Screening of Saprolegniasis Preventive Drugs for Golden Trout (Oncorhynchus mykiss) Fertilized Eggs During Hatching

In order to screen the effective preventive drugs for saprolegniasis occurred during hatching of the fertilized eggs of golden trout, effects of two kinds of self-made Chinese herbal compounds（AB） and two kinds of chemical bactericides（peroxyacetic acid andhydrogen peroxide, CD） with three disinfection concentrations were compared in this study. The fertilized eggs of golden trout were randomly divided into 13 groups, each group with two parallels of 1 000 eggs. Drugs at high,medium and low concentration were respectively used to immerse the fertilized eggs35 min for disinfection once a day. The numbers of live and dead eggs were recorded each day before disinfection and the numbers of survival eyed eggs were counted in each experimental group after finishing the whole test. The results indicated that all of four kinds of drugs used here had a certain effect on prevention and control of saprolegniasis during hatching of fertilized eggs of golden trout, and also showed a correlation between the concentrations and effects. After the selection of several drugs, we found that group B-medium, C-medium and D-high exhibited the most remarkable effects on control of saprolegniasis. However, careful consideration should be given to chemical drugs residues and their potential hazard to the eyed eggs. Therefore, Chinese herbal compound B was suggested to be used for prevention and control of saprolegniasis to achieve the healthy aquaculture. And the concentration and operation time of Chinese herbal compound B should be strictly controlled when used in disinfection of fertilized eggs.

Differentiating between fertilized and unfertilized eggs prior to incubation based on oxygen flux measurement

One unresolved challenge in the egg industry is how to efficiently and non-invasively detect unfertilized eggs prior to incubation.This detection ability would not only significantly improve hatching rates and reduce costs but also conserve incubator space and prevent poor-quality embryos from contributing to the spread of infections.This study demonstrates a procedure for distinguishing between fertilized and unfertilized eggs prior to incubation by studying the respiratory differences between fertilized and unfertilized eggs using the Non-invasive Micro-test Technique(NMT).A customized micro-testing examination platform,NMT Egg Testing System(NMT-ETS)was constructed for the real-time monitoring of the intensity and rate of oxygen exchange between the egg and its external environment.The results from this study revealed that at room temperature,there is a significant difference in gas exchange rates between fertilized and unfertilized eggs.The results indicate that the oxygen flux of fertilized eggs exceed 20 pmol/(cm^(2)·s),whereas unfertilized eggs show a much lower oxygen flux.Based on the results,the NMT method can be used to effectively distinguish between fertilized and unfertilized chicken eggs.

Effects of Varying Temperature and Constant Temperature on Hatching Result of Fertilized Peacock Eggs

In order to investigate the effect of temperature on hatching result of fertilized peacock eggs, they were hatched under conditions of varying temperature and constant temperature respectively. The result shows that the hatching rate in the varying temperature treatment group （Group Ⅰ） is higher than that in the constant temperature treatment group （Group Ⅱ）. It suggests that the varying temperature treatment （high temperature in the early period, medium temperature in the middle period, slightly lower temperature in the late period, and slightly higher temperature in the hulling period） is in line with the optimum temperature variation in the hatching of fertilized peacock eggs, contributing the hatching of fertilized peacock eggs.

Transcriptome profiles of embryos before and after cleavage in Eriocheir sinensis:identification of developmental genes at the earliest stages

In crab, embryogenesis is a complicated developmental program marked by a series of critical events. RNA-Sequencing technology offers developmental biologists a way to identify many more developmental genes than ever before. Here, we present a comprehensive analysis of the transcriptomes of Eriocheir sinensis oosperms （Os） and embryos at the 2-4, cell stage （Cs）, which are separated by a cleavage event. Atotal of 18 923 unigenes were identified, and 403 genes matched with gene ontology （GO） terms related to developmental processes. In total, 432 differentially expressed genes （DEGs） were detected between the two stages. Nine DEGs were specifically expressed at only one stage. These DEGs may be relevant to stage-specific molecular events during development. A number of DEGs related to ＇hedgehog signaling pathway＇, ＇Wnt signaling pathway＇ ＇germplasm＇, ＇nervous system＇, ＇sensory perception＇ and ＇segment polarity＇ were identified as being up-regulated at the Cs stage. The results suggest that these embryonic developmental events begin before the early cleavage event in crabs, and that many of the genes expressed in the two transeriptomes might be maternal genes. Our study provides ample information for further research on the molecular mechanisms underlying crab development.

Effect of antikeratin microinjection on the embryonic development of Xenopus laevis

Anti-keratin monoclonal antibody AF5 was introduced into fertilized eggs of Xenopus laevis., and its effects on embryonic development were studied. Survival rate of the antikeratin-injected embryos was much lower (only 35.76% at gastrula) than that of the control (74.85% at gastrula), in which embryos were injected with mouse IgG. Most of survivors in the experimental series showed aberrant external appearance. On the other hand, in cleavage stage, ie 2-7 h after fertilization, immunohistochemi-cal staining of embryos showed that the experimental embryos were mostly keratin negative, while embryos of the control ones were keratin positive. When introducing this antikeratin into one cell of a 2-cell embryo, only the unin-jected half of the embryo continued its development while the other half could not develop at all. These results suggested that intact keratin cytoskeleton in early embryos is indispensable to the embryonic development of Xenopus laevis.

Embryonic and Postembryonic Development of Percocypris pingi pingi( Tchang)

This study aimed to investigate the morphological characteristics of Percocypris pingi pingi （Tchang） at the embryonic and postembryonic developmental periods and to demonstrate the early developmental stage of P. pingi pingi （Tchang）. According to the results, the fully mature eggs were spherical, orange-col- ored, sticky, 2.2 mm in diameter; the maximum outer diameter reached 3.2 -3.8 mm after absorbing water. When water temperature was （18 -＋ 0.5） ~C, the first cleavage occun~ at 2h 28 min post-fertilization; organs began to form at 45 h 23 min post-fertilization; larvae were hatched at 126 h 28 min post-fertilization. Newly hatched larvae exhibited a total length of 10.4 mm, with large and compressed yolk sacs. According to the morphological characteristics, the embryonic de- velopmental process of P. pingi pingi （Tchang） could be divided into seven continuous stages, including fertilized egg stage, cleavage stage, blastula stage, early gastrula stage, neurala stage, organ formation stage and hatching stage, which were further divided into 32 phases. When water temperature ranged from 18.8 ~C to 25.0 ~C, the whole developmental process of P. pingi pingi （Tchang） from larvae to juveniles lasted 93 d. According to the morphological and ecological charac- teristics, the pestembryonic developmental process of P. pingi pingi （Tchang） could be divided into three stages, including yolk-sac larva stage, late larva stage and junenile stage. This study laid solid foundation for .

Mathematical Model to Estimate Carbon Footprint for EEG Incubation

This work presents a performance comparison between several incubators models including CO2 and NH4 emission.A mathematical model for incubators carbon foot print was developed to estimate CO2 and NH4 emission.The program written by C++language including convert line.The modular structure of program consists of a main programme and series of independent subroutine:each one deals with a specific parameter of the required data.The computer programme has a wide range of applicability several values of size of the machine(NO.egg),Fertility(F),Heat production embryo(HPe),maximum CO2 level(CO2)m,CO2 level incoming air(CO2)I,RQ value(RQ)to estimate Heat production(HP),CO2 production,Ventilation(V),Ventilation of egg(Vegg)Input data:Enter size of the machine,Fertility(F),Heat production embryo(HPe),maximum CO2 level(CO2)m,CO2 level incoming air(CO2)I,RQ value(RQ)the results As the growth period passed from the first day of the twenty-first day,the amount of heat produced increased from 0.0001 to 0.35 w/egg,and ventilation from 0 to 352 m^3/hr as well as the amount of carbon dioxide produced from 0.0000158 to 0.04318 lit/hr/Mach.As the number of eggs increased from 5,000 to 30,000 eggs,each of the heat produced increased from 923.4 to 5540.4 kg/hr,the resulting carbon dioxide from 32 to 190 lit/hr/Mach,and ventilation from 9 to 54 m^3/hr.

A review of gynogenesis manipulation in aquatic animals

Gynogenesis is an established technique to generate all female type offspring and this technique has been successfully induced diploid gynogens progeny in aquatic animals of fishes and crustaceans.Monosex culture of all female shrimp and fishes were selected attribute to all female type offspring which have better size than male and help increase the market size and profitable.This article discusses on the protocol applied to produce gynogens progeny and the successful rate of gynogenesis production in fishes,molluscs and aquatic crustaceans of shrimps in general.Overall most of the UV length applied for irradiated the sperm were around 254-365 nm for(20-40 s),(20-80 s)and(5-8 s)for shrimps,254 nm,30 s for molluscs species and for fishes were around 254 nm for(1.5min)and(2-12 min)time of exposure respectively.For gynogenesis induction,the fertilized eggs were treated with cold shock,heat shock or cytochalasin-B for both shrimp and fishes gynogens technique.Fertilization rate was identified around 4.33%-19.67%in shrimp.Successful hatching rate was identified around 3.0%,14.9%-37.2%of gynogens offspring in shrimp and various percentages of hatching rates were identified from each species of fish gynogens.Overall,there is still low survival rate of gynogens produced using gynogenesis technique and further study should be carried out to improve the gynogens production.The discussed protocols serve as a guide lines for the gynogenesis technique application of all female monosex culture in the future.

Effects of delayed mating on the fecundity, fertility and longevity of females of diamondback moth, Plutella xylostella

The effects of delayed mating on the copulation duration, female fertility, fecundity, egg fertility, longevity and the number days alive after mating of females of diamondback moth （DBM）, Plutella xylostella, were studied. When male mating was delayed, the female fertility, fecundity, egg fertility, longevity and number days alive after mating of DBM decreased, and there was a negative correlation between the age of the moth with those variables except copulation duration. When female mating was delayed, the female fertility, fecundity, percent egg fertility and number days alive after mating of DBM also decreased, but the longevity increased, which also showed a negative relationship between the age of the moth with the variables except copulation duration and longevity. When both males and females delayed mating, the female fertility and fecundity decreased; egg fertility was affected marginally, and the longevity of females increased. The moth age was negatively correlated with those variables.