Dragon out the truth
A MISNAMED seadragon found on Cottesloe Beach in 1919 is just one of four specimens of the newly discovered ruby seadragon identified by the WA Museum. The discovery hinged on a researcher’s request for more examples of another species and the resulting discovery of the new species of the elusive sea creature – related to seahorses – is the first in 150 years. WA Museum senior research scientist Nerida Wilson is now trying to organise a deep-sea expedition to find out more about the animal off WA’s coast.
MARINE scientists’ imaginations have been fired up by their discovery of the world’s first new seadragon in 150 years, using the WA Museum collection.
“As soon as we saw the DNA results we were excited,” museum senior research scientist Nerida Wilson, of Cottesloe, said.
A chance 2013 request by USAbased PhD student Josefin Stiller, who was double-checking for more examples of another seadragon, led to DNA results indicating a 2007 specimen trawled from 51m deep near Esperance was incorrectly named.
“When she DNA-sequenced it, she saw it was a seadragon, but very unlike a common seadragon,” Dr Wilson said.
A subsequent year-long investigation found three more incorrectly named seadragons in collections after they were caught between 51m and 72m deep several kilometres offshore, including one at the WA Museum that washed up on Cottesloe Beach in 1919.
Seadragons are related to seahorses and in the 19th century scientists named the endangered common and leafy seadragons, both about 20cm to 40cm when adults, that live in shallow reef and weedy areas such as Dutch Inn, South Cottesloe.
Dr Wilson said it appeared the new species, named the ruby seadragon, was more closely related to the common variety than the leafy.
It was a deepwater species that grew between 21cm and 24cm at depths greater than can be reached by recreational divers.
“What we know at best is that it’s found from Perth to Esperance and from three of the records that they are relatively deep and, who knows, could be found as far as Tasmania,” she said. More research is needed. “There are few records of the ruby seadragon range and the coast off Perth may have been affected by significant development in the past century, including the quality of the water and sea vegetation,” Dr Wilson said.
Attempts will now be made to raise funds for an expedition to research ruby seadragons, their body shape, including whether there are the appendages of its leafy cousin, food, habitat and range.
WA Museum's Dr Nerida Wilson with the ruby seadragon from 1919.
The ruby seadragon specimen trawled from Esperance in 2007.