活いけ締じめ

1. 1draining blood from a live fish (from above the gills and at the base of the tail) to keep it fresh Translated by Jiyomi
2. 2fasting fish for several days to preserve flavour and quality (and reduce mortality during transport)
3. 3killing fish in a fishtank (immediately before cooking) ; fish killed in a fishtank

Other writings and readings

JMdict entry 2651930. Source and licence.