One of the most fascinating topics in animal copulation is semelparity, or suicidal reproduction, whereby one (usually the male) or both of the parents die after reproducing. Both male and female Pacific salmon die after reproduction—the same goes with octopus. Female praying mantis and Black Widow spider kill and eat their mate after sex.
You seriously need to applaud them for their determination. Or rather, desperation.
|Male marsupial mice, Antechinus stuartii, are overtly preoccupied with copulation and die abruptly at the conclusion of the mating season. Image: www.siumed.edu|
And as if losing their balls and having a restricted mating period were not miserable enough, their stored sperm gets diluted in their urine and will eventually lost if they're not used for sex. Now that explains the desperation.
Info: Diana O. Fisher, Christopher R. Dickman, Menna E. Jones, and Simon P. Blomberg, Sperm competition drives the evolution of suicidal reproduction in mammalsPNAS 2013 DOI: 1310691110v1-201310691.