Male spear squid birthdate impacts mating tactics, with early-hatched becoming consorts and late-hatched becoming sneakers.

New research shows male spear squid (Heterololigo bleekeri) birthdate determines their mating tactics. Early hatched squids become "consorts," fighting for mating opportunities, while late-hatched squids become "sneakers," using clandestine tactics. This discovery can help researchers understand the impact of climate change on squid populations and marine resource management.