Discovery reports (1947) Discovery reports discoveryreports23inst Year: 1947 268 DISCOVERY REPORTS 80- > liJ 60 < t; 40 20 Fig. 14. A. (200 m m.) white; also seasonal variation in its frequency of occurrence B on the shelf, and black, and on the shelf C 'over the edge'. Season Spring Summer Autumn Winter Spring Summer Autumn Winter Table 5. Full data relating to Raja brachyurops/)/o«g in Fig. 14 On the shelf, depths less than 200 m. No. of individuals 6 62 74 17 of total caught in each season 60 95 97 14 Over the edge, depths more than 200 m. No. of individuals No. of hauls 14 65
Discovery reports (1947) Discovery reports discoveryreports23inst Year: 1947 268 DISCOVERY REPORTS 80- > liJ 60 < t; 40 20 Fig. 14. A. (200 m m.) white; also seasonal variation in its frequency of occurrence B on the shelf, and black, and on the shelf C 'over the edge'. Season Spring Summer Autumn Winter Spring Summer Autumn Winter Table 5. Full data relating to Raja brachyurops/)/o«g in Fig. 14 On the shelf, depths less than 200 m. No. of individuals 6 62 74 17 of total caught in each season 60 95 97 14 Over the edge, depths more than 200 m. No. of individuals No. of hauls 14 65 42 17 No. positive 3 17 18 3 positive 21-4 26-2 42-9 17-6 4 3 2 106 of total caught in each season 40 5 3 86 No. of hauls 2 10 8 13 No. positive positive SO 10 12-5 38-5 Separate depth-frequency polygons of the type used for summarizing the main features of depth dj nbutton of all elasmobranchs may also be plotted for R. at each season, as m Fig '5 This presents the evidence of seasonal migration even more clearly ' Very good evidence that the young of R. brachyurops are hatched on the shelf can be obtained bv considering our records of captures of minute post-embryos and yearlings less than zo cm wide' The r seasonal distribution also is so circumscribed as to establish the approximate hatching peT od and they are accordingly tabulated in full (Table 6) naicning period, 3oMaThaLTMlv'lltt' 't ''' V'' T'''''''' '' -- -'g between xcfp ons I'o cm Id f T'n . ' '''''' observations were made at other seasons. Of the exceptions, the 9 cm. individual in October was presumably a late-hatched survivor of the previous
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