BIO 117P Lecture Notes - Lecture 2: Female Sperm Storage, Damselfly
Document Summary
Waage 1979 dual function of the damselfly penis: sperm removal and transfer. Evidence for sperm displacement is indirect and lacks controls. Three experiments: compared the amounts of sperm in females after one v. two matings. Females were tethered and presented to males. After the copulations, the female abdomens were removed and immediately preserved in 70% ethanol. The external dimensions of the sperm mass were measured with an ocular grid. Was used to determine sperm volume stored by a female. Result the volume for group 1 (one mating) was equal to group 2 (two matings: comparisons of sperm volume in females caught in the field during several stages (i. perching on the shore; ii. Flying in tandem with males before copulation; iii. Results the first three had no difference in sperm volume. The last one had little or no sperm in their copulatrix. There was sperm on the head of the penis.
