PROCEEDINGS OF SECTION D. 279 



4.— AN ACCOUNT OF SOME EXPERIMENTS IN THE 

 ACCLIMATISATION OF TWO SPECIES OF AUSTRALIAN 

 FRESHWATER PERCH. 



By David G. Stead, F.L.S., Superintendent of Fishery Investigation, 

 New South Wales State Fisheries Department. 



Introduction, 



In the following paper, a brief account is given of three experi- 

 ments in connexion with the transferral of two species of Fresh-water 

 Perch, indigenous to Australia, to waters in which they did not previously 

 exist. The two species dealt with were the Mountain or " Macquarie " 

 Perch, Macquaria australasica Cuv. and Val., and the Australian Bass 

 or Eastern " Fresh-water " Perch, Percalates fluviatilis Stead. 



The Mountain or Macquarie Perch is a very variable species 

 occurring in considerable abundance in the waters of the great Murray 

 River system. A small variety of it (usually of a dark colour) is also 

 found inhabiting a number of our east-flowing streams, such as the 

 Shoalhaven River, the Hawkesbury River, the Hunter River, and 

 their tributaries, and probably a number of the others farther north. 

 In the western rivers of New South Wales it penetrates far up into the 

 highlands — in the Murrumbidgee and its feeders for instance, being 

 found within a few miles of their respective sources. The fish attains, 

 exceptionally, a weight of as much as 5 lbs., and is often taken at 

 between 2 and 3 lbs. Its flesh is of fine flavour and consistency, and is 

 very white, and altogether it is a very estimable fish. 



As a sporting fish, the mountain or Macquarie perch may hardly 

 compare with the Australian bass, but it is very highly valued by anglers 

 and riverside residents familiar with it, as its capture forms a pleasant 

 alternative to the pursuit of the rainbow trout (in a number of the 

 west-flowing waters of the southern tableland of New South Wales), 

 and the Australian bass (in eastern streams). This perch is usually 

 taken by rod and line, with a worm or other live bait. 



In shape it is somewhat "thick set " and high in the body, with 

 large scales and large eyes, a rounded tail, and a very " snub " nose. 

 The mouth is relatively small, and the upper profile of the head is 

 usually excavate or concave ; this, with the high body, giving to the 

 fish the " roach-back " shape, often spoken of. 



The mountain or Macquarie perch varies in coloration from a 

 dark silvery (or even occasionally a somewhat whitish appearance) 

 to a dark brownish-black, according to the nature of the waters in which 

 it is found. In certain lowland waters like the Kyalite or Edwards 

 River, a very common, noticeable feature of the fish is its white iris, 

 from which comes a familiar name of white-eyed perch. This feature 

 is not seldom to be seen in examples from other localities also. 



