. B Fig. 38. Percentage length frequencies of A'^. ramsayi taken (A) between 51 and 100 m., and (B) between loi and 150 m., in spring. We have no extensive autumn data for the smallest Notothenia ramsayi, but the pooled length frequencies of spring samples taken in 51-100 and 101-150 m. show such strong modes about 8-10 cm. (with the larger fish in the deeper water) that it is reasonable to assume that they represent a year class. These fish are thought to have been almost one year old—o-group becoming I-group (Fig. 38). In autumn we obtained eleven rich hauls of between eighty and 1616 indivi
. B Fig. 38. Percentage length frequencies of A'^. ramsayi taken (A) between 51 and 100 m., and (B) between loi and 150 m., in spring. We have no extensive autumn data for the smallest Notothenia ramsayi, but the pooled length frequencies of spring samples taken in 51-100 and 101-150 m. show such strong modes about 8-10 cm. (with the larger fish in the deeper water) that it is reasonable to assume that they represent a year class. These fish are thought to have been almost one year old—o-group becoming I-group (Fig. 38). In autumn we obtained eleven rich hauls of between eighty and 1616 individuals of this species, and on plotting the percentage length frequencies (Fig. 39) it appeared that modes at around 14-16 and 22-23 cm. recurred with such consistency that there can be little doubt that they represented year classes. They are thought to indicate I-group and I I-group fish respectively. The scale of the figure is necessarily much reduced, in order to permit comparison of all the samples on one page. Table 33, summarizing the important points arising from Fig. 39, and giving relevant geographical data, has been prepared to cover any loss of information due to the unavoidably small scale of the figure. It will be seen that clear evidence of either or both of the two year classes mentioned is provided by all but three of these samples notwithstanding their diverse locations. At St. WS83 there was a strong mode at 17 cm.— considerably higher than the modal values for most of the presumed I-group fish captured around that time, which were at 14 and 15 cm. It is believed that this is explained by the geographical position of St. WS83—close in to, but on the southern side of, the Falkland Islands, considerably farther south than any other station at which such small A^. ramsayi have been taken in quantity. From the general distribution of the species as already described it seems at least highly probable that only the largest members of the I-group would be likel
Size: 1545px × 3234px
Photo credit: © The Bookworm Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, booksubjectocean, booksubjectscientificexpediti
