TELEOSTEI 217 



In the appendix to his work on New Zealand Neuroptera (pub- 

 lished in 1904), Mr G. V. Hudson gives several tables showing the 

 contents of the stomachs of trout. Their principal food appears to 

 be caddis- worms. 



Another interesting fact he brings out is that the larvae of the 

 larger species of dragon-flies destroy considerable numbers of very 

 young trout-fry. 



Mr W. Arthur has investigated the rate of growth more fully 

 and carefully than any other New Zealand writer on the brown trout. 

 He states that the average growth in all Otago streams between 1878 

 and 1883 was 1-53 Ib. per annum. The lowest recorded was in the 

 Otaria 0-751 Ib., and the highest is Lake Hayes, 3-5 Ib. 



The first fish in the Shag River were liberated in 1868, and the first taken 

 were in 1874; a male weighed 14 Ibs., and a female i6| Ibs., representing 

 an average annual growth of 2^ and 2 Ibs. respectively. In the Leith the 

 average increase at first was i| Ibs. per annum; in the Lee Stream i Ib.; 

 in Deep Stream i| Ibs.; and in the Upper Taieri i Ib. These were not marked 

 fish, and the average is based on the assumption that they were among 

 the first fish liberated. In the Shag and the Leith there were great numbers 

 of smelts found in addition to what occurred in the other streams. 



The other three are inland streams, mostly running in rocky gorges. 



In the Avon and Cust Rivers in Canterbury the average yearly 

 growth at first was if Ib. 



Apparently in the large lakes of both islands the growth was much 

 more rapid, but the records were not carefully enough kept to be 

 quite trustworthy. Thus Mr A. J. lies states that the largest brown 

 trout taken out of Lake Rotorua weighed 27^ Ib., "and was netted 

 about eighteen years ago, some four or five years after the brown 

 trout were first liberated." There is good reason to believe that the 

 rate of growth in the early years of stocking was phenomenal, but 

 the record is not definite enough to be accepted. 



Mr W. Arthur points out, however, that similar rapid growths 

 have been recorded elsewhere, and gives this example : 



Mr J. V. Harvie-Brown, of Dunipace, stocked a loch in the north of 

 Scotland, which had no trout in it at all. In two years they multiplied and 

 attained a weight of 4! Ibs. So soon, however, as the number exceeded the 

 food supply, or in two years, they fell off in condition, colour, etc., and 

 latterly were not worth catching. Like cases have occurred elsewhere at 

 home. 



Size of Brown Trout. Anglers are notorious for the extent to 

 which their scales and yard measures stretch when they are recording 

 their catches. But acclimatisation societies and anglers' clubs usually 

 keep pretty accurate records. It is therefore surprising and amusing 



