Linguatula serrata

Linguatula serrata is a parasitic arthropod infecting a wide range of mammals. Its life cycle is indirect, with adult parasites residing in the upper respiratory tract of carnivorous vertebrates and humans, and releasing eggs through nasal secretions and/or feces into the environment. Herbivores serve as intermediate hosts, becoming infected by accidentally ingesting pasture contaminated with eggs. Larvae emerge in the intestine, encyst in visceral tissues (e.g., liver, lungs, mesenteric lymph nodes), and undergo several moults before becoming infective. The definitive host must consume these nymphs to complete the life cycle, which usually occurs through predation or scavenging for carnivorous hosts, or by consuming raw or poorly cooked meat or offal for humans. Once ingested, the nymphs move from the digestive tract up the esophagus to the nasal cavity, where they develop into mature adults. Mature female adults may attain 8.5 cm in length, while males are smaller at 1.5–2.0 cm.