LOS ANGELES (KABC) -- A man pleaded guilty on Wednesday to smuggling the world's largest freshwater fish into the United States.Isaac Zimerman, 66, used his now-defunct company, Hawthorne-based River Wonders LLC, to import a protected South American air-breathing species known as Arapaima gigas, prosecutors said.The fish can sometimes grow to 15 feet and weigh more than 200 pounds. They've been known to leap from the water to catch low-flying birds.Prosecutors said Zimerman, who used to live in West Hills, also attempted to smuggle 900 piranhas and dozens of river stingrays into the United States.In his plea agreement, Zimerman admitted possessing those fish in California, which were advertised for sale and shipped to customers in states outside of California.Zimerman was apparently selling baby fish that were approximately 10 inches long for $180 each, and shipping them overnight to their destinations in plastic bags.He was initially charged in 2009 and fled the country. Federal wildlife agents finally tracked him down in Mexico in March, and he was extricated to the U.S.Zimerman faces up to 10 years in federal prison at sentencing, which is set for Feb. 8, according to the U.S. Attorney's Office.