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Discover the 3 best shoaling fish for your Aquarium!

Imagine a brightly lit aquarium, lined with platoons of  luminous green plants proudly guarding  a centerpiece of algae and moss-clad bogwood.

Around it, small shoals of Corydoras catfish zip across the sand, Elegant cichlids, intricately marked, pick their way through groupings of plants while tiny ottos hang on to the broad upright leaves, delicately polishing the algae away.

To many fishkeepers, this may seem like the dream aquarium – a South American community that comes straight out of a brochure. Simple, effective, and colourful.

However, the intricately placed plants and sand in your mind’s eye might include something extra, not present in the description above.

Throughout our imaginary tank, a certain level of activity is missing. Got it yet? Yes; a group of shoaling fish. Classically placed in most community aquariums and perfect for adding color and activity.  Life without a large shoaling group tend to look  barren and devoid of movement.

Yet as with your choices of fish, picking shoaling fish should not simply be any port in a storm.

Instead trepidation and consideration should be considered paramount to cultivating a happy and healthy community.

Firstly, it is always best to opt for a larger group of the same species rather than small bundles of different fish. Although you may be attempting to add diversity and colour, the results are often chaotic, devoid of vision and harmful to the fish.

By their very nature, shoaling fish are social animals.

Ultimately this means that by keeping them in larger groups they will tend to exhibit more natural behaviours and show their colouration (due to their higher levels of confidence in larger groups). Larger groups of the same fish also offer a  more natural feel to the overall look.

Discover below, our top three shoaling fish, that might just be perfect for your next aquarium project…



  • The Rummy Nose Tetra.

The silvery flanks of the rummy nose tetra only serve to emphasize and draw attention to its fire-red beacon of a head and its striped tail. One of the most popular shoaling fish, this species has soared in numbers due to its use in some of the most renowned and acclaimed aquascapes. It is chosen for its tight schooling behaviour. Most tetras begin to spread apart and relax once they settle into an aquarium, grouping together only when danger is present. However, this fish often sticks together regardless of circumstances. The rummy nose tetra is a common feature on most stocklists. It would be a rare occurrence if you struggled to find a shoal of this species.

  • Minimum number: 10
  • Minimum tank size: 24” x 15” x 15” (60cm x 37.5cm x 37.5cm)
  • Average individual size: 2” (5cm – 50mm)
  • Origin: Venezuela and Brazil

  • The Harlequin Rasbora.

Small and stout, the harlequin is a spectacle of energy and grace, a rare juxtaposition that can be understood only after watching them interact as a group for several hours. Copper coloured with a purple sheen, this species has unusual colours that help it stand out from the crowd and allow it to complement aquascapes. However, although they  stand proud from the flora they arn’t  too brash and unnatural-looking. The harlequin rasbora is best in large groups. In sufficient numbers, males will compete for female attention and rivalries will play out, boosting the colours of the males.

  • Minimum number: 8
  • Minimum tank size: 24” x 12” x 12” (60cm x 30cm x 30cm)
  • Average individual size: 5” (4 cm – 40mm)
  • Origin: South East Asia



  • The Lemon Tetra.

Dazzling simplicity and snow-white edging make this tetra, a magnificent addition to any aquarium. Individually, their striking red eyes complement their lemon-hued bodies while their white-capped fins create a sense of distinction. However, as a group, they don’t have just some of the qualities required in a shoaling fish; they have them all. This species is a real shoaler. Regardless of circumstances, tends to stay together, often due to its competitive behaviour, with males sparring for female attention – a source of constant activity amongst them. They also seem to have struck that stardust-like quality of being simple enough to avoid overshadowing any other species or the overall aquascape while still being beautiful enough to captivate viewers for hours. Though they are often seen for sale as drab juveniles, patience has its rewards; as specimens age, their colour tends to improve.

  • Minimum number: 8
  • Minimum tank size: 24” x 12” x 12” (60cm x 30cm x 30cm)
  • Average individual size: 2” (5 cm – 50mm)
  • Origin: South America

Alexander S. Howson

Alexander S. Howson is a naturalist and nature writer.

Along with a heavy interest in Aquatics, birds and ecology. Alexander now directs a large deal of energy attempting to re-educate the public about aquatics and promoting the conservation of a range of wildlife species.

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