3S0 • DISCOVERY REPORTS 



20-45 ft-, is the principal method of capturing Thyr sites. Fishing is chiefly performed under sail at 

 speeds not exceeding 4 knots, after a school of the fish have been located. In Tasmania similar methods 

 are employed, but rank second in importance to the 'jig-stick', by which the fish are swung directly 

 inboard on to a fore-and-aft chute, after snatching at a lure trailed on a very short trace attached 

 directly to the end of a flexible pole. This interesting method of fishing bears an obvious relation to 

 trolling, and also to the methods employed in hooking tunny and albacore off the Californian coast. 

 (Most of the operatives in this latter fishery were Japanese.) In Fisheries Newsletter {ig^z, vol. i, part 2, 

 p. I ) we are told that netting was being supplied to Port Fairy with the object of testing the possibilities of 

 a gill-net method of capturing barracouta. The results of this experiment should be most instructive. 

 Although the Australian fishery has hitherto operated exclusively upon the surface schools of Thyrsites, 

 the occasional occurrence of the species in otter-trawlings, in areas far removed from those fished at 

 present, has been noted. These catches were made in 60-70 fm., i.e. nearly twice the depths in which 

 we occasionally trawled the species off Patagonia. 



Spawning of Thyrsites may take place to the north and east of Tasmania. This is certainly a nursery 

 ground for young fry up to 3 in. in length, which have been abundantly found in stomachs of various 

 large predaceous fishes (including adult Thyrsites) taken in this area. Young Thyrsites of 10-12 in. 

 (.? I or Il-group) have also been observed not far away. 



In Australian waters Thyrsites are often heavily infested with muscle-worms (? nematodes), and 

 these may possibly be one cause of the emaciation that leads to afflicted fish being described as * axe- 

 handles '. I should be inclined to suspect the extreme seasonal fluctuation in condition, so well known 

 in South Africa, as the main factor, for repeated attempts to correlate parasitic infection with loss of 

 condition in numerous species of fishes have broken down when strict tests are applied. A disease of 

 Thyrsites known as 'milkiness', due to protozoan infection, presents a more serious problem, and is 

 now causing some concern in Australia. In New Zealand it is stated that Thyrsites occurring in northern 

 waters are much subject to disease (Phillipps, i92i,p. 118). Now the fish are less common in the north, 

 but the whole stock will tend to move northwards in winter, and, moreover, they are believed to 

 spawn even earlier off New Zealand than they do off South Africa (August rather than September: 

 Phillips and Hodgkinson, 1922, p. 94). Hence it is probable that natural seasonal loss of condition is 

 at least partly responsible for reports of disease. 



In the New Zealand fisheries ' barracouta ' are not so important as in Australia and South Africa, 

 doubtless owing to the good supply oi Jordanidia solandri (' southern kingfish', ' hake ' !). Comparable 

 figures for the whole country are not available, but separate returns for Thyrsites atun have been made 

 at a few of the individual ports. Wellington shows the highest of these returns, and from the Fisheries 

 Reports of the Marine Department it can be seen that Thyrsites formed from 2 to 4% of the total 

 catch here over several years between 1931 and 1938. During the best years this figure represents over 

 1000 cwt. 



The common names applied to Thyrsites are used for other fishes so promiscuously as to lead to the 

 possibility of endless confusion to anyone not personally acquainted with these other fishes as well, 

 so I have thought it best to treat this matter in detail : 



T. atun (Euphrasen), a gempylid, has three main vernacular names in different parts of its wide 

 range, that extends round the world in the cooler parts of the southern sub-Tropical Zone. These 

 are snoek (from the Dutch word first applied to the European fresh-water pike, Esox lucius) in South 

 Africa excepting Natal; 'barracouta' (from barracuda, first applied to the marine Sphyraenidae in 

 Europe and the West Indies) in Australia and New Zealand ; and sierra (from Spanish, lit. a saw, 

 applied chiefly to ' king- ' or ' spanish-mackerels ' elsewhere) in Chile. These names are all descriptive: 

 snoek relating to the superficial resemblance between body-form and pointed, formidably toothed, 



