New Species

A new genus of giant protozoan, called a xenophyophore, has been found in the Nazare Canyon off the coast of Portugal.

Virtually bisecting the continental slope off the coast of Portugal, the Nazare Canyon is home to high concentrations of biomass ranging from cetaceans to fish to, in this case, giant protozoans. While on a HERMES (Hotspot Ecosystems Research on the Margins of European Seas) research expedition aboard the R.S.S. Discovery, members of the Continental Margins Ecosystems (COMARGE) project of the Census of Marine Life discovered specimens of a novel giant protozoan in sediment cores taken from depths around 3400 and 4300m. This protozoan, which is new to science but has not yet been formally described, is being classified as either a xenophyophore or a foraminiferan. It exhibits a unique test, or shell, that is comprised of bar-like structures that fuse to form mesh plates. This shell morphology has never before been reported in any other species of xenophyophore or foraminifera, and forms the basis of the suggestion that it is new to science.

Presumed to be a deposit feeder, this protozoan is one of a number of xenophyophore (or xenophyophore-like) species that inhabit the sediment surface in the deeper reaches of the Nazare Canyon, a rift that begins almost at the shoreline on the Portuguese coast and extends offshore about 150 miles into the Northeast Atlantic. The bathymetry of the canyon and the dynamic nature of the canyon's sediments, create an unusual environment that accumulates organic matter, adding to the biomass and species counts of the ecosystem. This sets it apart from typical continental slope environments and contributes positively to the biodiversity of the area. However, the canyon, its sediment flows, and downcurrents may also funnel and sequester pollutants into the depths from the nearshore area. With extensive research still necessary to fully understand this ecosystem, these novel protozoans are likely just one of many exciting discoveries that the Nazare Canyon will yield.



What: Discovery of a new species of xenophyophore (or foraminifera) in a subsea canyon off the coast of Portugal
Who: COMARGE/HERMES Scientists --> A. Gooday and A. Aranda da Silva
When: July 2005
Where: Nazare Canyon, Portuguese continental margin, Northeast Atlantic Ocean
How: Collected in sediment coring operations
Reference: No formal publication to date

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