INTRODUCTION 235 



Apart from the direct distributional study, the sex, lengths and maturity stages of all hake captured 

 were recorded. The great difficulty of recognizing clear-cut stages in the development of the ovaries 

 of these fish first became apparent at this point. The difficulty of standardizing such observations on 

 this subject as are possible by direct inspection remained a handicap throughout. Probably it can 

 only be tackled by large collections for subsequent microscopic examination such as Hickling (1930ft, 

 1935ft) developed during his prolonged work on the European species. Hickling found it possible to 

 distinguish major stages by naked-eye appearance, but our observers agreed that this was never 

 satisfactory with females of the Patagonian species. These are only slightly smaller than the European 

 fish, but they often mature when considerably smaller, with a consequent increase in the amount of 

 overlapping of ovarian developmental stages among fish of the same length class. Hickling was 

 working upon a single species, but a limited staff investigating virgin ground could not make a large 

 enough systematic collection of ovaries without neglecting other essential work. 



On the winter survey female hake were markedly more numerous than male. As in the autumn 

 the males were associated with the smaller females, and very few males were taken where large females 

 preponderated. The majority of the smaller females were immature. Very few of the large females 

 were ripening, and the majority seemed to be 'spent'. Among niales the proportion of immature to 

 mature fish was roughly 3:2. Very few were 'ripe and running'. 



The hake were found to be feeding very largely upon Euphausiidae, Clupeafuegensis, Notothema spp. 

 and squids. Apart from hake, no fish were taken in such quantity as to be considered of possible 

 commercial importance. Notothenia ramsayi were fewer than on the autumnal survey, and the best 

 catches were taken on the same grounds as the hake. All were measured and sexed. There was a 

 marked preponderance of females. Cottoperca gobio seemed to favour the rich invertebrate area to the 

 south of the Falkland Islands, but was found elsewhere as well. 



Some seven or eight species of Rajidae were observed. Raja brachyurops being the commonest. 

 Very full notes on the large range of variation to be found among the members of this group 

 were made These were of great value later, when our data were brought into line with Norman's 

 revised taxonomy of the Patagonian species. Salilota australis was taken quite frequently (fifteen 

 stations), mostly in the more northerly part of the area, but in small numbers. Specimens of three 

 species of rays and two species of Zoarcidae, all new to science, were obtamed during the second 



survey. ,,-11 c 



Three well-defined associations of invertebrates were observed, correlated with three types ot 

 bottom deposit. Along the edge of the shelf north of the Falkland Islands to 45° S a fine green sand 

 giving a clean bottom for trawling was prevalent in depths of 150-300 m. This ground was very rich 

 in the smaller invertebrates-small ophiuroids, echinoids, other echinoderms, Serohs, amphipods, 

 cumaceans and ostracods. Small quantities of Cephalodiscus occurred at seven of these stations. The 

 Falkland trough yielded similar results but without the vast numbers of small ophiuroids, in slightly 

 greater depths of water. Both these grounds yielded bigger quantities of hake and of rays than the 



other areas worked during the winter. . . . , , . , 



On the continental shelf to the north, west and south-west of the Falkland Islands there was darker, 

 coarser sand, often brown, with pebbles and shells. Some patches were heavy with large invertebrates 

 such as sponges and molgulids, and others comparatively clean. The invertebrates were heaviest close 

 in to the Falkland Islands, and especially to the west of the Jason Islands. . ^ ^ 



The coastal waters to the south-west, south and south-east of the Falkland Islands again showed a 

 strikingly rich invertebrate fauna of sponges, hydroids, coralline hydroids, Alcyonana and Polyzoa. 

 This sheltered a rich fauna of smaller invertebrates: holothurians (especially Synapta), polychaetes 

 and small Crustacea. Here the bottom was of light green sand with pebbles, shells (many of pectens), 



