1) Barbu 1) Fish 2) Percoid 3) Percoid fish 4) Percoidean 
• (n.) Any one of several species of fishes belonging to Polynemus and allied genera. They have numerous long pectoral filaments.
any of about 24 species of marine fishes of the family Polynemidae (order Perciformes), widely distributed along warm seashores, often over sand. ... [1 related articles]
Thread'fin` noun (Zoology) Any one of several species of fishes belonging to Polynemus and allied genera. They have numerous long pectoral filaments. 
USS Threadfin was an American Balao Class submarine of 1525 tons displacement launched in 1944. USS Threadfin was powered by diesel engines providing a top speed of 21 knots, carried a complement of 75 and was armed with one 4-inch gun, two 20 mm Oerlikon anti-aircraft guns; six 21 inch bow torpedo tubes and four 21 inch stern torpedo tubes.
[n] - mullet-like tropical marine fishes having pectoral fins with long threadlike rays
noun mullet-like tropical marine fishes having pectoral fins with long threadlike rays