THE NATURALIST.

Otago Witness, Issue 2516, 4 June 1902, Page 64

THE NATURALIST.

Fishes Th.it Build Nests.

The cock sparrow takes his bhaxe in building the untidy pile of odds and ends which he and his partner call a nest; but, once the eggs are laid, it is Mrs Sparrow who sits oji them, and performs all domestic duties.

Quite different is the case with the spiny stickleback, which is the most common of British nest-building fish. This brilliant little chap, whose colouis would put a goldfinch to shame, not only builds the family nest entirely unaided, but, after his mate has laid the eggs, he stays and looks after them, and even attends to the young biood when they at lafet make their appearance The stickleback is especially plentiful in the clear, chalk brooks of the South of

England ; and there, wherever weeds line the edges of the stream, may be noticed in (spring his round, compact little nest. It is amazingly well built, considering that its architect has no beak, like a bird, to act as needle and trowel, and that his only

materials are slimy bits of water plants, which he collects and carries to the s>pot in

his mouth. He has, however, one pull over bis neighbours on land. The stickleback has the power of spinning a kind of glutinouo threat!, with which he binds together, ppider-like, his miscellaneous collection of weeckta'ks.

When itll i= ready, and the eggs are hud, he opens the nefct &i that a current / of fresh irater may always pour across the ] und then Lo yjmdia &eatiael ouj£ide. t

Ha never sleeps, and anything that comes near he attacks with such fury that even a pound trout thinks twice of facing this fiend two inches long. When the little sticklebacks are finally hatched, their father's work becomes harder than ever, for enemies swarm around. Curiously enough, the worst enemy of is. their unnatural mother, who would gobble the entire brood if she were allowed half a chance. Perch begin nest-making even earlier than the stickleback. Sometimes, when winter is late and the ice bears into March, it is possible to watch them at work beneath one's feet. They do not actually build like the stickleback, but clear a spot among the weeds, biting off and carrying away every stalk around an area of lOin or 12in, and winnowing the sand with tail and fin, until it is left clear and soft and white. Trout make a hollow for their eggs in the bed of a stream, and salmon create a regular furrow, sometimes as much as 10ft long, in which the eggs are laid and then covered wp with sand and gravel. The salmon uses its tail both in digging and covering its eggs. Dace are wonderful nest-builders. Like rooks, they prefer to remain in the same habitations year after year. They build their nests with stones, of which they make little cairns, as much as Bin high. The stones are quite small, so it takes a large number to do the work. Lampreys have a similar fashion of nest-making, but they show greater intelligence than most other fish. They consider it necessary to use quite large stones to cover the places where their eggs are deposited, and, as one lamprey could not tackle such stones alone, two share the work. What is more, they know enough never to attempt to carry such big stones up stream. They always find them above their nesi location, and, lifting them, allow the current to carry themselves and their burden to the desired spot. As many as 50 lampreys will join together in building a common nest, and some of the stones used will be found to weigh over a pound apiece. Fancy being wrecked upon a fish-nest ! It sounds, absurd ; but this accident actually occurred to a Canadian gentleman who wns canoeing last summer in the Lake of a Thousand Islands, which is a part of the River St. La-wrence. This nest, w r hich was no less than 4ft high, and so solid that it knocked the bottom out of the canoe, was the work of a fresh-water chub — a very similar fish to the common British chub. It was estimated to be 10ft across, and to contain a full ton of stones. It was, of course, the work of a large number of fi&h dxiring successive years. Gobies are well enough known by fishermen around the southern shores of England. Nearly all the gobies build nests of some kind. The best performei in 1 his direction is the black goby, common in the Mediterranean. He seeks the dark depths of submarine tangles of eeaweed, and there, hidden from prying eyes, twists the weedstalks into a sort or circular chamber about a-s large as a small football. In this the eggs are laid. The most skiltul and beautiful of v,ee.-l-builders is a tiny inhabitant of the Gulf of Mexico, called the antennarius. lhe little creature looks for all the world it;el f like a bit of the brilliant yellow weed of which its home is composed. Unlike all other nest-builders, it does not trouble to find a nook near shore, where its nest can be securely anchored, but ties the little globe to any drifting mass of gulf-weed, and so drifts through a happy, sunny existence. In the Saragoesa Sea, where hundreds of square miles of seaweed bind the Atlantic to ar unbroken calm, every square yard has its antennariu& guarding its little home. Its nest very greatly resembles that of our English stickleback, being globular and very compact.

Perhaps the strangest of all material for nest-building is that employed by the para-dise-fish. It is bubbles! The paradise-fish is the famous fighting fish of the Siamese. Though as email as the palm of a man's hand, the atom glows with almost every colour of the rainbow — especially green and scarlet. It is, besides, absolutely fearless, and will follow the finger, if drawn over the surface near its haunts. The Siamese keep the paradise-fish as pets, and match them in battle. When about to build its nest, the paradise-fish rises to the surface and inhales air, then sinks again, and blows the air out in bubbles. These bubbles it has the property of coating with some sticky substance, which, keeps them from bursting. The bubbles cling to a weedstalk, and the eggs are laid among them, and there left to hatch.