Finny Nest-Builders.

Waikato Times, Volume XXIV, Issue 1991, 11 April 1885, Page 2 (Supplement)

Finny Nest-Builders.

SINGULAR Fimi THAT HAVE THE INSTINCTS OK BTUDH. 11 If you want to see a butting match," said a naturalist, " just watoh that aquarium." The latter was a square arrangement, divided in the centre by a glass partition, so " that part held fishes, weeds, crabs, and even a bit of growing coral— all, in fact, being saltwater products; while on the other side of the glass partition were numerous examples of pond and river life, the two being in such close proximity that an excellent opportunity was bad of comparing the individual differ-

ences between the animals of the salt and the fresh water. The individual to which attention had been called was a small, highlycolored fish, about two inches long, that at the approaoh of a finger on the glass rushed at it with every appearance of rage, butting its delicate membranous muzzle against the glass in n manner calculated to demolish its fishy countenance if Kept up. But when the hand was removed the little creature immediately darted back to where a round ball, seemingly of thread*, was suspended to a floating cork, and made so desperate a rush at it, like a boxer striking at a h&z, that it partly disappeared within it, and finally in a few moments the butting resulted in the little creature's making its way completely through the bundle of threads, so that its tail emerged from one end and its head from the other. This being accomplished, it wriggled out and passed repeatedly around the ball, pressing its abdomen to it and then darting off, to return with a small thread or bit of grass to be added to the rest, and again pressing its body to it. It kept steadily at work, only stopping when an intruding turtle came by, when it rushed out fiercely and put the animal to flight. " That," said the owner of the aquarium, "is one of the birds of the sea — a stickleback — and the process you have been watching is the nest building. The ball is the nest, aud you see it is hanging just like those of many of our birds. Some time ago the fish began to collect the material and place it upon the bottom, but as soon as I put the string in the water hanging from the cork, it took possession of that, and by oontinual additions of small bits of thread the nest soon assumed the proportions you see here. The butting ? Well that is the door-making operation, These bits of thread are wound in and out, and once in a while the fish rushes head on to the mass, endeavoring to keep an opening in the interior where the eggs are to be deposited. So a series of butts are kept up until the hole extends entirely through. "How is it held together? Well, the threads are more or less interwound, but when you observed the fish pressing its belly against the nest it was binding the mass round about with invisible cords of a glutinous secretion, taken from a gland that seems provided by nature for the purpose. These are almost invisible to the naked eye. I have dissected the gland, however, and drawn the mucous from it, a clear, colorless fluid that assumes a white thread-like consistency when exposed to the water. Several other fishes have the same provision. When the nest of the stickleback is complete, the male, who has been doing all the work of nest-building, goes off in search «f a female, and drives her into the nest where the eggs are to be deposited, after which she is driven away, the male taking his place in the hole over them, and remaining on guard until the eggs are hatched and the young are able to take care of themselves. This guardship is quite necessary, as other fishes prey upon the eggs, and they need aeration. This is done by the male, who, hovering above them, keeps up a continuous ourrentof water over them, and a more careful or watchful patrol it would be difficult to find. For aquarium purposes, or for young folks especially, the stickleback is a famous fellow, and one of the easiest kept, as well as one of the most intelligent of the fishes." "Is this the only ihh that is a nestbuilder?" the visitor asked. "By no means." wa« tho reyly. " A great many fiah arc nest-builders, and all of them reminds in of the birds. For example, take the Paradise fish of the genus macropas. They are the birds of paradise of the sea, and of most beautiful shape. The tail forms an enormous fan, almost twice as wide as the body proper. The dorsal and ventral fins are also both joined to it and enlarged, their points streaming behind just as do the long, delicate streamers of the bird of paradise, and, aa with them, it is the male that has the most gorgeous decoration. The general color is a rich brown, changing into a grayish green on the under sides, which is crossed and barred by stripes of changeable yellow, green, blue, and red. They are found in Chinese and eastern waters, and they are kept in captivity, as is the goldfish that was also introduced from China. These fishes are easily trained, and can be taken out of the water and placed on the ground for twenty minutes without injuring them in the slightest degree. In their habits they are like the birds of the same name. When a worm ia tossed to them it is often taken and wiped on the sides of the dish or against the plants of the aquarium—in fact, oleaned of dirt before it is oaten." — Philadelphia Enquirer.