What is "trophosome"

Trophosome \Troph"o*some\, n. [Gr. ? a feeder + -some body.] (Zo["o]l.) The nutritive zooids of a hydroid, collectively, as distinguished from the gonosome, or reproductive zooids.

n. 1 (context biology English) The group of nutritive zooids of a hydrozoan 2 (context biology English) The mass of chemolithoautotrophic bacteria in a pogonophoran that metabolizes sulfide

Trophosome is an organ that houses bacteria that completely nourish their host. Trophosomes are found in the coelomic cavity of the giant tube worm, Riftia pachyptila or in the symbiotic flatworms of the genus Paracatenula. Symbiotic bacteria in the trophosome oxidize sulfur found in the tube worm's environment and produce organic molecules that the hosts can use as an energy source. This process is known as chemosynthesis.