LECTURE GIVEN ON TROUT CULTURE.

Star (Christchurch), Issue 18546, 21 August 1928, Page 3

LECTURE GIVEN ON TROUT CULTURE.

MR D. HOPE TALKS TO ADDINGTON BURGESSES.

An interesting lecture on the life history of the tyout was given by Mr D. Hope, curator of the Acclimatisation Society’s’gardens, to the members of the Addington Burgesses’ Association last evening. In introducing the speaker. Mr P. J. Molloy, the chairman, drew attention to the remarkable experiment made by Mr Hope in producing hj-brid trout that lived areproduced their kind. “The great debt we owe to the old pioneers in the manner in which they stocked the rivers is hardly realised." said Mr Hope. “The first shipment of ova was obtained from Tasmania, and that was the nucleus of the undertaking now known as the Acclimatisation Societ}-. It was a very difficult matter in those days to transport the fish, and consequently very few ova reached the hatching stage. The second shipment was more successful, about 400 eggs maturing.” The speaker said that although there were a great many anglers very few knew the life history of the fish they caught. In the autumn the mature fish put on as much condition as they could and started going upstream, the male fish preceding the female. The male fish were very pugnacious and would fight away an>’- intruders. The speaker defined the most favourable localities for spawning, namelj' swiftly running water and a shallow shingle bed. The hatching, he said, depended on the tempera of the water. When the eggs were hatched the ova had a yolk sac on which to live. lie traced the various evolutions through which the ova passed until maturity and said that better results were obtainable by artificial spawning than by nature. Trout were very prolific, said the speaker; roughly speaking, a three-pound trout would produce 3000 eggs. In nature * probably not more than 25 per cent would come to maturity, whereas by artificial spawning a greater number could be obtained. A Russian was the first person to discover the art of artificial spawning. The ej-e of the fish showed out of the ova on the eighteenth day, on the thirty-fourth day the eggs hatch and it took three weeks from the hatch to the fry stage. This was when they had to be fed. Artificial feeding had not the same good results as the natural, continued the speaker, and feeding had a great influence on the growth of trout. The more trout were fed the quicker they grew, a great deal depending on the quality of the food. The introduction of trout into New Zealand was a phenomenal success. The vast quantities of whitebait, natural food were responsible for this. The trout followed the whitebait upstream and thus had a good supply of food all the summer. In the old days, the speaker said, good catches of large fish were obtained in the upper reaches of the rivers. There has been a gradual decline in the whitebait supply, and it is a peculiar coincidence that there has been a, decline in the trout as well.

“Our fish stocks are deteriorating at a rapid rate. We have the finest trout fishing, in some localities, in the world; unless there are some means taken by the Government, in the form of prohibitive legislation on whitebait canning, to preserve the whitebait, the natural food of the trout,” said Mr Hope, “the whitebait, will die out. Thirty tons of whitebait came from . the West Coast last \-ear; the Government should enforce a prohibited season, say three months. It would go a long way towards helping the trout fishing sport. The New Zealand anglers are very fortunate in the fishing the\* have at hand, and it is up to them to see that they do not lose their heritage," concluded the speaker. Mr Hope answered a number of questions dealing with whitebait, and was accorded a hearty vote of thanks for his lecture.