Invasive snails target of USGS environmental DNA study

Jun 20, 2013
Invasive snails target of USGS environmental DNA study

(Phys.org) —Researchers at the University of Idaho and the U.S. Geological Survey have developed a way to identify New Zealand mudsnail infestations in their earliest stages – using only the small bits of DNA the snails shed in the water.

When New Zealand mudsnails move into a stream, they can wreak havoc on their new habitat. The tiny, invasive – barely larger than a sesame seed – multiply rapidly, pushing out . Salmon that pass through and eat the snails receive less nutrition than from their usual diet, resulting in smaller fish.

The team's work could help stream managers control mudsnail invasions before they cause significant damage to an ecosystem.

"For , we really want to catch them long, long before they get to the point of being obvious," said Caren Goldberg, a research scientist in UI's fish and wildlife department, who led the research project.

The team used a recently developed method of testing for a species' presence that analyzes environmental DNA, or eDNA, which is collected from skin and other cells an animal sheds into the environment. Their procedure compares DNA in the water to known mudsnail .

"eDNA monitoring for New Zealand mudsnails is a significant advance in aquatic invasive species management because eDNA is more sensitive, faster and often cheaper than traditional monitoring approaches," said USGS scientist Adam Sepulveda, the study's co-author. "Another benefit is that groups can become easily involved because collecting in the field requires simple equipment and minimal training."

"We can just take a water sample, filter it to catch the DNA and test it to see what species are in the water," Goldberg said.

Researchers in France proved in 2008 that eDNA could effectively show the presence of animals in wetland. In 2011, a UI-based team first demonstrated the same technique worked in , even though much of the DNA is diluted or washed downstream.

The New Zealand mudsnails added another layer of challenge because their hard shells may keep them from leaving behind large amounts of DNA, unlike fish or amphibians, which frequently shed scales or skin.

The team developed and tested their technique in UI's Laboratory for Ecological, Evolutionary and Conservation Genetics. They also tested it in southern Idaho's Portneuf River, in areas the mudsnail is known to live.

"It's a challenge to catch that fragment of DNA," Goldberg said. "We show we can do it, and reliably, too."

The researchers are now hoping to attract interest from stream and fish hatchery managers who could use the technique to track and prevent mudsnails, which are considered invasive species around the world and have been spreading across the West since the late 1980s.

The snails can be spread by watercraft or by tagging along with other species. Just one snail can start an infestation, because the species is parthenogenetic – the snails have the ability to reproduce asexually, giving birth to clones of themselves.

"We hope this test will help agencies to detect mudsnails early enough to protect systems from invasion," Goldberg said.

The study, "Environmental DNA as a new method for early detection of New Zealand mudsnails (Potamopyrgus antipodarum)," is available in the journal Freshwater Science, online at journal.freshwater-science.org.

Explore further: From dandruff to deep sea vents, an ecologically hyper-diverse fungus

add to favorites email to friend print save as pdf

Related Stories

New DNA test on roo poo identifies species

Jun 06, 2013

(Phys.org) —University of Adelaide researchers have developed a simple and cost-effective DNA test to identify kangaroo species from their droppings which will boost the ability to manage and conserve kangaroo populations.

Asian carp DNA not widespread in the Great Lakes

Apr 04, 2013

Scientists from the University of Notre Dame, The Nature Conservancy, and Central Michigan University presented their findings of Asian carp DNA throughout the Great Lakes in a study published in the Canadian Journal of Fi ...

New DNA-method tracks fish and whales in seawater

Aug 30, 2012

Danish researchers at University of Copenhagen lead the way for future monitoring of marine biodiversity and resources. By using DNA traces in seawater samples to keep track of fish and whales in the oceans. A half litre ...

Recommended for you

Of bees, mites, and viruses

12 hours ago

Honeybee colonies are dying at alarming rates worldwide. A variety of factors have been proposed to explain their decline, but the exact cause—and how bees can be saved—remains unclear. An article published on August ...

Genetically tracking farmed fish escaping into the wild

Aug 20, 2014

European sea product consumption is on the rise. With overfishing being a threat to the natural balance of the ocean, the alternative is to turn to aquaculture, the industrial production of fish and seafood. ...

France fights back Asian hornet invader

Aug 20, 2014

They slipped into southwest France 10 years ago in a pottery shipment from China and have since invaded more than half the country, which is fighting back with drones, poisoned rods and even chickens.

User comments : 0