. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. SEXUAL COMPETITION IN BLUE CRAB 375 165 155 145 135 125. 1992 1993 Year 1994 o 3-° I, •53 Figure 7. Sizes of adult females (•) and paired males (A) and weight of female spermathecae (O) between 1992 and 1994. Results of Tukey comparison tests for differences between years are as follows: for females—1993 > 1992 (P = ): 1993 > 1994 (P 1992 (P = ), 1993 > 1994 (P 1994 (P 1992 (P 1994 (P 1994 (P = ). Vertical bars are ±1 standard error. ejaculate weight in mating 1) increased with the interva
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. SEXUAL COMPETITION IN BLUE CRAB 375 165 155 145 135 125. 1992 1993 Year 1994 o 3-° I, •53 Figure 7. Sizes of adult females (•) and paired males (A) and weight of female spermathecae (O) between 1992 and 1994. Results of Tukey comparison tests for differences between years are as follows: for females—1993 > 1992 (P = ): 1993 > 1994 (P 1992 (P = ), 1993 > 1994 (P 1994 (P 1992 (P 1994 (P 1994 (P = ). Vertical bars are ±1 standard error. ejaculate weight in mating 1) increased with the interval between the first and second matings (Fig. 9) but not with that between the second and third matings (;i = 19. P = ). The interval between the first and second matings did not differ significantly from the interval between the second and third matings (/ = , df = 36, P = ). Copulation duration There was a significant effect of copulation duration (F4,5 == , P < ) but not male size (,5 = , P = ) on the amount of ejaculate passed to females. The interaction between male size and copula- tion duration was not significant (Fx^i — , P = ). Males that copulated without interruption (8- 12 h) passed larger ejaculates than males that were inter- rupted after 1, 2, or 4 h; males that were interrupted after 8 h passed larger ejaculates than males interrupted after 1 or 2 h (Fig. 10). No significant difference was found between the size of ejaculates passed by males that were interrupted after 8 h and that of uninterrupted males (df = 37, Tukey HSD = ). Discussion In the field, paired males were larger than unpaired males in each year except 1994, and there was consistent, positive assortative mating between males and pre-molt females. The discrepancy in the results for 1994 may be the result of cold weather in that year, which retarded the growth of crabs and shortened the mating season. Consequently, the mean size of pa
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
