The size range of sperm bundles in aeshnid dragonflies (Anisoptera: Aeshnidae)

Sperm bundles of alternative size and number of sperm cells are regularly found in the spermiducts of aeshnid dragonflies. This arrangement can be traced to earlier stages of spermatogenesis, where the number of generations of spermatogonia does not appear strictly determined. This is considered an archaic feature of the order Odonata. Dragonfly spermatogenesis is discussed.