A University of Guelph study published Thursday said 25 percent of fish sold in Toronto and New York are mislabeled. The university study isn't based on fish tales, but DNA analysis.

According to the samples analyzed by the university, tuna was actually tilapia, halibut was hake, and red snapper was sold as lavender jobfish, Labrador redfish, perch or cod.

Robert Hanner, assistant professor of biology at the university, attributes the rampant mislabeling to lack of fish industry regulation. Hanner and co-author Eugene Wong tested 96 fish samples from groceries, markets and restaurants in the two cities.

Some of the mislabeling was not deliberate as species are known by their Latin scientific names, while local fisherman use their common names, which vary from one country to another. But in the process, buyers may be paying more, like in the case of tilapia, which costs only half of tuna's price.

Another area of concern is that the fish on the dinner table may already be an endangered species, like Atlantic halibut passed off as Alaskan halibut.

The commercial fishing industry has welcomed the DNA-testing technology to stop the mislabeling of fish. In the U.S., the National Fisheries Institute in Virginia established the Better Seafood Bureau last summer to check fish markets for mislabeling. The Bureau also opened a hotline where victims could report mislabeling.

The University of Guelph is at the forefront of a food labeling campaign. In 2005, philosophy professors launched a two-year study to find out if food labels should include data on genetically modified foods.