The First Attempt to Artificially Reproduce the Endangered Cyprinid Lake Minnow Eupallasella Perenurus (Pallas)

The standard artificial reproduction technique with the use of Ovopel (GnRH analogue) was evaluated for the critically endangered cyprinid species in Poland, the lake minnow Eupallasella perenurus. Wild spawners were angled at the beginning of the spawning season. Only females with a condition coefficient value higher than the mean were included in the experiment and then stimulated with Ovopel. Group A (n = 20) was given standard treatment (0.2 pellet kg^–1 and 1.0 pellet kg^–1 after 12 h), whereas group B (n = 8) was treated with a single dose of 2.0 pellets kg^–1. After fertilisation with the dry method, the glutinous eggs attached to the bottom of flow-through aquaria were incubated at 17.1–18.4°C. Throughout incubation (85D°), dead eggs were removed and counted. The same was done with dead larvae, those with deformed bodies or those with empty alimentary tracts after 2 days of external feeding. Two injections of Ovopel resulted in a significantly (P 0.05) higher ovulation rate in comparison with the single dose (70 and 25% in groups A and B, respectively). The individual hatching rates were very high (98.4–100%), as was the share of good quality larvae (91.1 and 96.5% of stripped eggs in groups A and B, respectively). These results indicate that the standard propagation method used with commercially important cyprinid species can also be used to successfully breed E. perenurus.     

Investigation on fecundity, follicles and free embryo size of pond-reared pike (Esox lucius) of different age and size

The purpose of the present study is to investigate the gonadosomatic index (GSI %), the absolute and relative fecundity of one-year-old pike weighing over 400 g and at the same time to study the dependence between the egg size and the size, behavior and vitality of the free embryos obtained from one- and two-year-old spawners. The study involved two weight groups of females, differing in age and body weight and length—one-year-old (W = 514 g, SL = 36.1 cm) and two-year-old matured pike (W = 1454 g, SL = 49.3 cm). Ovary samples were fixed and egg follicles containing maturing oocytes counted and weight. The weight and length of the free embryos from semi-artificial spawning were measured. The results showed that, when raising this species under farmed conditions, more than 40% (in rarer cases 90%) of one-year-old pike females reached over 400 g and 35 cm (SL) and reached puberty. Absolute fecundity of 15,030 follicles (30 follicles per gram body weight) was observed; the GSI was nearly 15% and the follicle weight reached 3.7 mg. This data differs significantly from that obtained from the larger two-year-old fishes: absolute fecundity 41,363 follicles (28 follicles per gram body weight), GSI nearly 20%, follicle weight 5.8 mg. Results showed that the different follicle size determines the free-embryo size. A positive linear correlation was found between the egg follicle weight and the free-embryos weight (r = 0.7143). The free embryos obtain from the one- and two-year-old spawners differed significantly both in terms of their weight (7.13 mg against 10.61 mg) and total length (0.81 cm against 0.97 cm), the differences being 1.5- and 1.2-fold, respectively.     

亚致死浓度氰氟虫腙对小菜蛾生长发育及繁殖的影响

室内实验结果表明:氰氟虫腙对南昌和九江地区小菜蛾(Plutella xylostella)田间种群3龄幼虫的LC50分别为21.95和17.03 mg/L;用亚致死剂量(LC50)的氰氟虫腙处理小菜蛾种群后,处理代种群表现为化蛹率、蛹重、羽化率和繁殖力显著降低,蛹期明显延长,成虫寿命显著缩短,子代种群表现为卵孵化率和平均单雌产卵量显著下降,幼虫和蛹的历期显著延长。     

印度贝拉巴吉普伦淡水养殖场鲢鱼繁殖力的研究

作者检验了五十尾性成熟鲢鱼的卵巢。从统计学的角度,对鲢鱼的繁殖力同其总体长、体重和卵巢重量之间的关系进行了估计,发现三者关系均呈线形关系.同时还发现鲢鱼的繁殖力同体重的关系比同其总体长和卵巢重量的关系更为密切。     

大草蛉取食3种蚜虫对其生长发育和繁殖的影响

为了探讨大草蛉对不同蚜虫猎物的适应性,于2011-2012年,采用室内饲喂法和田间调查的方法研究桃粉蚜（Hyaloptera amygdali Blanchard）、绣线菊蚜（Aphis citricola Van der Goot）和牛蒡长管蚜［Uroleucon gobonis (Matsumura)］对大草蛉(Chrysopa septempunctata Wesmael)生长发育和繁殖的影响。结果表明:以桃粉蚜饲喂大草蛉时,其幼虫存死亡率最低、发育历期最短、蛹质量较高,成虫寿命最长,单雌平均产卵量最高;以绣线菊蚜饲喂大草蛉时,其幼虫死亡率较低,成虫寿命较长,单雌平均产卵量也较高,但幼虫发育历期最长,蛹质量最低;以牛蒡长管蚜饲喂大草蛉时,其幼虫发育历期较短,蛹质量最高,但幼虫死亡率最高,成虫寿命最短,单雌平均产卵量最低;田间调查的结果表明,大草蛉最喜欢在桃粉蚜危害的桃树嫩梢上产卵。综合评价,3种蚜虫中,桃粉蚜最适合大草蛉生长发育和繁殖。     

井上蛀果斑螟成虫饲养密度对其寿命及繁殖力的影响

为明确成虫饲养密度对井上蛀果斑螟Assara inouei Yamanaka寿命及繁殖的影响,在温度(25±1)℃、RH(70±10)%、光照15L∶9D、照度5 500lx条件下,以雌雄比1∶1共设5种成虫密度,依次为2、5、10、15和20对/产卵杯(840mL,直径10cm,高12cm),系统观察井上蛀果斑螟雌雄成虫寿命、产卵前期、产卵期、产卵量和卵孵化率等主要生物学特性。结果表明,成虫饲养密度对井上蛀果斑螟寿命和繁殖力有显著影响。饲养密度为2对时的产卵前期最长,产卵期最短;5、10、15和20对时的产卵前期无显著差异;10和15对时的产卵期显著高于其余3种密度。饲养密度为2对时的雌、雄成虫寿命最低,10对时的雌成虫寿命显著高于除5对外其余3种密度;5和10对时的雄成虫寿命显著高于其余3种密度。饲养密度为20对时的产卵高峰单雌日产卵量最少,10对时的产卵高峰单雌日产卵量显著高于除2对外的其余3种密度。饲养密度为20对时的平均单雌产卵量最少,5和10对时的平均单雌产卵量显著高于其余3种密度;10对时卵的孵化率显著高于其余4种密度。结果提示,井上蛀果斑螟成虫饲养密度过高或过低都显著降低其繁殖力,在840mL产卵杯空间下,以饲养密度10对最佳。     

青海湖裸鲤繁殖生物学研究

通过常规生物学测定、组织切片等手段,较详细的研究了青海湖裸鲤的繁殖生物学。卵母细胞从第3时相发育到第4时相基本同步,产后卵巢和精巢的组织学结构恢复到Ⅱ期。青海湖裸鲤为重复产卵类型,以Ⅳ期卵巢越冬,其卵巢1年只成熟1次,已达性成熟的个体并不是每年都进行繁殖活动。青海湖裸鲤性成熟迟、繁殖力低。每年5～7月,裸鲤洄游到沿湖各河流中繁殖,沙柳河、布哈河和黑马河3条河流为其主要产卵场。调查的繁殖群体总的性比(♂：♀)为1．66：1。总繁殖群体中,雄性个体最小体长130．0mm,体重28．0g,年龄4龄;雌性个体最小体长170．0mm,体重51．0g,年龄5龄。青海湖裸鲤性成熟群体的性体指标1年只有1个峰值,出现在繁殖盛期的6～7月。其平均成熟卵径为2．33mm,平均绝对繁殖力为4337．81粒,平均相对繁殖力为27．09粒／g。     

温度对大豆蚜生长发育和繁殖的影响

在5种不同温度条件下研究了大豆蚜有效积温、发育起点温度、繁殖力等生物学特性。结果表明,大豆蚜各虫态的发育历期随着温度的升高而显著缩短,若虫发育明显受到低温抑制。10℃下发育历期最长为22.08d,15、20、25、30℃分别为14.04,10.67,9.92和6.71d。相对低温同时也抑制大豆蚜繁殖能力,10℃下平均产仔量和日产仔量均为最小,分别为15.73头和1.23头/d。 20和25℃下大豆蚜繁殖力较强,平均每天产仔量分别为27.87和27.36头。通过直线回归分析,得出大豆蚜1龄若虫发育起点温度最高为2.0268℃,有效积温为38.4216日度,大豆蚜世代发育的起点温度为1.6587℃,有效积温为202.7879日度。     

香烟烟雾水溶液对雄果蝇生育力的影响

[目的]探讨香烟烟雾对雄果蝇生育力的影响。[方法]将野生型黑腹果蝇用含不同浓度香烟烟雾水溶液的培养基培养,然后使之与处女蝇交配,统计其蛹的发生量。[结果]随着香烟烟雾水溶液的浓度的增加,雄果蝇生育力降低。[结论]不同浓度香烟烟雾水溶液对雄果蝇的生育力有显著影响。     

光周期对梨小食心虫生长发育和生殖的影响

探讨光周期变化对梨小食心虫生长发育和生殖的影响,为科学预测梨小食心虫种群动态的季节变化提供理论依据。在温度(26±0.5)℃,RH(70±10)%人工气候箱中,研究15L∶9D、14L∶10D、13L∶11D、12L∶12D和11L∶13D 5个光周期对梨小食心虫生长发育和生殖的影响。不同光周期条件下梨小食心虫幼虫发育历期、成虫寿命和产卵量明显不同(P0.05),12L∶12D条件下幼虫发育历期最短、成虫寿命最长,产卵量最高;13L∶11D条件下幼虫发育历期最长;11L∶13D条件下成虫寿命最短,产卵量最低。但成虫产卵前期无显著差异(P0.05)。光周期变化对梨小食心虫的生长发育和生殖具有显著的影响。