The Atlantic sport fish referred to in this crossword are the Tarpons (7 letters) and the Cero (4 letters). Tarpons are large, silvery fish that can grow up to 8 feet long and weigh up to 280 pounds. They are found in tropical and subtropical waters of the Atlantic Ocean, Caribbean Sea, and Gulf of Mexico. The Cero is a species of mackerel found in the western Atlantic Ocean from North Carolina to Brazil. It is a popular game fish and can reach up to 24 inches in length.