Which shoaling fish should we choose?


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Bob helps a reader who would like to stock their tank with some shoaling fish...

Q) After keeping fish for three years, we're about to set up our first 'big' tank which is approximately 120 x 45 x 45cm in size. We'd like to have three or four types of fish including a large shoal of a small fish species such as Neons or Rummy-noses. Any ideas as to the best species to choose for this would be great. We also want some corys, a couple of 'feature fish' for the top — maybe Pearl gouramis — and perhaps also a bristlenose or a Clown plec.

The tank is planted with Hygrophila, crypts and Java fern which is all settling in, and we’ve added some wood — but no fish as yet until it’s all properly matured. Any thoughts on this set-up would be welcome.


A) Bob says: Setting up a new tank is always an exciting prospect and looking into possible stocking choices is one of the most exciting elements. Your new tank is a lovely size to make an impressive display in and I applaud your plan to stock it with larger groups of small fish species rather than just one or two 'big' fish.

Most fish only shoal tightly for protection, so once settled into an aquarium and feeling safe, they tend to spread out around the tank rather than hold tight formation together. Rummy-noses are fairly reliable at sticking reasonably close to each other but don't expect 'Red Arrows' type synchrony! Another possible choice is the Harlequin rasbora — a reliable old favourite which is under-rated in my eyes. Adding a group of 10 of either of these would make a great start.

You mention Corydoras, and again these are a fantastic, peaceful choice with plenty of attractive species to choose from. Substrate selection is important with as coarse gravels can cause damage to their sensitive mouths. They should be kept in groups of a minimum of five of one species, but the more the merrier.

Pearl gourami are also beautiful fish, especially the males, but I'd recommend adding three of these: two females and a male, to help prevent the male harassing a lone female endlessly. Otherwise, a single male is probably your best bet. A good shop should be able to sex them for you unless the fish are tiny.

A bristlenose catfish would be be a characterful and hardy choice and they are generally more likely to be seen out and about in the tank than Clown plecs, which can be very secretive.

Did you know? 

There are actually three similar species of tetra in the hobby sold under the Rummy-nose name. The ‘true’ Rummy-nose is Petitella rhodostomus, but most of those seen in the shops are P. bleheri, sometimes also referred to as the Firehead tetra. A third fish, Petitella georgiae, is known as the False rummy-nose. They all grow to around 5cm/2in in size, with females being slightly larger and deeper bodied than the males. Soft, pH-neutral or acidic water, and a temperature of 25-26°C will suit all three species.