TROUT HATCHERIES.

Taranaki Daily News, 20 August 1921, Page 12

TROUT HATCHERIES.

IN PUKEKURA PARK.

TARANAKI AOCLIMATISATION . SOCIETY’S WORK.

These hatcheries are now in full swing, and have 'been largely patronised by the public of late, who have been full of appreciation of the work of the society, and in particular of that of Mr. W. J. Bell, who is superintending operations. Indeed, one visitor from the South Island remarked that it was well worth travelling to New Plymouth to see j the hatchery alone. There are now some 275,000 ova and young trout on view, but would-be visitors are urged not to delay if they wish to see them, as they are progressing so rapidly that the commencement of liberations takes place at once. Briefly, the series of operations now going forward is as follows:—The ova arrive packed in butter-cloth, resting upon moss; the case in which they travel is also arranged to carry a quantity of ice. This keeps the vitality of the eggs down, so that, being semi-dor-mant, they are less likely to sustain injury on their journey. Even then the boxes of ova have to be handled with extreme care. For instance, a heavy blow to the case is sufficient to kill a large number of eggs Arrived at the hatchery, the ova are carefully unpacked, or floated off the butter-cloth into a bowl of ice-cold water, and then spread on the hatching trays The troughs which contain these also contain at first large pieces of ice This gradually melts, and the water rises to its normal temperature without injuring the ova, which otherwise would be killed by the shock. The trays are placed in tiers in the troughs, and by an ingenious arrangement the water is made to rise through

them all from bottom to top in succession. On examining the eggs, it will be noticed that there arc two black dots, some way apart, in each of them. These are the eggs of'the future fish, and when they are present it is certain that the egg is fertile. When -nearing hatching, it is possible to see the eyes moving about in the egg, through the semitransparent shell, giving it a somewhat uncanny appearance. In a few days, depending upon how far advanced the ova were when received, and upon the temperature of the water, the young trout commence to burst their shells and tomake their appearance. They do. not look' very much like fish, for each troutlet has attached to its abdomen a sac, or, rather, one might say, each sac v has a troutlet attached to it. This is /the remainder of the yolk of the egg, and the fish gradually absorb it, growing fast all the time. When it is just absorbed is the time to plant the fish in the rivers. There are many queer freaks of Nature among the baby fish. Some have two heads, some two tails, and some are Siamese twins. These, of course, live only a very short time. In liberating the' fish the greatest care has to be exercised in bringing the temperature of the water in the fi«sh cans to that of the river. This is accomplished by pouring water out of the can and replacing' it with water from the river, and often takes some time, and many changes. It ■is only necessary to state that a difference, of over two degrees will kill every fish,’ to show the importance of the above, indeed, many fish must have been killed by liberators at times simply owing to their ignorahee of this point. The system of liberation is based on the fact that three or four tiny fish are unnoticed by big trout, eels, etc., as being in no sense a meal. To liberate young fish of any sort in a body is a great mistake. They invariably form a shoal, and naturally attract attention which their enemies are not long in giving to them.

The present-day liberator passes along the river with a receptacle of fish. Here

and there, wherever he finds a quiet little shallow, he dips out a very few, never more than six. It takes a long time, but the results that follow prove it to bo the right one. Indeed, the <»i= cellent waters of South Taranaki were made by this process. The little fish now fend for themselves. Never having been artificially* fed, their natural instinct teaches them what to look for and what to eat. They are spread all over the river, so there is food for all. They thrive and grow in their new environment at an enormous rate in this Dominion, and nowhere in it is there better trout water than in Taranaki. The secretary of the Acclimatisation Society (Mr. Vai. Dull, New Plymouth), would be glad to hear from gentlemen willing to assist in liberating fish, especially in the following districts:— Opunake. Inglewood, Okato, Warea, Lepperton, Oaonui.