Gamete management for artificial reproduction of northern pike Esox lucius (Linnaeus, 1758)

Eyeing and hatching rates with regard to sperm: egg ratio, the length of time eggs remain viable post-activation in water, and duration of storage time in testicular and stripped sperm were determined in northern pike Esox lucius. In a trial of seven sperm: egg ratios, we found 4 × 105 to be the minimum tested number of spermatozoa per egg to produce an acceptable hatching rate (66 ± 4%). To determine the period of time that eggs remain viable after activation, eggs were placed in hatchery water and fertilized at 0, 15, 30, 45, 60, 90, 120, 240, and 480 s post-activation. With elapsed time, the eyeing and hatching rates decreased significantly (P