A new lemaeopodid copepod gill parasite of the tarakihiCheilodactylus macropterusis described from two locations around New Zealand. It is distinguished from the other species ofAlellaon the basis of the armament of the first maxilla and the second antenna. Of 300 tarakihi collected from the Canterbury Bight, New Zealand, 21 fish, all less than 27 cm fork length and less than five years of age, carriedAlella tarakihin. sp. and a further three copepod specimens were obtained from 427 host fish from Tasman Bay.