Failing to find a mating partner is a
dent1 to the reproductive
prospects2 of any animal, but in the flatworm species Macrostomum hystrix it might involve a real headache.
Zoologists3 from the Universities of Basel and Bielefeld have discovered the extraordinary lengths to which this animal is willing to go in order to reproduce - including
apparently4 injecting
sperm5 directly into their own heads. The academic journal
Proceedings6 of the Royal Society B has published their findings. The absence of a mate usually spells disaster for sexually reproducing animals. However, some simultaneous hermaphrodites - animals who have both male and female sex organs at the same time - have developed an escape route for this
scenario7: self-fertilization. It is an imperfect solution, as any offspring produced by so-called "selfing" are bound to be inbred, but still better than not reproducing at all.
In previous studies, it had been established that the flatworm species Macrostomum hystrix is capable of switching to just such selfing behavior when
isolated8 from mating partners, a behavior found in many but not all simultaneous hermaphrodites. In their new study, Dr. Lukas Schärer from the University of Basel and his team now show the bizarre, yet
remarkable9 mechanisms10 Macrostomum hystrix has developed that make this possible.