Is the entree sitting in front of you $20-a-pound grouper, less pricey tilapia or perhaps cheap Asian catfish?Scientists at the University of South Florida's College of Marine Science are about to make it a lot easier — and quicker — to tell.A USF team has developed a handheld sensor capable of sniffing out fraudulent seafood claims, helping to ensure that consumers get what they pay for. As much as 30 percent of the seafood entering the United States is estimated to be mislabeled, bilking U.S. fishermen, the nation's seafood industry and consumers of up to an estimated $25 billion annually. It's a problem the bay area, in particular, struggled with amid investigations years ago by the Tampa Bay Times and others showing fake grouper being passed off as real to unwitting customers.Meet GrouperChek. A small device dubbed the QuadPyre attaches to a laptop and answers the question — Is this grouper? — within 45 minutes. The cost per test: about $30. Tests used to take days awaiting results and cost much more. The new method can be conducted anywhere, whether the fish in question is still aboard a ship, dockside, in warehouses, on supermarkets shelves or on restaurant plates. The test works on raw or cooked fish, even if covered with sauce. John Paul, USF Marine Sciences distinguished university professor and the lead scientist on GrouperChek, likens the device to the futuristic Star Trek "tricorder" used to detect life forms. The USF device tests seafood samples by identifying DNA markers unique to grouper. If the markers are found, the fish sample fluoresces, or glows. The handheld instrument is a portable version of a lab-based benchtop model developed a few years ago."Seafood authentication is a new market," Paul said Tuesday in his USF lab, where he demonstrated the device using a piece of grouper versus a visually identical piece of tilapia.Paul has spun off a start-up with backing from USF called PureMolecular LLC, which will operate in lab space in the Tampa Bay Research Institute near St. Petersburg's Carillon district. Paul, 62, serves as CEO and Robert Ulrich, 38 and a recent Ph.D microbiologist at USF, is chief technology officer. Their mission is to commercialize the GrouperChek device, priced at about $1,999 apiece and initially aimed at federal and state fish inspectors.Once GrouperChek is established, the scientists plan to add tests for other types of fish, including red snapper, tuna and halibut.They will debut their product at Seafood Expo North America, a major trade show, in Boston next month.Paul says the timing is good because of increased federal and state legislation to sharply increase fish inspections to deter fraud. A mere 0.02 percent of imported fish gets analyzed by inspectors."It's a big opportunity for quicker testing services," Paul said.Eventually, the scientists see fish testing becoming cheaper and faster, and even available as an app for a smartphone — if the consumer demands such a service.But first things first.The scientists picked grouper for their first test because of its local popularity and high price tag, because it is the third most economically valuable seafood product in Florida and because local quotas limit grouper catches. That means mass quantities of grouper are imported, creating greater opportunities for fraud.Identifying true grouper is complicated, Ulrich said, because the U.S. Food and Drug Administration allows 64 species of fish to be labeled as "grouper."GrouperChek has potential competition. In Ontario, Canada, a device created by InstantLabs at the University of Guelph uses DNA testing to verify the content of Atlantic blue crabs.At USF, the initial idea for proving fish is what it claims to be goes back over a dozen years when the College of Marine Science began deploying buoys in the Gulf of Mexico that could analyze the surrounding waters for the presence of red tide. The sensors used then are the basis for the device Paul demonstrated Tuesday.Such a device would have proved revolutionary nine years ago. That's when, after a rash of fake grouper problems, the Florida Attorney General's Office expanded its investigation to include the wholesalers who supplied it, including the nation's largest food distributor. Sysco Food Services-West Florida was ordered to turn over scores of documents, including records of all fish products bought and sold in 2006, results of every fish verification test for the past four years and the names of all former employees who handled imported fish in 2006. Sysco, based in Palmetto, supplied several restaurants with frozen "grouper'' imports that turned out to be cheaper species when tested last year by news outlets and the attorney general. The company said it did not know the fish was fake.That same year, this newspaper published DNA tests on grouper from 11 Tampa Bay restaurants. Six turned out to be other species, including a $23 "champagne-braised'' grouper that was actually tilapia.GrouperChek could put a big dent in such fish stories.Contact Robert Trigaux at [email protected] Follow @venturetampabay on Twitter.