 In a resistant host, the third stage larva can invade tissue and persist, eventually infecting offspring in females either in milk or prenatally.This phenomenon, well-studied in trichostrongyles of herbivores and known as "arrest", occurs in several hookworm species such as "Ancylostoma caninum" in canids, "Uncinaria lucasi" in fur seals and "Ancylostoma duodenale" in humans.These have large buccal capsules and leaf-like structures known as "corona radiata".