THE OLDER STAGES I9i 



Even if the pronounced scarcity of eggs at South Georgia were by itself not enough to warrant this 

 at first sight paradoxical conclusion, for there is always the possibility that they might have been 

 concentrated there at some critical depth, for instance, on or near the bottom, where our sampling is 

 inclined to be less thorough than it is in the upper layers, our almost complete failure to find any 

 evidence of hatching, to which the absence of Nauplii and the capture of only two Metanauplii 

 (Table 40) bear ample witness, points to its being the most reasonable inference that can be drawn. 

 As Marshall and Orr (1955, p- 70) have said of Calanus finmarchicus, 'the presence of males and the 

 presence of females with spermatophores have both been taken as signs that active breeding is going 

 on but events in East Greenland show that they are not necessarily so. The only safe indication is the 

 presence of eggs, nauplii or young copepodites'. Simpson (1956) writes in similar terms on the 

 spawning of fish, noting that the 'systematic determination of the distribution of the youngest 

 pelagic stages [including the eggs] of any fish . . . provides a means of delimiting with very considerable 

 precision both the time and position of spawning'. It might be observed too that our virtually com- 

 plete failure to find eggs in these island waters cannot be ascribed to a wholesale neglect of the levels, 

 perhaps the critical levels, adjacent to the floor of the sea. For although the near-bottom stratum in 

 the deep oceanic water of the South Georgia area was in fact left entirely unexplored the corresponding 

 stratum closer inshore was by no means so completely neglected. Between November and March 

 90 stations were made in water less than 1000 m. deep, deep nets (Table 41) coming within 50 m. of 

 the bottom at 79, or 88 %, of them, the average proximity of approach being as little as 22 m. 



Table 41. Nearness of approach of deep nets to the bottom in the 



shallow waters of the South Georgia whaling grounds 



Nearness of approach No. of nets 



(m.) 



Not only does the absence of any substantial deep living larval community indicate how insignifi- 

 cant in this field the scale of the hatching must be, but it also suggests, and suggests very strongly, 

 that such few surface larvae, Calyptopes and early Furcilias, as from time to time have been recorded 

 here from January to March (Table 40) must get carried to the island in the surface stream. Through- 

 out the breeding season our vertical gatherings of young surface forms in this neighbourhood have 

 consistently been small or negligible, only one in fact of the relatively enormous series of net hauls 

 we made yielding a really substantial catch, this single gathering, a March one, of 707 Calyptopes, 

 accounting for nearly 60% of the total Calyptopes and early Furcilias recorded round the island since 

 work there first began. Even this, for South Georgia, exceptionally large vertical gathering is 

 unlikely to have been produced in situ, to have sprung in other words from a local hatching or local 

 spawning, it having been obtained in the surface stream to the south-east of the island, well away 

 from the land and well into the tongue of Weddell water (p. 58, Fig. 4) that approaches it from that 

 direction. 



Ruud (1932) is also of the opinion that in so far as the major aspects of the spawning are concerned 

 the South Georgia region does not come into the picture and that the krill population there cannot, 

 therefore, be of local origin but must spring from surface-borne incursions of larvae born in higher 

 latitudes in the Weddell Sea. He writes, ' If E. superba spawns under and near the drift ice, its proper 

 spawning ground is the zone of the pack-ice, and as a rule the conditions off South Georgia are not 



