How fast are larval fishes?

Contrary to a previously held notion that larval (baby) fishes are at the mercy of ocean currents, many larval reef fishes are in fact very strong swimmers and can swim surprisingly fast.

Larval Pinstripe Butterflyfish

Colin Wen © Colin Wen

The average 1cm long fish larva swims at 20 cm/sec (14 body lengths/sec).  To put these figures into perspective, if Olympic swimmers could swim as well as fish larvae, they could do the 100 m in 3.6 seconds. The world record is about 48 seconds.

Reef-fish larvae also have amazing endurance. The average reef-fish can swim in a laboratory tread-mill, without rest or food, for several days covering about 40 km. Scaled to size, this is equivalent to a human swimming about 4000km.

Further reading

  1. View information on Dr Jeff Leis' research on larval fishes.


Mark McGrouther , Collection Manager, Ichthyology
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Tags fishes, ichthyology, larval, swimming, speed, fast,