small elongate fishes of shallow northern seas; a long dorsal fin consists entirely of spines
small (2-4 inches) pugnacious mostly scaleless spiny-backed fishes of northern fresh and littoral waters having elaborate courtship; subjects of much research
small elongate fishes of shallow northern seas; a long dorsal fin consists entirely of spinessmall (2-4 inches) pugnacious mostly scaleless spiny-backed fishes of northern fresh and littoral waters having elaborate courtship; subjects of much research