together with either conspecifics or other fish, it is always a risk. These fish are, first and foremost, predators — and that instinct will never go away. Always have a spare tank ready to go in case things begin to go bad. Minor disputes between new tankmates are completely normal as they set up territory and adjust to the captive environment. Should the fighting continue for a prolonged time or become worse, the Puffers should immediately be separated to prevent any permanent damage or death.

I hope that this article helps to dispel a few of the common misconceptions present in the hobby regarding Puffers’ social habits. Please feel free to PM me if you have any further questions on this topic.

Resources:

Ricketts, Robert T. Figure Eight Puffers: A Great Small Brackish Fish.

ni ikan bukannya salt water yah? salam kenal semua...

banyak jenis nya bro, ada yg tawar, payau, maupun laut....