Comment on "A sensory system for mating in octopus"

A recent research article by Villar et al. (Science, 2026, 392:96-101; doi: 10.1126/science.aec9652) proposes that mating behavior in octopuses is guided by contact-mediated chemosensation involving progesterone, which is described as a “conserved ovarian hormone.” Although this work is remarkable from the neurobiology, behavior, receptor evolution, and structural biology perspectives, its interpretation raises major questions regarding steroid biology in invertebrates, and more specifically in mollusks.