Researchers have discovered previously unknown crab biodiversity hidden amongst corals.
The scientists discovered that Chlorodielline crabs, which are common and look very similar to other species within a group, are very difficult to tell apart by appearance alone.
Researchers found that crabs that don’t have overlapping ranges are virtually identical. However, those that do overlap will have a unique feature in the Gonopods. These are specialized appendages used for reproduction in many arthropods, including moths, millipedes and crustaceans.
According to Robert Lasley, the study lead author and current curator of crustacea at the University of Guam’s Biorepository:
“They all look the same, until you compare their gonopods, which are structurally complex and very species specific. They’re among the most abundant coral reef crustaceans, which makes them very important. They live in what are essentially apartment buildings made out of dead coral, and there are so many of them that any time you pick up a piece of reef rubble, they spill out.”
While Lasley determined that the species were related through DNA, explaining the wild variety in Gonopods is difficult. Figuring out the mystery of why exactly this divergence happens is a task for the future.
“What we can say is these crabs start genetically diverging in different geographic areas, and then the divergence of gonopods is an important piece of the speciation process that happens at the tail end of things.”
You can find the original research here.