Scientific name: Hyphessobrycon pulchripinnis
Common name: Lemon tetra
Max. size: 3.8 cm / 1.5 inches
pH range: 5.5 – 8.0
dH range: 25
Temperature range: 23 – 28°C / 73.5 – 82.5°F
The Lemon tetra is a popular aquarium fish, but more difficult to breed in captivity compared to its famous relative the Neon tetra. The Lemon tetra is endemic to a river in Brazil and can be found nowhere else in the world. The Lemon tetra is a peaceful fish and will work well in a peaceful community aquarium with other species of similar size. The aquarium should be planted, the water should be slightly acidic and the water hardiness should be soft to medium. Since the wild Lemon tetras inhabit a tropical river, the water temperature in the aquarium should not be allowed to drop below 23° C (73.5° F). The Lemon tetras have a quite pale, yellowish colouration that will look more striking if you use a dark substrate in the aquarium.
The Lemon tetra is and benthopelagic freshwater species endemic to the Tapajós River basin. The Tapajós River runs through a hot and humid part of Brazil before it empties into the famous Amazon River about 500 miles above Pará. The Tapajós River is roughly 1200 miles long. This habitat is tropical and the water temperature stays between 23 and 28° C (73.5 – 82.5° F).
The largest scientifically measured male Lemon tetra was 3.8 centimetres (1.5 inches) long, while the largest female was 3.6 centimetres (1.4 inches). A lot of aquarists have however kept larger specimens, up to at least 6 centimetres (2.4 inches). The max published weight is 1.4 grams for males and 1.2 grams for females.
The body of the Lemon tetra looks like most other members of the genus Hyphessorbrycon – compressed and medium tall. The body is translucent with a slight yellowish tinge and you can see a shimmering lateral stripe that runs from the gill cover to the beginning of the caudal fin. The front fins feature a bright yellow coloration while the end and edge of the dorsal fin, as well as the back rays on the anal fin, are black. The upper part of the eyes has a characteristic strong red colour.
Always get at least five Lemon tetras, preferably more, since Lemon tetras that are kept in too small groups will become shy and stressed. A large group of Lemon tetras is much more entertaining since they will boldly swim around in the middle and top part of the water column. A small group of Lemon tetras (or even worse – a single Lemon tetra) will typically spend its time hiding or sitting at the bottom. The stress from being alone will also make the fish more prone to illness. The recommended minimum aquarium size is 60 centimetres (24 inches). You can house the Lemon tetras with other peaceful fish species of similar size, provided of course that they like the same water temperature and chemistry as the Lemon tetras.
Try to mimic the natural Lemon tetra habitat when you set up your aquarium. A densely planted aquarium with at least one large area open for swimming will be greatly appreciated by your Lemon tetras. If you want to make the Lemon tetras look more colourful, you can use a dark substrate in the aquarium since the contrast effect will enhance the fish colouration.
The water in the aquarium should be clear and regular water changes are of course necessary to keep the water quality up. Lemon tetras can adapt to a pH from 5.5 to 8.0, but acidic water is recommended. Keeping the pH around 6.0 is ideal. The water should be soft to medium hard and the dH should not exceed 25. Since the Lemon tetra is native to a tropical river, the water temperature in the aquarium should be kept between 23 and 28° C (73.5 – 82.5° F).
The wild Lemon tetras are omnivore and will of instance eat plant matter, worms and crustaceans. Keeping your Lemon tetras on a varied diet is recommended. They are usually happy eaters in captivity and will accept a wide range of food types. You can use a high quality tropical flake as a convenient base, and add treats in the form of live, freeze-dried or frozen meaty foods like worms. Lemon tetras will also like boiled vegetables, e.g. zucchini.
The wild Lemon tetra is a prolific species with a minimum population doubling time below 15 months. The Lemon tetra can however be tricky to breed in captivity, especially compared to its more productive relatives like the Neon tetra. Professional Lemon tetra breeders will usually combine several females with one male to increase the chance of success, since female Lemon tetras sometimes have trouble releasing their eggs.
During the spawning, the female Lemon tetra will release her eggs among fine leafed plants. Including such plant species in the aquarium set up is therefore very important if you want to breed Lemon tetras. The fertilized eggs will hatch after approximately 24 hours. The fry is very sensitive during the first few days, but if you manage to keep them alive during this critical period they will usually become very hard and a lot of them will reach adulthood (if they are kept in an aquarium without predators). Since the Lemon tetra is an egg-scattering species that do not engage in any form of parental care, the adult fish will not hesitate to eat their own eggs and fry. If you want to ensure a high fry survival, you must therefore set up a separate breeding aquarium from which the parent fish can be removed, or let them spawn in a densely planted aquarium with fine leafed plants that will provide the Lemon tetra fry with a lot of good hiding spots. Even in a densely planted aquarium, a lot of eggs and fry will however be eaten.