Wednesday 19 December 2012

A new species of Sea Cucumber from the Kermadec Islands.

Sea Cucumbers (Holothuroidea) are a class of Echinoderms that have become elongated and worm-like, effectively becoming secondarily bilaterally symmetrical. Like all Echinoderms they have a calcareous exoskeleton, but this is greatly reduced, typically only occurring as ossicles within the epidermis. The muscle structure of Sea Cucumbers is instead supported by a layer of modified collegen that can be stiffened or relaxed at will, allowing for a more flexible body than that of other Echinoderms. 

In a paper published in the journal Zootaxa on 12 October 2012, Mark O'Loughlin of the Marine Biology Section at Museum Victoria and Didier Van den Spiegel of the Section invertebrés non-insects at the Musée royal de l’Afrique centrale in Tervuren, Belgium, describe a new species of Sea Cucumber from the Kermadec Islands; a New Zealand territory in the South Pacific, roughly half way between North Island and Tonga, discovered during the Kermadec Biodiscovery Expedition by RV Braveheart, which visited the islands from 9 to 29 of May 2011.

The new Cucumber is placed in the genus Chiridota and given the specific name kermadeca, meaning from the Kermadecs. It is a brown Sea Cucumber up to 20 mm in length and 5 mm in width, found on Stawell Shoal and at Boat Cove in the Kermadec Islands at depths of 10-24 m. It has 10 tentacles surrounding its mouth, rather than the 12 seen in other members of the genus Chiridota.

Chiridota kermadeca. O'Loughlin & Van den Spiegel (2012).

Dermal ossicles from Chiridota kermadeca. O'Loughlin & Van den Spiegel (2012).

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