DO FISH SLEEP?

Te Awamutu Courier, Volume 72, Issue 6238, 5 June 1946, Page 5

DO FISH SLEEP?

EXPERIMENTS IN LONDON ZOO SOME FISH MORE ACTIVE AT NIGHT “You a-11 know, of course, that fishes have no eyelids. Not being able to close their eyes, do they ever sleep?” That poser was nut the other day by Mr Harry Maurioe, president of the London Zoo, to young listeners in its 8.8. C. magazine programme. Some fish, he told his hearers, are more active by night than by day, and can see where humans could not see at all. As to those which ase fully active by day, whether they fall at night into some state oJinconsciousness which, if it is not sleep, is something very like it, cannot be said for certain. But Mr Maurice thought that some experiments carried out in the zoo acquarium suggest that fish do sleep. The observer went into the acquarium in pitch darkness. Suddenly he flashed a strong- torch into each tank and made a rapid note 1 of what the fishes in it were doing. Some kinds were perfectly still in mid-water, others just below the water surface, and yet others resting with their bodies on the ground. In most cases they were more or less grouped together. With one queer i exception. Mullets, which swim i actively by day, keeping close toIgether, were laying near the bottom of the tank, all separate from one another and all looking in different directions.