#sperm storage

Benefits of Sperm Freezing

The genitalia of the Callosobruchus analis beetle. It is covered in spines from base to tip and may help remove sperm from the sperm storage structures.. Referenced in Rönn, J., Katvala, M. & Arnqvist, G. 2007. Coevolution between harmful male genitalia and female resistance in seed beetles. Proceedings of the National Academy of Sciences 104, 10921-1092. and Hotzy, C. & Arnqvist, G. 2009. Sperm competition favors harmful males in seed beetles. Current Biology 19, 404-407.

How females store sperm

The science of breeding chickens has revealed part of the mystery of how certain female animals are able to store sperm long-term. Droplets of fat transferred from female cells to sperm cells may contribute to keeping sperm alive.

Females of some types of insects, reptiles, and birds can store sperm from multiple males within specialized sperm storage areas of their reproductive tracts. Different animals can store sperm for days or years. Stored sperm can fertilize multiple eggs over time, meaning females do not need to mate again to fertilize additional eggs.

"Farmers may be able to more successfully breed their flocks if we could understand how the sperm stays viable in the sperm storage tubules of female chickens. Fertility studies like this are especially relevant to countries that breed native chickens with lower reproductive rates," said Yukinori Yoshimura, Ph.D., leader of the Research Center for Animal Science and Professor in the Graduate School of Biosphere Science at Hiroshima University.

A. Huang, N. Isobe, T. Obitsu, Y. Yoshimura. Expression of lipases and lipid receptors in sperm storage tubules and possible role of fatty acids in sperm survival in the hen oviduct. Theriogenology, 2016; 85 (7): 1334 DOI: 10.1016/j.theriogenology.2015.12.020

A female brownbanded bamboo shark (Chiloscyllium punctatum) has produced a baby after storing sperm for at least 45 months, which according to researchers may be the longest known incident of sperm storage among sharks - the previous longest known incident at 28 months in a species of dogfish.  

The birth took place in January 2012 at the Steinhart Aquarium of the California Academy of Sciences, where the captive shark could only have mated three and a half years before. Scientists analysed the genetics of the pup and concluded it was fertilised as a result of long-term sperm storage, with their results published in the latest issue of the journal Fish Biology.