Lundova Katsiaryna, Matousek Jan, Stejskal Vlastimil
Institute of Aquaculture and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Faculty of Fisheries and Protection of Waters, University of South Bohemia in České Budějovice, Na Sádkách 1780, 370 05 České Budějovice, Czech Republic.
Animals (Basel). 2021 Mar 5;11(3):692. doi: 10.3390/ani11030692.
The aim of the present study was to assess the effects of a prolonged photoperiod on growth rate and sexual maturation in brook trout The task of the experiment was to determine the most effective light regimen capable to minimizing the effects of puberty, including impairment of somatic growth and further general characteristics. In this regard, the studied fish were reared under three photoperiod regimens in which fish were exposed to 24 h continuous light alternating with 24 or 48 h under the ambient photoperiod or 48 h continuous light alternating with a 24 h ambient photoperiod. A control group was reared under the natural ambient photoperiod. Four-hundred and fifty fish with an average initial body weight of 101.3 ± 1.2 g were used for each experimental group (three replicates of each treatment plus control). A statistically lower growth rate showed control groups in both sexes. At the end of the study, control males had an average body weight of 226.6 ± 39.8 g and control females a body weight of 199.8 ± 12.2 g. At the same period, a significantly higher average body weight was found in groups reared 24 h under ambient photoperiod alternating with a 48 h continuous light regime (2CP:1AP) in both sexes (296.56 ± 62.5 g-males, and 239.9 ± 19.2 g-females, respectively). A significantly higher percentage of sexually mature fish was observed in the control group (80% of males and 29% of females, respectively). We found significantly fewer sexually mature females compared to males. The lowest survival was observed in group 2CP:1AP at 92%. It was concluded that regimen under which fish was exposed to 48 h of natural ambient photoperiod alternating with 24 h of constant light (1CP:2AP) lead to the successful delay of gonad development and onset of puberty and increased somatic growth in both sexes.
本研究的目的是评估延长光照周期对溪红点鲑生长速率和性成熟的影响。该实验的任务是确定最有效的光照方案，以尽量减少青春期的影响，包括体细胞生长受损及其他一般特征。在这方面，研究的鱼类在三种光照周期方案下饲养，即鱼类暴露于24小时连续光照，然后交替暴露于24或48小时的环境光照周期下，或48小时连续光照，然后交替暴露于24小时的环境光照周期下。对照组在自然环境光照周期下饲养。每个实验组使用450条平均初始体重为101.3±1.2克的鱼（每种处理三个重复组加对照组）。对照组两性的生长速率在统计学上较低。在研究结束时，对照雄性的平均体重为226.6±39.8克，对照雌性的体重为199.8±12.2克。同期，在24小时环境光照周期与48小时连续光照方案交替饲养的组（2CP:1AP）中，两性的平均体重显著更高（雄性为296.56±62.5克，雌性为239.9±19.2克）。对照组中观察到性成熟鱼类的百分比显著更高（雄性分别为80%，雌性为29%）。我们发现性成熟的雌性比雄性少得多。在2CP:1AP组中观察到的最低存活率为92%。得出的结论是，鱼类暴露于48小时自然环境光照周期与24小时恒定光照交替的方案（1CP:2AP）导致性腺发育成功延迟和青春期开始延迟，并使两性的体细胞生长增加。
