Stokells smelt is the second of the two smelt species found in New Zealand. Although it superficially resembles the common smelt, it is sufficiently different, at least to biologists, to warrant a new generic name, Stokellia. This name honours G. Stokell, a biologist who collected and studied New Zealand’s freshwater fish for over 40 years, and who did much to identify and classify the species.
Stokells smelt has smaller scales than the common smelt, a feature that only an expert would recognise. The teeth, which are not a very obvious feature, are used to tell the two species apart. The small, fleshy, adipose fin can be used to distinguish smelt from galaxiids, however, smelt can be distinguished from the salmonids (which have an adipose fin) by the absence of a lateral line.
Found only on the east coast of the South Island between the Waiau and Waitaki Rivers, Stokells smelt is a strictly coastal species and is never found very far inland. In fact, this species probably spends most of its life in the marine environment. They enter fresh water to spawn in late spring and summer, and can be extremely abundant at times, providing a feast for the trout, kahawai, and sea birds that prey on the annual migrations. Stokells smelt grows to about 95 mm in length, but mature adults are typically 70–90 mm long.