How do migrating daphnids cope with fish predation risk in the epilimnion under anoxic conditions in the hypolimnion?

Abstract

The vertical distribution of Daphnia in experimental tubes is influenced by fish kairomone concentration in the 'epilimnion' and oxygen conditions in the 'hypolimnion'. Daphnids trade off reduced predation mortality in a refuge against disadvantages due to unfavourable oxygen conditions.