Bioblitz survey finds false spider crab in Guam

Bioblitz Overview Photo 3
Above is an Elamena castanea, a false spider crab found in Guam during the first Bioblitz this year. Photo credit: Dr. Robert Lasley, PhD.
Among over a thousand species that were found during the University of Guam’s first Bioblitz is the Elamena castanea, a type of false spider crab.
 
While the Elamena castanea superficially looks like one, this species is not actually a spider crab and belongs to the Hymenosomatoidea superfamily which means they aren’t even related to true spider crabs.
 
Originally discovered in the Philippines, this is the first time that the species has been observed here in Guam even though the area has been sampled numerous times through the decades.
 
Since this discovery, several more crab specimens have been found on the reef flat behind the UOG Marine Lab.
 
“It shows you how much diversity there is out there,” said Robert Lasley, PhD, UOG Biorepository crustacea curator. “Elamena castanea specimens were collected under rocks or in seaweed in shallow depths – usually less than 1-2 meters.”
 
Lasley notes that even after the three-week biological survey, there are still hundreds, possibly even thousands, of marine species that remain undocumented in the waters off Guam.
 
“Honestly, though, we find new records all the time, often without noticing it,” he said. “It takes a lot of work at the microscope and digging through literature to confirm if something is a new species or new record.”
 
Along with the Elamena castanea, other findings included new records of different species of isopods, nudibranchs, nemerteans, gobies, and shrimps.
 
It has been estimated that between 10 to 15 percent of the specimens collected during the BioBlitz are either new records or entirely new species.
 
Since February, the Biorepository team has been developing and cataloging the specimens and uploading the specimen data to the Biorepository database.
 
Soon, they will be able to loan out specimens to researchers so that they can be further examined and new information can be reported.
 
The team is also planning future biological surveys with more targeted searches for specific organisms, using the information collected during this first Bioblitz.
 
In addition, they intend to organize surveys in other places throughout the region, such as Palau and the Marshall Islands.
 
Through these surveys, researchers will be able to learn more about what organisms call the vast ocean home, including the Elamena castanea, which will also help the community learn how to preserve and protect them.
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