The Best (and Worst) Pet Fish

Fish are Friends

By Max Pedley

In recent years, a trend of “disposable” fish appears to have crept up on us. Advertisements on buying and selling groups stating, “up for swaps”, “free to good home” etc are rising. Frankly, my opinion on the matter is that fish are too cheap. It is just too easy to go out, stock a tank, enjoy it for a week or two before deciding you would like a complete change, barely making a dent on your wallet or morality in the process. So, for those people wanting to break from this vicious cycle of “fish-trading”, what are your options, exactly?

Well, there are actually a lot of large, single specimen animals that might not always command more work but return more on a personal level. These are the fish that are more ‘pet’ than display animal and can make for some really rewarding fish keeping.

Cichlids

Looking back through the ages of fishkeeping, Cichlids have always been traditional “pet-fish”. Early entrants to the hobby included the huge, personable opportunists, the Oscars (Astronotus sp.) as well as the punchy Mbuna of Lake Malawi. Central Americans were not in short supply either, with the prolific Convict Cichlids becoming a household name. These fish are all still popular to this day and with good reason.

Cichlids are amongst the greatest parents of the fish world. Virtually all species care for their eggs and young in some capacity, often in a bi-parental manner. Some species are mouthbrooders, holding both eggs and fry tightly within the mouth, protecting them from the dangers of the outside world. Others are just downright fierce, fending off anything coming too close to comfort and let me tell you from experience, hands sometimes fall into that category!

But cichlids also carry this elevated level of aquatic intellect into other walks of life too. Feeding, for instance, is diverse. Different species develop different mechanisms, with filter-feeders, sand sifters and even grazers being on the list. I believe that this incredible degree of diversity amongst the group has contributed to the success of cichlids in aquaria.

Oscars (Cichlid)

Oscars are misunderstood. Most would have them down as out and out predatory bully boys. This is not the truth. In the wild it has been recorded that Oscars are incredibly inquisitive species which spend most of their time near the surface searching for invertebrates. They will methodically move and pick at leaves, branches and rocks, hoping for their next meal. In fact, the same records state that the Oscars never even make an attempt on smaller fish. Could their aggressive, erratic behaviour in captivity be the result of a lack of enrichment? Possibly so.

We recommend a tank of no smaller than 600litres for a single animal. Bump it up to 750 if you want to keep two. Remember, these are clever fish which need space! Filtration should be strong to compensate for their insatiable appetite and bioload. The pH should be no higher than 7.5 and as with all fish, Ammonia and Nitrite should be 0ppm and Nitrate below 30ppm. Temperature can vary between 24-29c. In terms of feeding, move away from the norm. A diet of gut loaded insects will work well, making sure to mix it up the variety regularly. A formulated cichlid pellet should be incorporated too, to cover any of the nutrients live food might be missing.

Decorate the tank well with large pieces of wood, tunnels, tubes and rocks. Be careful not to include items which the Oscars can pick up and move though, as it is not unheard of for large cichlids to move substrate and enrichment with such force that panes of glass have been split and shattered!

Pufferfish

Of late, a trend towards freshwater pufferfish has been noted. Attributed to social media and beyond, these fish have received their fair share of blissfully ignorant abuse and poor husbandry. All too often, pufferfish, which are by and large quite specialist in both water quality requirements and feeding needs, are crammed into busy, cosmopolitan community tanks and forced to survive, but never thrive. Tiny Pea Puffers (Carinotetraodon travancoricus and imitator) are what you might consider entry level species, whilst the large Tetraodon spp. such as the Mbu and Fahaka puffers are far more demanding in terms of space needed and care afforded.

 Fahaka Puffer

For me, the Fahaka Puffer is the ultimate “pet” pufferfish for the aspiring freshwater keeper. Known scientifically as Tetraodon lineatus, which translates as roughly “Four-Teeth with lines” (This is in reference to the beak which is composed of four fused teeth, and the lined patterns on the body), the Fahaka puffer can on occasion reach a total length of up to 18 inches! An out and out predator, fish close in size will be targeted and often killed by this biting machine. Interestingly, fast, small fish which are perceived neither as a threat nor a meal will go unnoticed by large Puffers.

The species is intelligent, with many keepers stating that their fish even recognise those who are most likely to provide food. Food itself should come in the form of hard bodied shellfish and crustaceans, as well as fish and pelleted food. As with all species, variety is key, and terrestrial invertebrates such as earthworms and roaches can be used too.

Fighting Fish

Probably the smallest of the pet fish, Siamese Fighting fish pose a very realistic option. Small, manageable sizes with lashings of personality bode well. Put bluntly, many Betta are kept incorrectly in captivity. It is of utmost importance that water quality should be maintained to a high standard. Unfortunately, the innate, naturally forgiving physiology of fighting fish means that they can indeed survive in less than adequate conditions, but perhaps this is not thriving. A tank of at least 30l should be aimed for with gentle filtration, a water temperature between 24-30 degrees Celsius and of course, a very tight-fitting lid. As with most surface-dwelling species, these guys can and will jump, when given even half a chance.

Fighting fish might well lack in stature, but they more than make up for it in character. In fact, some keepers train Fighters to swim or even jump through hoops, with the promise of bloodworm as the reward for successful tricks. Don’t expect them to make ideal community tank candidates. Naturally territorial, male and even female domestic Betta splendens have a penchant for protecting their own patch with a great deal of agression. If you have your heart set on tankmates, larger shrimp species, small species of Plecs such as Bristlenose (Ancistrus spp.) and smaller benthic species such as Kuhli Loach (Pangio semicincta et al.) will work best, providing your tank is big enough.

 Snakeheads

Perhaps one of my favourite choices for the keeper of fish with attitude are the Snakeheads. Incredibly poorly misunderstood fish, the genus Channa is a paradox as far as fish go. Snakeheads ignore and actively disregard the rules set down by most fish and their caretakers. They breath air and have no interest in immaculate water conditions. As a matter of fact, water changes would stress some members of the genus out more than dirty water would!

Snakeheads are so called due to the obvious affinity to snakes. Ambush predators too, they are more than happy to hunt other fish, invertebrates, small birds and even mammals. The Giant Snakehead (Channa micropeltes) can grow up to 150cm and weigh nearly 20Kg! This is an animal which is under almost all circumstances, not suitable for captivity and should be left in store tanks when seen on sale. On the other hand, a range of Dwarf species sometimes find their way into the UK trade, including the stunning Rainbow Snakehead (Channa bleheri) of Assam, India.

Rainbow Snakehead

The Rainbow Snakehead tops out at about 16cm and due to its generally sedate lifestyle, a large aquarium is not necessary. Something around 100litres can be considered a minimum, provided the aquarium is wide, as opposed to tall. As pet fish, this can be maintained singularly. The tank should be gently filtered via an air powered sponge filter for best results. In most homes, heating is not necessary for this species. The diet should be comprised of a mix of live, gut loaded insects as well as a proprietary carnivore pellet. Feeding should be carried out a couple of times a week to avoid obesity. Over the winter months, a period of cooling should be carried out whereby the fish enter a state of semi-hibernation. At this time, feeding should be greatly reduced and perhaps even halted all together. Deprived of this cool spell, Rainbow Snakeheads seldom live past a few years of age, before succumbing to organ failure as a result of accelerated metabolism and obesity.

The tank should be well covered to avoid “carpet surfing” but can be well decorated with live plants and plenty of hiding spaces as well as other aquarium décor. These fish may even appreciate a layer of leaf litter under which they can hide.

 Fish to Avoid!

Red Bellied Piranha (Pygocentrus nattereri)

As members of the Tetra family (Characins), Piranhas are highly gregarious, opportunistic feeders, just as happy to survive on a diet of fins and scales as they are feeding on the flesh of fish and other animals. Large growing (Up to 30cm) and very active, Piranhas require a giant tank to thrive. Aim for over 1000l if you really want to succeed. Unfortunately, the low cost of young fish appeals to many who unfortunately make the mistake of keeping this species. Discus Tetras (Brachycalcinus and Poptella spp.) and Silver Dollars (Metynis spp.) make excellent alternatives if it’s the appearance that attracts you. On the other hand, if the behaviour of Piranha whets your appetite, then the more manageably sized Bucktooth Tetra (Exodon paradoxus) might work.

Arowana (Scleropages and Osteoglossum spp.)

All species of Arowana are large fish. The most common in the UK is the Silver Arowana (Osteoglossum bichirrosum) of South America. Regularly reaching lengths of up to 3ft (90cm), a tank with massive base dimension is a necessity. Something like 8ft x 4ft might suffice, if you are aiming for a minimum. Furthermore, Arowana are typically a fish with a close relation to the surface and the immediate area above the waterline Like Fighting Fish, these are air breathers, but also source much of their nutrition from out of the water. Terrestrial invertebrates which may rest on low hanging branches are fair games, as well as anything else foolish enough to come close to the water. This poses problems for the keeper though, as the fish are prone to jumping from the aquarium and in rare cases, injury from impacting the lid of a well-covered aquarium.

Of course, if you have the resources and space to house one of the 5 species of Arowana, they can make excellent pets with lots of character.

Changing attitudes

Hopefully, with more education around the most rewarding pet fish in the hobby, people can make better choices of species which suit them. While there is always a place for display tanks and many keepers are extremely successful with very complex tanks, this is not for everyone. In the same way that some reptiles are better suited to different keepers, fish have very independent husbandry requirements, personalities, pros and cons that set them aside from their morphological appeal.