True crabs, false crabs and crabs twice described


Rob Lasley shows off the results of his crab-catching skills.
Image: Gary Cranitch.

 

19 May 2010
 
 
When is a crab truly a crab? Rob Lasley of the University of Singapore is studying brachyura, or true crabs, on the CReefs Ningaloo expedition.
 
 
 
Brachyura are an order of crustaceans that usually have a short tail and small abdomen hidden under the thorax. While some "wannabe" crabs take the name, such as hermit crabs and horseshoe crabs, these are not true crabs, but a different suborder of crustacean.
Rob's work is focusing on the xanthoid family of brachyura, specifically the subfamily chlorodiella. He expects to find new species of chlorodiella as well to sample extensively to improve the accuracy of the taxonomic record of these species. Rob will also take tissue samples of his specimens to be archived in a tissue library at the University of Singapore, and contribute samples to the Ocean Genome Legacy's Barcode of Life Database.
 
 
 
As a result of his work, Rob plans to reclassify some of the existing taxonomy of chlorodiella, removing two previously-named groups that have proved not to be distinct species, and adding four newly-discovered species.
 
According to Rob, "This happens quite often in taxonomy because many species were described a couple of hundred years ago. Often someone else comes along and thinks they have a new species but they haven't seen the old paperwork describing the original sample. When two different scientists describe the same species, those species are then called synonyms."
 
Rob says there is still a lot of work to be done in correctly classifying brachyuran. This work will be helped by efforts to archive and share information, such as scientists making their papers available on the internet, and the work of the University of Singapore tissue library and the Ocean Genome Legacy's Barcode of Life Database.
 
Projects that allow researchers to conduct fieldwork and to collaborate with other scientists, as on the CReefs expeditions, are also essential to improving the classification of species.