The best freshwater aquarium fish are hardy, beautiful, and easy to keep. We’ve picked two of our most beloved freshwater aquarium fish we think you’ll love too.
We plan to eventually build out this page into a hub for freshwater fish species, but in the meantime, we’ve selected two all-time favorites to profile here. We hope you love them as much as we do!
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We’ve also got a deep dive into the wonderful world of goldfish, just for you.
Table Of Contents
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Rummy-Nose Tetra (Hemigrammus rhodostomus)
The rummy-nose tetra is a small, peaceful, and very beautiful fish that likes to live in schools. Its characteristic red spot on the nose only becomes exuberant when the fish is within ideal water parameters and in good health.
There are three species, all very similar, all from Brazil. The “real” Rhodostomus (Hemigrammus rhodostomus), comes from the state of Pará, in the eastern Amazon, and two “false” Rhodostomos (Hemigrammus bleheri and Petitella georgiae), come from the region of Manaus, in the western Amazon.
By “real” we mean that it is exactly the species commonly called rummy-nose tetra.
The differences between the fish are subtle, and show up in the shape and size of the red spot and stripes on the tail. One curious point is that the “real” species is the least colorful, and the most hardy.
Rummy-nose Tetras are not as resistant to bad quality water as other tetras (e.g., neon or cardinals) and can be extremely shy, being less active in the tank. But when they are healthy and confident, they are great fish to have in the community aquarium or even in biotope aquariums (those that mimic the species’ place of origin).
Rummy Nose Tetra Photo by © Mirkorosenau
Species with the typical body appearance of tetras, hydrodynamic and fusiform (in general, fish have a fusiform body, that is, a body that has ends narrower than the center. This hydrodynamic format promotes the reduction of friction with the water, providing better movement in the environment). It has a translucent silver base on its body, but some specimens may show iridescent green scales.
The fins are transparent, except for the tail which is adorned in black and white with horizontal lines, with two horizontal black stripes over each lobe of the tail fin and in the spaces between them white stripes, the total black stripe count being five.
Usually, a black line occupies the central portion of the anal fin. The head is red and iridescent, continuing with the red in the iris of the eye, and part of the red coloration extends beyond the head over the operculum and some scales on the anterior section of the body proper.
The rummy-nose tetra fish reaches a maximum size of 2 inches.
It is a very peaceful species, which can be kept in community aquariums with non-aggressive, similar-sized fish such as other tetras (Cardinal Tetra, Ember Tetra), rasboras (Rasbora Galaxy), Oto Cats, and Corydoras.
You must keep this fish in a school with at least 10 individuals, otherwise, it will be stressed and will present problems such as diseases.
Keep the fish between pH 5.5 to 7.0. It is a soft water fish, so the hardness must be below 8.
As it is from tropical and warm waters, the temperature must be between 75 and 86F.
Diseases & Health
Rummy-nose tetras are very resistant to many diseases. However, any instability in the aquarium (such as rapid fluctuations in temperature or pH) can cause Ich to appear.
They are susceptible to neon disease, a bacterial infection that quickly kills all fish.
Minimum Tank Size
To maintain a shoal of 10 individuals of the species, you need an aquarium with at least 27 gallons (32 x 12 x 16 in).
Elegant Goby (Stiphodon elegans)
The elegant goby is an amazing small fish, perfect for aquariums with strong water flows. Unfortunately, it is still a rather difficult fish to find for sale.
As a peaceful species, it is a great addition to community aquariums. Carefully choose the species to be kept, as they must live in high-oxygen, fast-moving waters. White Cloudy Mountain Minow, Rasbora Kubotai, small danios, and even invertebrates like shrimp make good tank mates.
As much as they show some aggression with other male gobies, as long as the aquarium has dens and decorations they can be kept in a group without problems. Females are peaceful with each other. When keeping these fish in groups, I always recommend using 2 females for each male.
Elegant Goby Photo by © Joan Carles Juarez | Dreamstime
It is a species that should be kept by more experienced aquarists, as they need specific conditions such as water with great oxygenation and free of pollutants. They are extremely sensitive fish to poor water quality, and any sudden fluctuation of parameters will bring problems such as disease and even death of animals.
Their feeding in aquariums can also be problematic.
As it feeds on biofilm (film formed by microorganisms on aquarium surfaces) it should only inhabit well-matured tanks (cycled and mounted for a while). As much as they accept food of vegetable origin (mainly in flakes), the presence of algae and biofilm in the aquarium is essential to stay healthy.
For the well-being of the species, it is essential to provide a mature aquarium with an abundant supply of surfaces such as algae-covered rocks. If you can’t grow enough algae in the main tank, or if you have a community aquarium containing numerous herbivorous fish that quickly consume what’s available, you may need to keep a separate container to grow algae on the rocks and swap them with those in the main tank periodically.
It is a species of difficult reproduction, where the vast majority of the specimens for sale are of natural origin, and its conservation status is starting to become worrying.
These gobies change their colors as they grow. Males can display stronger colors when kept in groups. Males and females have different colors.
The species demonstrates the physical characteristics of whitewater gobies, a long body, and well-developed inferior fins to attach to rocks or substrates.
The upper fins are long and the eyes are well developed, positioned in front of the head.
The elegant goby fish reaches a maximum size of 2 inches in length.
It is a very peaceful species, which can be kept in community aquariums with non-aggressive and similarly sized fish such as small danios and hillstream loaches.
Keep the fish between pH 5.5 to 7.0. It is a fish with fast and well-oxygenated waters, so use a pump 10 to 15 times the water in the aquarium. The hardness must be below 4 to 8.
Despite being a tropical fish, it can inhabit waters with milder temperatures, the temperature must be between 67 and 82 F.
Diseases & Health
When kept in good quality water and within the required parameters, Elegant Gobies are very disease-resistant fish. However, any instability in the aquarium (such as rapid fluctuations in temperature or pH) or degradation of water quality will make the animal suffer.
Minimum Tank Size
To keep a specimen of the species, you need an aquarium with at least 10 gallons. In the case of these gobies, the height of the aquarium does not matter; Anything over 6 inches is valid.
As they are fish that escape easily, the aquarium must be properly covered.
The rummy-nose tetra is a popular freshwater schooling fish, easily identified by the red spot on its nose. It’s important to keep these fish stress-free, to help prevent the contraction of the bacterial infection “neon disease.” They’re peaceful and do great with other tetras and corys.
The elegant goby is a little fish that loves fast-moving waters. They’re a fun fish to keep but are best for experienced aquarists since they require mature tanks (to feed on the biofilm) and careful water monitoring. They can be tough to find in stores but they sure do look neat!