Both new and experienced pet fish owners often fret about finding a healthy species to introduce to their aquarium. But, how do you even measure the health of one species against the others? And is there really one stand-out species?
There’s probably not a single overall healthiest type of pet fish. That said, in many categories of health and wellness, there are some species that definitely stand out. Let’s break down some of the major health metrics, and see which fish species shines the brightest for each one!
Best Fish for Surviving Different Water Conditions
Survivability in varying tank conditions is a huge criterion for pet fish health. Even tougher and more hardy species often suffer physical symptoms when adjusting to a new aquarium. For sensitive and delicate types of fish, those symptoms can end up being severe or even lethal.
Fortunately, some species can adapt very robustly to an impressive range of water conditions. I’d like to single out guppies in particular here. As a freshwater fish species, guppies already pass a major litmus test for surviving most home aquariums. Saltwater fish, unfortunately, cannot survive in freshwater tanks, which is the type of tank most owners maintain.
Plus, even compared to other freshwater fish species, guppies’ ability to tolerate different water conditions is unusual. Guppies can thrive in a wide spectrum of pH levels, for example, ranging from approximately 6.0 to 9.0.
Likewise, most guppies do fine in a moderate temperature range, between 72°F and 82°F. The species also tends to withstand a generous range of aquarium water hardness, between 8-12 dGH.
Most Nutritionally Flexible Species
On the other hand, simply surviving a tank’s water chemistry is hardly the only marker for a healthy fish species. Another critical factor to examine is nutrition. Finding the ideal diet for any pet fish is usually a protracted and (speaking from personal experience!) painful process of trial and error.
Luckily, some species are much less picky in their dietary needs than others. In this department, I really can’t recommend angelfish highly enough! These guys are omnivores and will eat just about anything, as long as it’s edible. You can opt for standard pellets, flakes, frozen fish treats, or plants. Many owners also prefer to live feed, and that’s a smart and totally viable choice for angelfish.
Though angelfish can survive on most diets, for best results, it’s generally a good idea to mix in some nutritional variety. But, there’s no need to get fancy with it! You can start by trying out a basic alternating schedule of feeding fish flakes one day, plants and frozen meals another, etc. Just enough variation to keep their diet healthy and balanced.
Low-Maintenance Pet Fish
A (admittedly a little boring) detail that I’ve found can easily get overlooked about fish health is the day-to-day maintenance. However, a low-maintenance care routine can actually play a big role in the well-being and overall quality of life of your fish! Less stringent care requirements mean there are fewer areas to neglect, make mistakes, or just plain forget about.
In that vein, the Corydoras (or cory catfish) is one of the most low-maintenance fish species you’ll find. Corydoras fish are bottom feeders, so this means that they’ll achieve most of their diet via scavenging the floor of your tank. That, combined with their friendly and calm disposition, leads to little chance of these fish causing fights or predatory behavior during feeding.
Corydoras are also moderately-sized, so there’s no reason to worry about them crowding a more modest tank. Unless they start breeding, since Corydoras lay groups of eggs. So, it might be best to avoid getting two!
Most Peaceful and Cooperative Fish Species
Besides disease, incompatible water chemistry, and poor nutrition, there is another looming threat for most pet fish species: Other fish. Some species, like betta fish, have a reputation (though not always accurate) for fighting other fish. And, to make matters worse, a few common fish species are actually natural predators of others!
If you’re concerned about preventing fights, nipping behavior, or one of your pets even preying on another, then the harlequin rasbora is an excellent choice. Not only are rasboras colorful and beautiful to look at, but they are also a remarkably sociable and good-natured species. They tend to get along well with all sorts of other types of fish, though they usually do best with other smaller-sized tankmates.
Species that make particularly good companions for harlequin rasboras include neon and cardinal tetras, bettas, and zebrafish.
Fish with the Longest Lifespan
A long lifespan doesn’t necessarily mean a healthy one, but survival is certainly one indicator of health. So, it’s at least worth pointing out the fish species with the longest average lifespan. And, by that count, the common goldfish is at least in the running for the top prize.
Though goldfish often suffer from premature deaths due to unhealthy or improper tank conditions, they are actually one of the freshwater types of fish that live the longest. Many goldfish can swim and thrive for up to 15 years in an optimal aquarium environment. And, if you can believe it, there are confirmed cases of goldfish surviving to 30 years old!
If you want to give your pet goldfish the long and healthy life it deserves, I have a few suggestions for steps to take. Since these are another addition to our omnivorous fish club, it’s best to feed your goldfish a varied diet of pellets, flakes, vegetables, and live food.
You’ll also need to ensure plenty of tank space, as goldfish can get pretty big. Lastly, goldfish like cooler water, so, unless other species in your tank need a heater, you can forgo one entirely.
