91)2 KEPORT OF COMMISSIONER OF FISH AND FISHERIES. 



is essential, there is uo lake in New Zealand where there is a chance of 

 this fish being successfully reared. But if the absence of the extreme 

 cold will only lead to a more rapid development of the embryo, there is 

 no reason to doubt that some, at least, of the larger and deeper lakes, 

 such as Wakatipu and Wanaka, and especially Te Anau, will prove suit- 

 able. The waters of Lake Erie attain a surface temperature in summer 

 of 75°, at which season the whitefish return to the cool, deep waters ; 

 but in other lakes, which are deeper and without undercurrents, at that 

 season the whitefish run to the shores, and especially to the entrance 

 of rapid rivers, or a broken, rocky coast, where the splash of the waves 

 favors more thorough aeration of the water. 



The surface water of the above-mentioned New Zealand lakes has 

 rarely a higher temperature in summer than 52°. On the 6th instant, 

 Mr. Worthington ascertained the temperature of the embayed surface 

 water at Queenstown, Lake Wakatipu, to be 53<3 at sunrise and 55° at 

 2 p. m. In winter I found the surface temperature at the same place to 

 be about 46^^, and, although we have no information on this point, it is 

 probable that much colder water is to be found at all seasons in the pro- 

 found depths of this and all the great lakes of the south, so that, as far as 

 mere temperature is concerned, the whitefish would feel at home, pro- 

 vided the winter temperature on the gravelly banks, where the rivers 

 enter the lakes, is sufliciently low for the proper development of the 

 ova. 



It is very desirable, however, that the experiment should be tried 

 under the most i^romising conditions. 



The first shipment having been hatched out at Christchurch, I recom- 

 mend that the whole of the young fish obtained should be placed in Lake 

 Coleridge as soon as they can be removed, and that the shipment ex- 

 pected by next mail-steamer should be forwarded, with a sufficient quan- 

 tity of ice, to the Makarewa Ponds to be hatched, and the young fish 

 transferred to the Te Anau and Wakatipu Lakes. As the shipment will, 

 no doubt, arrive, like the last, in one parcel, and the chance of success 

 in the south is so much greater, provided there is a sufficient supply of 

 ice available, I cannot recommend that this second consignment of ova 

 should be intrusted to the Auckland Acclimatization Society. 



Their application is for the purpose of stocking Taupo Lake, but I find 

 that the water at the outlet of Taupo Lake only varies from 54° in win- 

 ter to 63° in summer, which differs so materially from the conditions 

 that control the natural distribution of the fish that there would be very 

 small chance of their thriving. 



The chief difficulty in propagating the whitefish arises from the oir- 

 cumstance that the ova are coated with an adhesive mucus* that renders 

 their manipulation more difficult than in the case of salmon ova. The 

 young fish are also more difficult to rear, and it has never been success- 

 fully done yet, except by turning them adrift in suitable water at a very 



* This is an error. The difficulties in hatchinor whitefish arise from other causes. 



