Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
The gastropod Provanna laevis burrows into sulfidic mud in a collection container, (a) first digging a burrow, (b) then occupying the burrow with its carapace oriented downward, which exposes the population of attached sulfur bacteria to sulfidic conditions. (c) The head of the gastropod remains partially exposed above the sediment/water interface.
