ANCHOVIES, PILCHARDS, and SPRATS
An anchovy (family Engraulidae) and two species of true herring (family Clupeidae) occur in New Zealand waters. They move about in large shoals, often accompanied or pursued by other pelagic fish, such as mackerel, kahawai, or mullet. In some areas, at certain times of the year, they are exceedingly abundant, but their distributions and the factors controlling their migrations are still very incompletely known.
The anchovy, Engraulis australis (kokowhawha or korowhawha of the Maori), can be distinguished from the others by its large, undershot lower jaw. It grows to 3 or 4 in. in length and is blue above and silver below. It is more common in the north of New Zealand.
The pilchard, sardine, or Picton herring, Sardinia neopilchardus (mohimohi of the Maori), is 5–8 in. in length and silver in colour, slightly darker above. Occurring in vast schools, pilchards are taken as food by many other fish, including both surface and bottom-dwelling species, as well as by seabirds.
The sprat, Clupea antipodum (kupae of the Maori), is dark blue above, silver below, with the lower fins slightly yellowish, and has an average length of 3 in. Although very similar to the pilchard, the sprat can be distinguished by its deeper, narrower body, stronger spines on the belly, and the dorsal fin closer to the tail, inserted above and behind the ventral fins (the pilchard's dorsal fin is anterior to the ventrals).
Other fish sometimes confused with these three species and erroneously called “herrings” are the mullets (yellow eyed, and grey), young mackerel and kahawai, and the “whitebait” young of the freshwater inanga.
by Lawrence James Paul, B.SC., Fisheries Division, Marine Department, Wellington.