The result of evolutionary limb loss on the complement of motor neurons in a crayfish limb nerve revealed by serial homology

摘要: Many macruran decapod crustaceans show sexual dimorphism of abdominal appendages adapted for use as secondary reproductive organs. Not only does the Australian crayfish, Cherax destructor, no external, dimorphism, but both males and females have lost pleopods first segment entirely. The nerves ganglia crayfish lobsters carry axons pleopod motor neurons. We used intracellular cobalt infusion into second to reveal neuron complement these in females. approximately 37 neurons associated with them. homologous segment, where there are pleopods, 8 or 9 evolutionary implications this difference discussed.