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Has the cucumber changed its spots?

By: Prof Maria Byrne, Category: Science, Date: 09 Dec 2009

Recent research indicates the presence of a new species of sea cucumber at Lizard Island on the Great Barrier Reef.

 

Sea cucumber

Sven Uthicke  © Sven Uthicke

Story by Professor Maria Byrne, University of Sydney.

The Great Barrier Reef supports a great diversity of echinoderms. These marine invertebrates have been exceptionally well studied in the vicinity of Lizard Island in the northern part of the reef due to the presence of Lizard Island Research Station (LIRS), a facility of the Australian Museum. Concerted efforts to enrich the Museum’s collections of tropical echinoderms and other tropical species have focused on this region.

In the 1970's and '80's the Museum’s work in tropical echinoderms was championed by Museum Senior Fellow Dr Frank Rowe and subsequently by the Directors of LIRS, Drs Anne Hoggett and Lyle Vail.

As Australia's marine fauna is being revisited and revised with the assistance of molecular techniques, cryptic species − the presence of more than one species in a taxon name −are being discovered. Amazingly, some of these cryptic species are not obscure tiny creatures that have been overlooked, but large ones. This is because some of the largest animals are among the most difficult taxonomically, as is the case for tropical sea cucumbers, the sausage-shaped animals conspicuous in sandy habitats on coral reefs.

Recent research in collaboration with Sven Uthicke at the Australian Institute of Marine Science has indicated the presence of a previously undetected species of sea cucumber at Lizard Island.

Specimens collected near Lizard Island were, on appearance, considered to be a form of Bohadschia argus, a striking species broadly distributed in the Indo-Pacific. It is a conspicuous species because of the dramatic spots that cover its dorsal surface. However, molecular data showed that one of the bunch was different. We had to look more carefully at its spots. The devil is in the detail. Spots that is!

Considering the size of the animal, we thought it must have been seen, and hopefully collected, previously. To follow this up, the first port of call was the collections made by Frank Rowe from Lizard Island lagoon and held at the Australian Museum. It did not take long to find it. On examination of several specimens collected by Frank Rowe − there it was. It has been in the collections for 30 years. With this whole specimen to work with, its taxonomic features can be investigated in detail and a formal description and name given to this new Bohadschia species.

This shows just how valuable the Museum’s collections are when researchers want to review species identifications in the light of new information. Collections are not just records of the past – they are dynamic research tools that will continue to be used for expanding our knowledge of the world.