Malison et al, 1994


Malison, J.A and Porcarione, L.S. and Barry, T.P. and Kapuscinski, A.R. and Kayes, T.P. (1994) Endocrine and gonadal changes during the annual reproductive cycle of the freshwater teleost, Stizostedion vitreum. Fish. Phys. Biochem., pp. 473-484

Associated characteristics

Species Development state Trait Primary Data Secondary Data
Sander vitreus Female Oocyte development Group-synchronous ovarian developpement Group-synchronous
Sander vitreus Female Onset of oogenesis October [7.6% in November] ['October', 'November']
Sander vitreus Female Intensifying oogenesis activity January-February ['January', 'February']
Sander vitreus Female Maximum GSI value About 16-17 [April] 16.5 percent
Sander vitreus Female Oogenesis duration From October to April 7.0 months
Sander vitreus Female Resting period From May to October 7.0 months
Sander vitreus Male Onset of spermatogenesis September, GSI rise significantly and stay relatively constant until March ['March', 'September']
Sander vitreus Male Main spermatogenesis activity March [Also very important in September] ['March', 'September']
Sander vitreus Male Maximum GSI value Mean 3.2%, up to 3.7% [Prior to spawning, April] 3.2 percent
Sander vitreus Male Spermatogenesis duration From October until December 4.0 months
Sander vitreus Male Resting period <1% [From May through September] 1.0 months
Sander vitreus Spawning conditions Spawning season Walleye are one of the first species to spawn in the spring, shortly after ice break-up. Early to mid-April ['April', 'May', 'June']