Tuesday 8 October 2013

Five new species of deepwater Corals from the South American continental shelf.

Scleractinian Corals first appeared in the fossil record in the Middle Triassic; they are distinct from, but  believed to be related to the Rugose and Tabulate Corals of the Palaeozoic. All modern Corals are Scleractinians, as are all the known fossil species from the Mesozoic and Cenozoic. The Coral Reefs of the tropical oceans are generally considered to be among the most important of marine ecosystems, providing protection to storm battered tropical shores and forming biological hotspots. Less well known are the non reef-forming Corals, which do not form reefs or engage in other notable habitat-modifying behavior, but which are found throughout the world's seas, including in the freezing waters of the polar regions and the deep ocean seafloor.

In a paper published in the journal Zootaxa on 18 July 2013, Stephen Cairns of the Department of Invertebrate Zoology at the National Museum of Natural History in Washington DC, and Virginia Polonio of the Instituto Español de Oceanografía's Centro Oceanográfico de Gijón describe five new species of deepwater non reef-forming Coral from the deep South American continental shelf, as part of a wider study into deepwater Corals of the region. All the specimens were collected by the Instituto Español de Oceanografía's research vessel B/O Miguel Oliver in a series of expeditions between 2008 and 2010.

The first new species described is placed in the genus Caryophyllia, and is given the specific name kellerae in honour of Natalia Keller of the Shirshov Institute of Oceanography at the Russian Academy of SciencesCaryophyllia kellerae is a 35 mm solitary Coral living attached to a hard substrate. It is known from a single site in waters 310 m deep on the continental shelf off Cabo Blanco, as well as a fossil specimen from a borehole taken at 1161 m depth south of Cape Horn, though the age of this specimen is unknown.

Caryophyllia kellerae in lateral view. Cairns & Polonio (2013).

The known distribution of Caryophyllia kellerae. Cairns & Polonio (2013).

The second new species described is also placed in the genus  Caryophyllia, and is given the specific name coronula, meaning a small crown. Caryophyllia coronula is a 26 mm solitary Coral living attached to a hard substrate. It was found living on the continental slope off Golfo San Jorge, Argentina, at depths of 797–1553 m.

Caryophyllia coronula in lateral view. Cairns & Polonio (2013).

The known distribution of Caryophyllia coronula. Cairns & Polonio (2013).

The third new species described is placed in the genus Solenosmilia, and given the specific name australis, meaning southern. Solenosmilia australis is a branching colonial Coral reaching 60 mm in height. It was found at depths of 650–1620 m off central Argentina in the Atlantic and off Peninsula Taitao in Chile in the Pacific. 

Solenosmilia australis in lateral view. Cairns & Polonio (2013).

The known Atlantic distribution of Solenosmilia australis. Cairns & Polonio (2013).

The fourth new Coral species described is placed in the genus Flabellum and given the specific name cinctutum, meaning girdled or enclosed. Flabellum cinctutum is a subcylindrical solitary Coral living attached to a had substrate and reaching 43 mm high. It is found on the continental slope off central Argentina, at depths of 500–1626 m.

Specimens of Flabellum cinctutum. Cairns & Polonio (2013).

The known Atlantic distribution of Flabellum cinctutum. Cairns & Polonio (2013).

The final new species described is placed in the genus Javania, and given the specific name cristata, meaning crested or ridged. Javania cristata is a 35 mm solitary Coral living attached to a hard substrate, with distinctive enlarged ridges on its theca. It was found at depths of 461–1647 m, on the continental slope off central Argentina, and and on Burdwood Bank, which extends eastward from Cape Horn to the south of the Falkland Islands.

Javania cristata in lateral (left) and dorsal (right) views. Cairns & Polonio (2013).

The northern distribution of Javania cristata. Cairns & Polonio (2013).

See also Jellyfish force closure of Swedish nuclear power plantPunctatus emeiensis, not a Cnidarian after all? A new species of Hydrozoans from British ColumbiaThe mysterious ebb and flow of Jellyfish populations and The vanishing Corals of Pelorus Island.

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