Going Solo: Discovery of the First Parthenogenetic Gordiid (Nematomorpha: Gordiida)
Gordiid adults normally pair and mate in aquatic environments such as rivers, streams, lakes, and ponds. Ovipositioning begins within hours to days and can last as long as 2–3 weeks and produces several million eggs. Larvae hatch within 10–14 days, are non-buoyant, and do not swim. Upon consumption, using their proboscis, larvae penetrate and encyst within a wide variety of aquatic animals, including fish, snails, crustaceans, and aquatic insect larvae. Of these hosts, only aquatic insect larvae transport the cysts to the terrestrial environment after metamorphosis (dashed line), where the hosts and the cysts are consumed by the insect definitive host. Many hosts containing cysts, such as snails, which are not normally consumed by the definitive host, are considered dead-end hosts. Within the definitive host, cysts excyst and the larvae penetrate and develop within the hemocoel. Upon maturation, worms manipulate host behavior to jump into water, enabling the worms to make a successful transition from the terrestrial to the aquatic environment.