The Department of Biology, The University of New Mexico

Snail Tower, Lau Basin Back Arc Spreading Center, at ~ 2000 m

Dr. Fisher's research focuses on the physiology and ecology of symbiotic autotrophic marine microbes and their invertebrate hosts. These types of symbiotic associations are extremely important in the world's oceans, where symbiont dependent species are often the primary ecosystem-structuring organisms in both shallow tropical environments, such as coral reefs, and in the deep sea, where biomass may be limiting. The importance of the symbioses between algae and tropical invertebrates (such as corals, clams, and anemones) has long been recognized, and has been studied by biologists for more than 100 years. However, it wasn't until after the discovery of the deep-sea hydrothermal vents in 1977 that associations between chemoautotrophic bacteria and marine invertebrates were known (or for the most part even imagined). In these symbiotic associations, the bacterial symbionts oxidize reduced sulfur compounds as an energy source, fix carbon dioxide into organic carbon compounds (like green plants), and supply the bulk nutritional needs of their hosts. Although chemoautotrophic symbiosis were discovered first in the animals found around the rather exotic environments of deep-sea hydrothermal vents, we now realize that this type of association is wide-spread in the marine environment. In the last 10 years, chemoautotrophic symbionts have been found in hundreds of different animals inhabiting such diverse environments as mudflats, mangrove swamps, and sewage outflows, as well as in a variety of deep-sea cold-seep and hydrothermal vent sites. The unique mode of life represented by these animals has provided new insights into a variety of basic biological, geochemical and oceanographic phenomena. The recent realization of the pandemic distribution of these symbioses means that we can no longer view them as biological oddities found only in isolated, remote sites, but must realize their central role to many communities in all of the world's oceans.

All marine photographs courtesy of C.R. Fisher

Keynote Speaker

Dr. Charles Fisher
Professor of Biology,
Pennsylvania State University

“Chemoautotrophic Symbioses:
Making the Best of a Potentially Toxic Environment”

Hairy Snails, Lau Basin Back Arc Spreading Center,
at ~2000 m

Barnacles, Lau Basin Back Arc Spreading Center,
at ~2000 m