Scientists use 3-D scans to ID duckbilled fish species 40 years after it was caught – GeekWire

The duckbilled clingfish has a broad snout like a duck’s bill. (Kevin Conway and Glenn Moore)

After spending 40 years sitting in a museum jar, a toothy fish from the waters off Australia has been identified as a previously unknown species dubbed the duckbilled clingfish.

To document the species’ characteristics, researchers turned to technologies that weren’t widely available when the fish was caught in 1977: digitized X-ray scans and 3-D printing.

The fish tale was laid out last week in the journal Copeia.

It all began when Texas A&M fish taxonomist Kevin Conway and Glenn Moore, curator of fishes at the Western Australian Museum in Welshpool, were looking for interesting specimens in the museum’s collection.

There are more than 160 known species of clingfish, which are named for a disk on their bellies that they can use to cling onto wet, slimy surfaces. One of the finger-sized fish, preserved in a jar, caught the researchers’ attention because of its broad, duckbill-type snout and its rows of tiny conical teeth.

“This fish has characteristics we just haven’t seen before in other clingfish. It’s the teeth that really gave away the fact that this is a new species,” Conway said in a news release from the University of Washington.

Within a couple of hours, the pair found another specimen with similar features. But in order to document their discovery, the researchers had to present a detailed picture of the fish’s morphology, highlighting the distinctions of the species.

That usually calls for dissecting an intact fish, but because there were only two known specimens, the researchers ruled out that option. Instead, they turned to Adam Summers, a researcher at UW’s Friday Harbor Laboratories.

Summers, who specializes in clingfish, has taken on a project to scan and digitize every fish species in the world using computerized tomography (a.k.a. CT scanning).

When he put the duckbilled clingfish through the scanner, the resulting images brought out details that might have been missed during a manual dissection.

“This CT scan allowed us to take a completely noninvasive look at the entire skeleton of the fish, and it produced a gorgeous set of morphological photos that you couldn’t get from dissection,” Summers said. “It’s a testament to the importance of using these noninvasive methods of data collection.”

The scans were fed into a 3-D printer to produce larger-than-lifesize versions of the fish’s mouth and jaw structures. Based on the “digital dissection,” researchers estimate that the fish has 1,800 to 2,300 teeth, which is 10 times the number that other types of clingfish have.

A full-body scan shows the underside of the fish’s skeleton. (Kevin Conway and Adam Summers)

Conway noted that the teeth point backward, suggesting they might serve a gripping function. The only way to know that for sure, however, is to observe the fish in the wild – which has never been done.

Who knows? Now that the fish has been identified as a new species, known as Nettorhamphos radula, scientists just might keep a sharper eye out for the little duckbilled fish in the years to come.

After all, that’s basically how searchers were finally able to corner a mysterious 5-foot-long shipworm that gobbles up rotten-smelling hydrogen sulfide gas in a muddy Philippine lagoon. It’s hard to imagine the hunt for the duckbilled clingfish getting any ickier than that.