References


== External links ==
A gapeworm (Syngamus trachea), also known as a red worm and forked worm, is a parasitic nematode worm that infects the tracheas of certain birds. The resulting disease, known as "gape"  occurs when the worms clog and obstruct the airway. The worms are also known as "red worms" or "forked worms" due to their red color and the permanent procreative conjunction of males and females. Gapeworms are common in young, domesticated chickens and turkeys. When the female gapeworm lays her eggs in the trachea of an infected bird, the eggs are coughed up, swallowed, then defecated. Birds are infected with the parasite when they consume the eggs found in the feces, or by consuming a transport host such as earthworms, snails (Planorbarius corneus, Bithynia tentaculata and others)

Morphology
Males and females are joined together in a state of permanent copulation forming, a Y shape (forked worms). They are also known as the red worms because of their color. Females (up to 20mm long) are much longer than males (up to 6mm long). The life cycle of the gapeworm is peculiar in that transmission from bird to bird may be successfully accomplished either directly (by ingesting embryonated eggs or infective larvae) or indirectly (by ingestion of earthworms containing free or encysted gapeworm larvae they had obtained by feeding on contaminated soil). Life cycle and pathogenesis
In the preparasitic phase, third stage infective larvae (L3) develop inside the eggs at which time they may hatch. Earthworms serve as transport (paratenic) hosts.