Complex suicidal somersault behavior in male redback spiders may be explained by surprisingly simple genetics
The Australian redback spider (Latrodectus hasselti), a cousin of the North American black widow spider, is known to practice sexual cannibalism, which is somewhat common among spider species. However, the male Australian redback has also been observed facilitating the process with strange moves. Despite the complexity of these behaviors, a new study, published in Biology Letters, indicates that…
New research in Biology Letters reveals that a complex mating behavior in male Australian redback spiders, where they perform a somersault to facilitate sexual cannibalism, may be controlled by a single genetic region on the X chromosome. Despite appearing complex, the somersault is a coordinated behavior, not a simple physical feature.
The study also found that abdominal narrowing, a trait that makes it harder for female spiders to bite the male during mating, does not follow a simple genetic pattern and is likely influenced by more complex genetic and environmental factors. The researchers crossed redback spiders with their close relative, the katipo spider from New Zealand, and then backcrossed the hybrids with males from either species.
Analysis of 104 male offspring showed that the mating somersault is inherited from a single X-linked genetic region, while abdominal narrowing does not follow a simple inheritance pattern. This suggests that the two mating traits are genetically separate and encoded by two unlinked loci. The study indicates that dramatic mating behaviors can evolve rapidly and contribute to reproductive isolation between species, even though the redback and katipo spiders diverged only about 100,000 years ago.
Written by urgent.news from Phys.org's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
