Scientists have identified a distinctive new species of seadragon, sea creatures looking similar to a seahorses but larger, and dubbed it the Ruby Seadragon for its bright red color.
Researchers at the Scripps Institution of Oceanography at the University of California, San Diego, found the new species among samples from the Western Australia Museum during studies to better understand and protect the two already known species of the exotic, delicate fish.
Seadragons have delicate appendages that look like leaves or vegetation that helps camouflage them among kelp and seagrass meadows off the southern and eastern coasts of Australia.
Scientists had thought there were just two species of the creatures, dubbed Leafy Seadragons and Weedy (or Common) Seadragons.
Analyzing DNA in the museum tissue samples, they found something unexpectedly different in one sample, and requested the complete specimen and photos taken when it was collected in Australia in 2007.
The creature's deep red color was "vastly different from the orange tint in leafy seadragons and the yellow and purple hues of common seadragons," the researchers reported in the journal Royal Society Open Science.
"It has been 150 years since the last seadragon was described and all this time we thought that there were only two species," says Nerida Wilson, a marine biologist with the Australian museum. "Suddenly, there is a third species! If we can overlook such a charismatic new species for so long, we definitely have many more exciting discoveries awaiting us in the oceans."
They have named the new species Phyllopteryx dewysea.
In common with seahorses, it is the male seadragon that carries the babies in a pouch until they are ready to emerge, explains Scripps graduate student Jodefin Stiller, who identified the original Ruby Seadragon museum sample, a male found to be carrying several dozen young seadragons.
"A CT (computer tomography) scan gave us 5,000 X-ray slices that we were able to assemble into a rotating 3-D model of the new seadragon," says Stiller. "We could then see several features of the skeleton that were distinct from the other two species, corroborating the genetic evidence."
Although only known from museum specimens -- only five in the world so far -- the researchers hope to mount an expedition to find and observe Ruby Seadragons in the wild.
The deep red coloring suggests Ruby Seadragons live in deeper waters than is home to Common and Leafy Seadragons, as the red shade would be absorbed at depth, leaving them looking dark and effectively camouflaged, scientists say.