Fish by size

Nano fish

The atlas's smallest fish: species whose recorded maximum length is 4 cm or less.

1,372 species across 18 families

A fish is listed when its recorded maximum length is 1.6 in or less, as published: standard length (SL, snout to the base of the tail) or total length (TL). An SL figure leaves out the tail fin, so an SL fish looks a little longer in the tank.

Small size alone doesn't make a fish easy to keep or suited to a small tank; each species page carries its own care notes.

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