title: A new classification of a preovulatory oocyte maturation stage suitable for the synchronization of ovulation in controlled reproduction of Eurasian perch Perca fluviatilis L.
abstract: To improve controlled reproduction of Eurasian perch Perca fluviatilis, the criteria for the evaluation of final oocyte maturation stages were revised. The new classification covers six preovulatory maturational stages (I -VI) from the end of vitellogenesis to germinal vesicle breakdown (GVBD) and was based on macroscopic changes of preovulatory oocytes (position of the germinal vesicle, GVBD, oil droplets coalescence). The observation was performed during out-of-season artificial reproduction with the use of a single hCG injection (500 IU/kg). The classification was subsequently verified with the controlled reproduction of wild female perch with the use of hormonal stimulation (500 IU hCG/kg of body weight at 12°C). The females were at different maturational stages and constituted respective experimental groups (I-VI). During the experiment, ovulation appeared to be considerably synchronized within particular groups. Statistical differences in latency time (time between hormonal treatment and ovulation) were found between experimental groups (mean latency time: 110, 92, 68, 49, 29 and 18 h in groups representing VI, V, IV, III, II and I stage of the proposed classification, respectively). The proposed classification and the results presented in the study allowed for effective synchronisation of ovulation. The use of our new oocyte maturation classification may positively influence the effectiveness of Eurasian perch production.
authors.affiliation: Department of Lake and River Fisheries, University of Warmia and Mazury, Poland. danielzarski@interia.pl
authors.forename: Daniel
authors.initials: D
authors.lastname: Zarski
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Bokor
authors.forename: László
authors.initials: L
authors.lastname: Kotrik
authors.forename: Béla
authors.initials: B
authors.lastname: Urbanyi
authors.forename: Akos
authors.initials: A
authors.lastname: Horváth
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Targońska
authors.forename: Sławomir
authors.initials: S
authors.lastname: Krejszeff
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Palińska
authors.forename: Dariusz
authors.initials: D
authors.lastname: Kucharczyk
mesh_terms: D000818:Animals; D017756:Aquaculture; D005260:Female; D008297:Male; D009865:Oocytes / Q000145:classification / Q000254:growth & development*; D010060:Ovulation; D010471:Perches / Q000502:physiology*