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A tale of two lamprey Martin River may hold key to deciphering mysteries about ancient fishRoxanna Thompson Northern News Services Published Thursday, July 19, 2012 Beginning on June 23, Claude Renaud, a research scientist with the Canadian Museum of Nature in Ottawa, his research assistant Noel Alfonso and a Russian colleague, Alexander Naseka, spent five days collecting lamprey larvae from the river located approximately 16 km from Fort Simpson. Renaud is hoping to determine if there are two species of lamprey in the territory.
Many biologists recognize only one species in the NWT, Yukon and Alaska, the Arctic lamprey, said Renaud. Arctic lamprey are parasitic and adults feed by attaching to other fish and feeding off of them.
The lamprey in the Martin River, however, are Alaskan brook. The river is the only known location in the territory where they exist.
Alaskan brook lamprey, unlike Arctic lamprey, are non-parasitic. The larvae anchor in the mud in the river leaving their heads sticking out against the current and filter feed on whatever drifts by, said Renaud. Adult Alaskan brook lamprey don't feed at all.
The question, said Renaud, is whether Alaskan brook lamprey are a distinct species or just a non-parasitic version of Arctic lamprey.
65 samples
To answer this question, Renaud, Alfonso and Naseka used electrofishing, which sends a mild electrical current through the water, to collect 65 Alaskan brook lamprey larvae from Martin River. The current forces the larvae out of the mud so they can then be collected with nets.
"It was a long slog," Renaud said.
The team also collected Arctic lamprey samples from Hay River and Slave River to provide a comparison.
This was the first time Renaud had been to the territory. Renaud said he was excited but also nervous because the only information about lamprey in the Martin River was 40 years old, dating from an impact study done in the 1960s.
"We weren't sure we'd be successful in collecting lampreys anywhere," he said.
With the specimens successfully in hand, Renaud will now spend approximately one year doing lab work. He will be looking at four different areas.
The samples from the Martin River will be compared to the Arctic lamprey larvae from Hay River, and Slave River. The specimens DNA and gene expression will also be analyzed.
There are two hypotheses to the differing natures of the lamprey samples. One suggests Arctic lamprey are parasitic and Alaskan brook lamprey are non-parasitic because they are two different species. The other surmises different proteins in the same species decides whether they are parasitic or not, Renaud said.
The research will also study the gonads, or sexual products, of the lamprey. Non-parasitic lamprey normally develop much larger eggs than parasitic varieties and Renaud wants to see if that is the case here.
Renaud will be writing one or more papers on the results of the lab work. Reports on the findings will be sent to communities in the Deh Cho.
While lampreys aren't everyone's cup of tea, Renaud said he has been interested in the primitive form of fish for more than 30 years.
"I find them really fascinating," he said. "There's a lot to learn."
Anyone who's now considering finding a new swimming location after learning there are lampreys in Martin River shouldn't be concerned, said Renaud.
"There's no problem because they are non-parasitic," he said. "It's unlikely that people will see them."
Anglers, however, might take a new interest in the river. Lamprey larvae make excellent bait for walleye, said Renaud.
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