HOW FISH SLEEP

Otago Daily Times, Issue 21668, 11 June 1932, Page 20

HOW FISH SLEEP

THEIR EYES NEVER CLOSE. Do fishes sleep? If yon don’t believe they do; this is the time of the year to learn. For good little fishes in the winter either hibernate, or sleep and rest much more than in the summer. Incidentally, they eat much less, too (writes John Williams, in the Sydney Daily Telegraph). When a fish goes to sleep, he looks quite human. He stretches out on his back, or on his side, or rests on his fins. After a dose in one position, he will wake and roll over. He stretches his fins, as you stretch your arras, and with a.fishy “Ho hum! ” goes off again. ' When he is sound asleep, the breathing decreases remarkably, until the body shows practically no movement. It is not surprising that visitors to the Taronga Zoo Aquarium give the alarm when they see a fish asleep. “Here’s a.fish dead! ” they call. The attendants explain: “ S-s-s-sh! He’s sleeping.-” A fish sleeps more shrewdly than we do. We go to bed, close our eyes, and snore. Once asleep, we are beset by dangers—fire, burglars, murderers.' A fish sleeps with his eyes, open! He is born without eyelids—except in rare instances. Even in the deepest sleep, his eyes are open, and with them he detects oncoming dangers quicker than with hie “hearing” —the sense that - resides in a series of nervous cells which react to sound waves in the water. > You can never “ catch a fish napping.” Try ever ,eo carefully to poke a sleeping one with a stick. Those alert eyes send the alarm to the sleeping body. Instantly it is galvanised into action. A fish knows how to make himself comfortable, too. The “ Maoris ” in the Taronga Aquarium have the best idea. They burrow in the sand, and completely cover themselves. They leave their sandy blankets only about once in every three days for food. During hibernation fish draw on their body-fats for sustenance. For days on end there will not be a sign of life in the Maoris’ tank. To disturb the sleepy chaos you have actually to dig them out of bed with a stick. In the same tank as the Maoris is an Australian crimson-banded parrot-fish. He sleeps standing up on his tail! i There is a corner with a pipe running up it, and his body snugly fits in the corner between the pipe and the wall. Up he springs on his tail, and wedges himself in, much like a mummy in a box. Wake him, and he bolts to the next corner, flings himself on his side, and goes on sleeping. He won’t stay awake. The Lord Howe Island catfish suck up sand like dredges and it some distance away, until holes, like golf bunkers, are dug. Then they curl up in these, and soon are dead to the world. The cod are cute. They don’t bother to dig holes. They find nice holes ready made in the rocks, and jump in. They make sure of being unseen, and so undisturbed, by changing their colours to match the rocks. There is a pink-spotted rock cod called “ Lord Nelson,” because he lost an eye in a fight. Lord Nelson sleeps a lot, and he always does so right against the glass front of the tank. He scrapes a hole in the sand and tucks in. He causes more “ dead ” alarms than any other fish. The fishes become much attached to their particular “beds,” and will not tolerate interference. After a meal they will always return to the same “bed.” Naturally, if one goes to a lot of bother in making an extra special “ bed ” —as many fishes do—a flock of loafers soon float along and want to share it! A cosy “ bed ” is at the root of many aquarium rows. In this regard. Skipper, the grey nurse shark, has matters all his own way. Nobody disputes his possessions. His home is up to date. The overflow of warm water from the tropical section flows into his pool.