Reprodukce a intenzivní chov juvenilních ryb štiky obecné (Esox lucius L.)

Fish hatcheries do not always provide optimal conditions for controlled reproduction and production of high-quality juvenile in northern pike. This study was undertaken to optimize reproduction and intensive juvenile culture of northern pike (Esox lucius L.) under controlled conditions. The efficacy of traditional treatments for induction and synchronization of ovulation in northern pike (carp pituitary or ambient outdoor conditions) was compared to that of sGnRH-a at 50 and 100 ?g kg-1 with or without Freund´s incomplete adjuvant and dopamine inhibitor (metoclopramide, 8 mg kg-1). Ovulation was observed in females treated with carp pituitary (3 mg kg-1) and in those held in ambient conditions. Sperm motility parameters were compared in northern pike and sterlet (Acipenser ruthenus Brandt). Analysis was accomplished via high speed video microscopy complemented with CASA analysis. This work described recently developed methods of recognizing and quantifying sperm quality. The data obtained will lead to more accurate modeling of flagellum behavior during the motility period and provide a deeper understanding of basis of spermatozoa motility. The effect of water temperature on duration of embryo ontogenesis and hatching period; fertilization and development to the gastrula stage; hatching rates; and quality of larvae including larval size, development, and resistance to osmotic stress under controlled conditions for northern pike were investigated. Results indicated that the optimal temperature range for northern pike embryo development under controlled conditions is 6-10oC. Northern pike embryonic development hypothetically ceases at approximately 3.3 °C. In the certified methodology the basic aspects of controlled reproduction of northern pike was described and explained, including optimization of broodstock management. An objective of the certified methodology was to describe methods for producing high quality juveniles