. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. REPRODUCTION OF URTICINA LOFOTEN SIS 465 *S 70 -70 IL 60 60 o 12 >• H 50 -, 1 50 O >• Z O 40 " -. 40 111 O C • 2 O 30 o O • r • r 30 m U r - u • • Jr O 20 -i — - - 20 IL K _ " Tn r "3 r < 10 -, r w r 10 -" 5 1 Jl 0 c I N 0 i F M A M J J A s ' o n: 4 5 65 3563265 1 976 1977 FIGURE 6. Histograms showing the proportion of large oocytes among the 50 cells measured from each female specimen of Urticina lofotensis. Each histogram represents an animal. One of the females collected in February and one co
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. REPRODUCTION OF URTICINA LOFOTEN SIS 465 *S 70 -70 IL 60 60 o 12 >• H 50 -, 1 50 O >• Z O 40 " -. 40 111 O C • 2 O 30 o O • r • r 30 m U r - u • • Jr O 20 -i — - - 20 IL K _ " Tn r "3 r < 10 -, r w r 10 -" 5 1 Jl 0 c I N 0 i F M A M J J A s ' o n: 4 5 65 3563265 1 976 1977 FIGURE 6. Histograms showing the proportion of large oocytes among the 50 cells measured from each female specimen of Urticina lofotensis. Each histogram represents an animal. One of the females collected in February and one collected in September contained only small oocytes. proportion of large oocytes. Percentage of large cells in most females had dropped considerably by October. Maximum female GI was in a g animal collected in November. The largest female, from the June collection, had a weight of g and a GI of ; the smallest female, taken in October, weighed g and had a GI of Average female GI gradually declined from November to its nadir in May, generally par- alleling the pattern in males and surface water temperature (Fig. 7). Although it had just begun to increase (Fig. 6), large oocyte frequency was also low in May, when oocytes less than 200 ^m in average diameter were predominant (Fig. 5). The gonad cycle of males is shown in Figures 7 and 8. In April, when the largest male, weighing g (GI ), was collected, and in May, when the smallest, weighing g (GI ) was collected, gonad indices were low and males contained only spermatogonia. The first sperm had developed by June when, as with females, GI abruptly increased. From an August low (based on one male with 47 pairs of mesenteries, several residual sperm packets in its immature gonads, and a GI of ) almost equal to that of May, male GI increased through October, with a 3 Z O O 16 14 12 10 8 6 4 2 0. N 4 2 15 10 D s s 1976 7 3 1977 F M A M J J A SO 8 356327$ females 3 234(12
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
