154 NEW SOUTH WALES 



ova — at least so far as the Sacramento River is concerned.* In Ger- 

 many the same efforts are made as in France, and in Sweden also the 

 matter has been taken up very enthusiastically. It is in contemplation 

 to commence something of the same kind in New South Wales, not only 

 for the introduction of useful European fishes, but also for preservation 

 of our own. At the present time the golden perch {Ctenolates auratus) 

 has been much spread through the zeal and industry of Mr. Warren, of 

 Wagga, who in the summer months transmits small boxes of ova to his 

 correspondents. 



It is necessary to mention here that fish ova are subject to many 

 parasites which eft'ectually destroy their vitality. These parasites are of 

 diflferent familes of fungi and alg£B, especially a green conferva belonging 

 to the genus CEdogonhtm. The ova are also very liable to the attacked 

 by the small fungus which is so destructive to the common house-fly 

 and affixes it to our window-panes on a little cloud of floculent threads. 

 This is Saprolegnia ferax, and it is the one which seems to be destruc- 

 tive to many animals besides fish and flies. It stands on a debatable 

 ground between algse and fungi, a quality which it shares with three 

 other genera which infest ova, and these are Aclilya, Pythium, and 

 Aphano7n'i/ces. The only remedy that can be suggested for this mould 

 is to have the water used in hatching previously boiled and the gravel 

 subjected to the same process, not in any case so difficult as at first 

 sight it might appear. Weak solutions of Hyposulphite of soda have 

 been suggested, but no results have been published. It is to be hoped 

 that the Exhibition in 1883 will help to throw light on this question. 



The use of pisciculture need not be confined to fresh-water fishes ; there are 

 many of our sea-fislies to which the art might be most pi'ofitably ajDplied — the sea- 

 mullet for one. What coukl be easier or less costly than to supply the drain and 

 destruction of that most valuable fish by artificial breeding ? Scoop out a shallow 

 space of ground near tlie sea, the bottom about the low-water level, cut a channel 

 of communication with the sea, so that every tide shall flow into it, put a piece 

 of perforated zinc or wire netting across the channel so that nothing can get in to 

 destroy the spawn ; then get a few of the fishes on the point of spawning, squeeze 

 out the roe gently with the liand into a tub with a little waiter in it, upon the roe 

 so deposited squeeze the milt of the male fish, then stir gently with the hand so 

 that every grain may come into contact with the male secretion, place the contents of 

 the tub on the sandy Ijottom of the pond, and cover over with a net to prevent cranes 

 and other water-fowl from disturbing the spawn. In the early spring the young 

 fish will make their appearance, and after a few days' growth they may be turned 

 out and left to their own resources. By the adoption of such a system the most 

 extravagant waste of the old fish can be readily met. The full-sized roe of a 

 single female are estimated to contain nearly 3,000,000 ova, so that the careful 

 preservation of the yield of a very few fish would supply all the markets of the 

 world. Under natural conditions the loss of spawn is enormous ; by the artificial 

 system it is reduced to a minimum. 



There would be little difficulty in keeping up the numbers in the same way of 

 any fishes for which the demand was so great as to risk the extinction of the 

 fishery, provided they were fishes which spawned on our sliallow beaches like the 

 myllet. In that class would be included our best net fishes — the whitings, the 

 garfishes, the sole, &c. — R.R.C. 



It is as well here to draw attention to the larger proportion of eggs in 

 the flat-fishes, which render them particularly favourable for pisciculture, 



* See Report of the Commissioners for Calif ornian Fisheries for 1878-79. The 

 fish is generally believed to be English salmon. Also, Report of the Commissioners 

 of Fisheries of Maryland from 1876 to 1880, where very full diagrams, plans, and 

 drawings of the fish-hatching apparatus and houses are given. 



