نتایج جستجو برای: hatching of eggs
تعداد نتایج: 21165801 فیلتر نتایج به سال:
A total number of 88 fishes Thai pangas were conducted for induced spawning experiments. Among them, 30 mature Pangasius sutchi were conducted for the length-weight relationship, 25 matured females for the fecundity and 33 fishes (12 males and 21 females) for induced spawning experiments. The total-standard length relationship curve shows a straight line with a strong correlation (r = 0.986 and...
In order to reduce the adverse effects of sexual maturation on growth and survival of rainbow trout, production possibility of all-female triploid was investigated by means of early heat shock on eggs fertilized by masculinized male’s sperm. Fish ploidy level was determined by erythrocyte size measurement and confirmed by gill nucleolus (NORs) counting as well as chromosome number. Sexual ratio...
Pathogens can cause substantial mortality of amphibian eggs. If the timing of hatching is phenotypically plastic, embryos could escape from otherwise lethal infections by hatching early. We tested this with the arboreal eggs of red-eyed treefrogs, Agalychnis callidryas. A filamentous ascomycete (Dothideales: Phaeosphaeriaceae) was present on ;7% of egg clutches collected from a pond in the rain...
Crested penguins (genus Eudyptes) have a peculiar hatching pattern, with the first-laid egg (A-egg) hatching after the second-laid egg (B-egg) and chicks from A-eggs typically having a much lower survival probability. Maternal yolk androgens have been suggested to contribute to the competitive superiority of the B-chick in southern rockhopper penguins Eudyptes chrysocome, given their important ...
This experiment was carried out to examine the effect of temperature on egg incubation period, exogenous feeding onset, growth and survival of the zebra cichlid , Cichlasoma nigrofasciatum larvae with two replications. Experiment was conducted in four groups of brood stocks with Four temperatures with two replications 22-24 °C, 24-26 °C, 26-28 °C and 28-30 °C. After ovulation brood stocks were ...
Effects of culture filtrate of Verticillium chlamydosporium were evaluated on mortality of larvae and hatching of eggs of Meloidogyne javanica. Mortality of M. javanica larvae was found to be directly proportional to concentrations of culture filtrate of V. chlamydosporium and duration of exposure. Maximum mortality of larvae (65.5%) was observed in 100% concentration of culture filtrate after ...
The golden apple snail (Pomacea maculata Perry) is an invasive species that lays its eggs out of water but is otherwise aquatic. To investigate this behavior and potential management techniques, we conducted experiments to examine the physical effects of immersion and underwater egg predation on hatching success. Predation on submerged eggs by P. maculata adults reduced hatching success by ,99%...
prozac alters reproductive performance and filial cannibalism in male fighting fish, betta splendens
background: fluoxetine (prozactm) is one of the most popular antidepressant that can be released to aquatic systems via sewage-treatment effluents. it is suspected to provoke substantial effects in the aquatic environment. methods: in spawning tanks, specimens were exposed to concentrations of 0 and 0.54 µgl-1 fluoxetine from male introduction until the larvae had hatched. prior to spawning, ne...
in fish propagation and aquaculture industry, egg incubation period up to hatching is the most critical time. there is scarce information about events happening during this period for caspian kutum, which is a very economically important endemic fish in the caspian sea. morphological and histologial developmental changes of caspian kutum eggs and embryo up to hatching were investigated. develop...
The eggs of the stored grain pests, Tribolium castaneum (Herbst), T. confusum (Duval) (Coleoptera: Tenebrionidae) and Cadra cautella (Walker) (Lepidoptera; Pyralidae) belonging to three age groups, 1, 2, and 3 days-old, were exposed to ultraviolet (UV) radiation with 254nm wavelength (UV-C) for different durations to determine irradiation effects on egg-hatching and adult emergence. An increase...
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