Weekend #Plankton #Factoid 🦐🦠
If you see a #copepod #zooplankton with a distinctly wonky bent antenna, it is likely a male. They use this antennule to grasp females during #mating to allow them to place a spermatophore (sperm packet) at the female's genital opening. Only the right antennule of adult male #calanoids is geniculate. Both antennules are modified on adult male #cyclopoids (and harpacticoids). Females lack modified antennae but have a genital pore or carry eggs. #Science #oceanography