A marlin is a fish from the family Istiophoridae ( includes about 10 species ) . It has an elongated body , a spear-like snout or bill , and a long , rigid dorsal fin which extends forward to form a crest .
Marlins , family Istiophoridae , are fish with an elongated body , a spear-like snout or bill , and a long rigid dorsal fin , which extends forward to form a crest .