THE OLDER STAGES 135 



Crabeaters, birds and fish. It is rarely encountered on the pack (Wilson, 1907a; Bruce, 1913 ; Brown, 

 1915a ei al.) far away from land. As Wilson (1902) remarks it is essentially a 'shore seal ', not a single 

 specimen he adds having been seen from the 'Southern Cross' (Bernacchi, 1901) throughout her 

 voyage in the Ross Sea ice. There can it seems, therefore, be little justification for the statement by 

 Ekman (1953) that E. superba forms 'a considerable part' of the food of this exceedingly abundant 

 coastal species. 



Pouting (1923) vividly describes the feeding of the Adelie penguins at Cape Royds, the parent birds 

 in a continuous flow streaming landwards over the fast ice, their stomachs ' swollen with the load ' of 

 Euphausia they had gathered for their chicks. Here again, however, as with Lindsey's Weddells and 

 Crabeaters, it must have been E. crystallorophias they bore. And it must be to this species too that 

 Grifiith Taylor (1930) refers in his note on the teeming wealth of Euphausia off Cape Crozier among 

 which hordes of Adelies hunt and feed, and this the ' Euphausia ' so often reported^ to be supplying 

 the multitudes in McMurdo Sound. 



Dell (1952) states that the Emperor penguin, at least for part of the year, feeds almost 'entirely' on 

 E. superba. There is nothing, however, in Antarctic ornithology or narrative to suggest that the krill 

 ever feature thus largely in the diet of this predominantly squid-eating bird. It may it is true be 

 responsible for some minor measure of depredation, particularly it would seem during its periodic 

 wanderings off on to the pack. Falla (1937) for instance records that three birds collected on the ice 

 north of Queen Mary Land in February 1931 'had been in the water fishing for "kril " {Euphausia), of 

 which they contained fair quantities '.^ 



Finally, turning to the plankton, we find indications that even from this the krill may be far from 

 secure. Both Hart (1942) and I have seen single small individuals in the gut of the large Sagitta 

 gazellae, while the ' Euphausiid larvae ' recorded by David (1955) in the gut of this arrow worm would 

 no doubt include some larval krill. Hart, in his Antarctic food chain (p. 45), shows that young 

 E. superba are also included in the diet of the pelagic amphipod, Parathemisto gaudichaudii, which 

 swarms in enormous numbers in parts of the circumpolar sea. Other voracious plankton animals, 

 notably coelenterates, are doubtless also involved, for, as Bigelow(i926) emphasises, the various species 

 of medusae, large and small, all ' belong to the piratical category ', the total destruction they wreak on 

 euphausians, copepods and other animals being ' beyond any estimation '. 



E. superba then manifestly occupies a key position in the economy and ecology of the Antarctic 

 seas. It supports life on a vast scale, a complex variety of life ranging in size from that of the small 

 organisms of the plankton to that of the immense bulk of the blue whale, the most gigantic animal that 

 has ever existed. It must exist in enormous numbers, in an astronomical abundance far exceeding 

 that of any other pelagic euphausian, and while any estimate of its bio-mass (p. 170), in the present 

 state of our knowledge, must involve much speculation there are perhaps some grounds for supposing, 

 as Mackintosh (1934) has written, that in sheer mass of living matter it might be 'equal to all the rest 

 of the Antarctic macroplankton combined '.^ 



1 Murray (1909); Cherry-Garrard (1922); Joyce (1929); Debenham (1930a) et al. 



^ Little is known about the feeding of the King Penguin. Stonehouse (i960) states that it is clear that cephalopods form 

 the bulk of the diet, although it has not yet been possible to determine the species. He notes, however, that Notothenia 

 rossii may be included in the feed, and since this fish is a voracious krill-eater it would not be at all surprising if E. superba 

 were to turn up occasionally in the stomachs of these large birds. 



^ This was written long before the full facts of the distribution of the krill became known and could now only be said to 

 apply, if it does in fact apply, to the macroplankton of the East Wind-Weddell surface stream to which the vast bulk of the 

 euphausian population (p. 61, Figs. 56 and 5 c) is now known to be confined. The bio-mass of the combined macroplankton 

 of the circumpolar West Wind drift manifestly it will be seen vastly exceeds that of the scattered and meagre krill population 

 there. 



