DELIVERY AND STORAGE OF SPERM AT FIRST MATING OF FEMALE CHIONOECETES-OPILIO (BRACHYURA, MAJIDAE) IN RELATION TO SIZE AND MORPHOMETRIC MATURITY OF MALE PARENT

Virgin female Chionoecetes opilio were paired with males, in a noncomp etitive laboratory setting, less than 12 h after molting to maturity. The quantity of sperm that females received and stored was measured as ejaculate weight and number of sperm cells. Females copulated 1-4 tim es prior to spawning; the first and second intromissions lasted an ave rage of 34.4 and 37.7 min, respectively. On the whole, the weight of e jaculate and number of sperm cells did not differ between the left and right spermathecae. The number of sperm cells received or stored in s permathecae was independent of male and female carapace widths. Morpho metrically mature (large claw) males transmitted an estimated 10.8 x 1 0(6) sperm cells to each spermatheca, and an estimated 2.1 x 10(6) spe rm cells from each spermatheca were used to fertilize the first egg cl utch (approximate to 70 sperm cells per oocyte). Females did not extru de eggs when fewer than 1.9 x 10(5) sperm cells were delivered to at l east one spermatheca, resulting in a ratio of < 7 sperm cells per oocy te. A median of 10.2 x 10(6) and 8.7 x 10(6) sperm cells were stored p er spermatheca by females that extruded eggs after mating with morphom etrically immature (small claw) and morphometrically mature males, res pectively. The ratio of number of sperm cells to ejaculate weight was significantly greater in stored ejaculates from morphometrically immat ure males than in those from morphometrically mature males. Both male morphs mated successively with 5 different females over a period of 14 -33 days, with no significant change in the weight of ejaculate or the number of sperm cells stored by females after spawning.