Biopapua / Off Feni Islands
14 October 2010
October 14, 2010
Ambitle and Babase are two islands that are small and isolated. As a result, their slopes should be relatively poor in terrigenous material and rich in hard substrates. We hope to find accumulations of the cnidarians Eric Pante is working on.
After making a bathymetric map of the outskirts of the islands during the night, we chose to start our work on the northern slope, which is not as steep and complex as the other sides of the islands.
This area is as promising as we hoped, and Eric rapidly spots some specimens of Chrysogorgia , a genus of gorgonian coral on which he works on for his dissertation.
Chrysogorgia is one of the most diversified gorgonian genera, and has a wide geographic and bathymetric distribution. We find Chrysogorgia in all major oceans, at all latitudes, from about 10 to 4000 m depth!
Eric is trying to clarify the systematics of this genus. He compares the morphological criteria used to separate species to the variability observed at a genetic level, and retraces the genealogical history of species.
One of his objectives is to understand which ecological and geographic factors explain the diversity found in this genus. Phylogenetic studies have shown that most species from the family to which Chrysogorgia belongs are found in the deep sea.
One of the questions Eric is trying to address is whether Chrysogorgia emerged once or multiple times from deep water to colonize shallower waters.
Aboard, Eric is also responsible for sampling other cnidarians. One of his colleagues, a specialist of sea anemones, is interested in our sampling.
To study sea anemones, and potentially describe new species, we need to relax them in a cool menthol bath. Once relaxed, sea anemones extend their tentacles and reveal more morphological characters.
Many sea anemones live in association with hermit crabs. Here is one, after being relaxed in menthol.
While participating on the “Cnidarian Tree of Life” project, Eric was able to contact many cnidarian taxonomists that are interested in our sampling. Hopefully, this collaboration will result enhance the value of the cnidarian specimens collected during our cruises.