And this maybe how they are able to find food to survive??
seehttp://www.umesci.maine.edu/ams/IB1181.htm#A1.7

Invertebrate Biology 118(1): 57-62
© 1999 American Microscopical Society, Inc.

An ascomycete commensal on the gills of Bathynerita naticoidea, the dominant
gastropod at Gulf of Mexico hydrocarbon seeps
Jill M. Zande
Department of Oceanography and Coastal Sciences, Louisiana State University,
Baton Rouge, LA 70803, USA
Abstract. The discovery of a fungal commensal on the gills of Bathynerita
naticoidea, the dominant gastropod at petroleum seep communities located
along the Gulf of Mexico upper continental slope (500-800 m), is reported.
Light and electron micrographs revealed filamentous fungi of the class
Ascomycetes and unidentified fungal bodies associated with the gill tissue
of each of the 7 freshly collected specimens of B. naticoidea examined.
Fungi were found attached to the surface of the gill cells, intercellularly,
within the gill blood spaces, enclosed in otherwise empty intracellular
vacuoles, and external but adjacent to the gill tissue. The exact nature of
this fungal association is unknown; the fungi may act to detoxify the
hydrocarbons and sulfide compounds of the seep environment, or may be
parasites that have infected the gill tissue. Although chemoautotrophic and
methanotrophic bacterial symbionts have been found previously within the
gills of deep-sea (2200-3000 m) hydrothermal vent gastropods, there was no
evidence of bacterial symbionts within the gills of B. naticoidea. This is
the first report of a fungal association within gastropods endemic to
hydrocarbon seep or hydrothermal vent communities