Distribution and freshwater residence of Stokell's smelt, Stokellia anisodon (Stokell), in the South Island, New Zealand

Abstract

Stokell's smelt are restricted to some rivers on the east coast of the South Island, New Zealand, mainly in the Canterbury region. Migrations of Stokell's smelt into fresh water occur mostly from October to March. Analysis of samples taken from the Rakaia River at intervals during this period suggests that there are successive migrations of maturing fish, which continue to develop sexually during freshwater residence. The duration of residence could not be determined, but the presence of females containing relatively small eggs implies that some smeltremain in fresh water for weeks, or even months. Spawning occurs throughout the season, as ripe and spent fish were found in all the samples examined.

Keywords:

• Stokell's smelt
• Stokellia anisodon
• common smelt
• Retropinna retropinna
• spawning
• distribution
• New Zealand