File:Metagonimus LifeCycle.gif

Adults release fully embryonated eggs each with a fully-developed miracidium, and eggs are passed in the host’s feces. After ingestion by a suitable snail (first intermediate host), the eggs hatch and release miracidia which penetrate the snail’s intestine. Snails of the genus Semisulcospira are the most frequent intermediate host for Metagonimus yokogawai. The miracidia undergo several developmental stages in the snail, i.e. sporocysts , rediae , and cercariae . Many cercariae are produced from each redia. The cercariae are released from the snail and encyst as metacercariae in the tissues of a suitable fresh/brackish water fish (second intermediate host) . The definitive host becomes infected by ingesting undercooked or salted fish containing metacercariae . After ingestion, the metacercariae excyst, attach to the mucosa of the small intestine and mature into adults (measuring 1.0 mm to 2.5 mm by 0.4 mm to 0.75 mm) . In addition to humans, fish-eating mammals (e.g., cats and dogs) and birds can also be infected by M. yokogawai.

	This work is in the public domain in the United States because it is a work prepared by an officer or employee of the United States Government as part of that person’s official duties under the terms of Title 17, Chapter 1, Section 105 of the US Code. Note: This only applies to original works of the Federal Government and not to the work of any individual U.S. state, territory, commonwealth, county, municipality, or any other subdivision. This template also does not apply to postage stamp designs published by the United States Postal Service since 1978. (See § 313.6(C)(1) of Compendium of U.S. Copyright Office Practices). It also does not apply to certain US coins; see The US Mint Terms of Use.
This file has been identified as being free of known restrictions under copyright law, including all related and neighboring rights.

https://creativecommons.org/publicdomain/mark/1.0/PDMCreative Commons Public Domain Mark 1.0falsefalse