Squids' birthday influences mating: Male spear squids shown to become 'sneakers' or 'consorts' depending on birth date

The day a male spear squid hatches determines which mating tactic he will use throughout his life, according to new research. Spear squid (Heterololigo bleekeri) that hatch earlier in the season become "consorts" that fight for mating opportunities. Those that hatch later become "sneakers," which use more clandestine mating tactics. Researchers found that the mating tactic determined by the birth date was fixed for the squid's whole life.