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Mammalian egg activation at fertilization is triggered by a long-lasting series of increases in cytosolic Ca2+ concentration. These Ca2+ oscillations are due to the production of InsP3 within the egg and the subsequent release of Ca2+ from the endoplasmic reticulum into the cytosol. The generation of InsP3 is initiated by the diffusion of sperm-specific phospholipase Czeta1 (PLCζ) into the egg after gamete fusion. PLCζ enables a positive feedback loop of InsP3 production and Ca2+ release which then stimulates further InsP3 production. Most cytosolic Ca2+ increases in eggs at fertilization involve a fast Ca2+ wave; however, due to the limited diffusion of InsP3, this means that InsP3 must be generated from an intracellular source rather than at the plasma membrane. All mammalian eggs studied generated Ca2+ oscillations in response to PLCζ, but the sensitivity of eggs to PLCζ and to some other stimuli varies between species. This is illustrated by the finding that incubation in Sr2+ medium stimulates Ca2+ oscillations in mouse and rat eggs but not eggs from other mammalian species. This difference appears to be due to the sensitivity of the type 1 InsP3 receptor (IP3R1). I suggest that ATP production from mitochondria modulates the sensitivity of the IP3R1 in a manner that could account for the differential sensitivity of eggs to stimuli that generate Ca2+ oscillations. [ABSTRACT FROM AUTHOR]

In this study, the biochemical composition of wild and farm origin grayling eggs was compared, first, to evaluate the composition of fatty acids and protein content in grayling eggs for the first time, and second, to discover differences in biochemical composition between wild and farm origin eggs which is affected by broodstock feed. Farm origin grayling females were fed commercial trout starter feed, while wild origin females were feeding on food present in their natural environment. Fatty acid composition, protein content and colour were determined. Based on a principle component analysis (PCA) of the biochemical profile, farm and wild origin grayling eggs were clearly separated. Wild origin grayling eggs contained higher amount of SFA, but lower MUFA and PUFA than farm origin eggs. A considerable difference between wild and farm origin grayling eggs was observed also in essential fatty acids: C22:6 n-3 (DHA), C20:5 n-3 (EPA) and C20:4 n-6 (ARA), resulting in higher EPA/ARA and DHA/EPA ratio in farm origin eggs compared to wild origin eggs. Wild origin grayling eggs were characterised by higher protein content and were more intensely red-coloured than farm origin eggs, which were almost colourless. It could be concluded that the biochemical composition of farm origin eggs significantly differs from wild origin grayling eggs, which might have an influence on the embryonic development and hatching success of farm origin grayling. Therefore, the diet that has the greatest effect on egg composition needs to be optimised to meet the needs of the grayling broodstock and to improve the breeding efficiency of farm raised graylings. Biochemical composition of grayling eggs differs significantly between the two lifestyles (wild and farm origin). Differences in the proportion of essential fatty acids: DHA, EPA and ARA. Suboptimal EPA/ARA and DHA/EPA ratios in farm origin eggs. [ABSTRACT FROM AUTHOR]

Variation in sand composition at the individual beach level is an important factor for hatching success and hatchling phenotype that does not appear to have been previously investigated. We studied variation in intrabeach substrate composition in an important loggerhead turtle (Caretta caretta) nesting colony on the island of Maio, Cabo Verde, and examined its relationship with embryonic development success, hatchling phenotype, and hatchling vitality. Thirty-two nests from different females were studied under experimental conditions, controlling for beach position, depth, humidity, and temperature in a randomized block design. Two sand treatments corresponding to 2 types of sand from the same beach were used. While nesting females selected nesting sites indiscriminately between substrate types, their nests differed significantly in all variables measured for reproductive success (hatching success, hatchling size, and hatchling agility) between the 2 sand types. Therefore, the intrabeach observations of substrate phenotype of progeny found here could differentially affect offspring survival. The effects of choosing different nesting sites will generally act to spread the probability of selective pressures on embryos. Variation in reproductive success was due to differences between substrate types within the beach rather than the location of nests within the beach. The importance of determining sand types with the highest hatching success, even within the same beach, should be greatest in colonies or populations highly threatened with extinction, where the hatching success of each nest becomes of utmost importance. [ABSTRACT FROM AUTHOR]

With the exception of the savanna side-necked turtle (Podocnemis vogli) and the redheaded river turtle (Podocnemis erythrocephala), the species within the pleurodire genus Podocnemis have been relatively well-characterized in terms of their temperature-dependent sex determination (TSD) parameters. In this study, we incubated 4 nests of P. vogli (46 eggs) under controlled laboratory incubation conditions to determine whether this species also presents a TSD Ia pattern where males are produced at lower temperatures, characterize the constant temperature producing a 1:1 sex ratio (Tpiv), and document the transitional range of temperatures (TRT) that produces both sexes. The incubation temperatures employed were 29°, 31°, and 33°C (± 0.15°C). Our results were consistent with the conclusion that P. vogli exhibits a TSD Ia pattern, but it was not possible to document the Tpiv or the superior TRT, because the 29° and 31°C conditions produced all males and even the 33°C condition produced male-biased sex ratios, suggesting a high pivotal temperature for this species. We also documented maternal effects in initial size of the hatchlings, with the female that laid larger eggs producing hatchlings that were larger. Incubation periods of P. vogli were notably longer than those of its congeners incubated under comparable constant temperature and soil moisture conditions. In species of this genus, the TSD Ia pattern suggests that besides the threats these species face from overexploitation and habitat degradation, they also are highly vulnerable to the effects of global warming. [ABSTRACT FROM AUTHOR]

The present study was aimed to seek algorithms for prior identification of goose eggs unsuitable for incubation that, otherwise, turn into to hatching waste. These included infertile eggs and those in which the embryo did not survive by the hatch time. The algorithm development was based on egg parameter measurements taken before and during incubation. As a result, a complex of egg's geometrical parameters, i.e., its length, breadth and diameter at a point 1/4 of the length from the pointed end, were established as the best predictors and used for producing four novel indicators. The above parameters were incorporated into the first indicator called the Emergency Geometrical Index (EGI). Its use prior to incubation enabled to correctly identify 14–26% of eggs within the hatching waste category. The second indicator was the ratio of air cell volume to egg weight. The respective preincubation measurements enable to correctly identify ∼38% of unsuitable eggs. When combining the first two indicators, the third one was developed and called the Emergency Hatchability Index (EHI), with the correct identification rate being ∼65% of unsuitable eggs. Egg density (D) during incubation was proposed as the fourth promising indicator. This was expressed as the tangent of the slope for a trend line based on D data calculated for successive days of incubation. Collectively, the proposed four indicators and few other new methodological approaches used for their derivation will be instrumental in predicting hatchability of goose and other poultry eggs before incubation to reduce hatching waste. • Egg parameter measurements were used to define goose eggs suitable for incubation. • Four mathematical models were developed to predict correct identification of eggs. • The new indicators can be used to predict hatchability and reduce hatching waste. [ABSTRACT FROM AUTHOR]

Recent studies show that mosquito–microbiota interactions affects vector competence and fitness. We investigated if host antibodies modifying microbiota impact mosquito physiology. We focused on three prevalent bacteria (Acinetobacter, Pantoea , and Chryseobacterium), originally isolated from the Asian tiger mosquito Aedes albopictus. Our goal was to assess the impact of host antibodies on mosquito microbiota and life traits. Female mosquitoes were fed with blood from rabbits immunized with each bacterium or a mock vaccine. We compared various factors, including feeding behavior, survival rates, and reproductive success of the mosquitoes. Interestingly, mosquitoes fed with blood from a Chryseobacterium -immunized rabbit showed a significant increase in fecundity and egg-hatching rate. This outcome correlated with a decrease in the abundance of Chryseobacterium within the mosquito microbiota. While no significant changes were observed in the alpha and beta diversity indexes between the groups, our network analyses revealed an important finding. The antimicrobiota vaccines had a considerable impact on the bacterial community assembly. They reduced network robustness, and altered the hierarchical organization of nodes in the networks. Our findings provide the basis for the rational design of antimicrobiota vaccines to reduce mosquito fitness and potentially induce infection-refractory states in the microbiota to block pathogen transmission. [ABSTRACT FROM AUTHOR]

Habitat selection of Culicoides spp. (Diptera: Ceratopogonidae) is influenced by the physicochemical factors such as temperature, pH, salinity, moisture, conductivity, organic and inorganic compounds of substrates. These factors determine the life history traits of the vectors. We studied the influence of substrate salinity (0–40 parts per thousand, ppt) and pH (pH 1–13) on oviposition, egg hatching, larval survivability, and adult emergence of Culicoides peregrinus Kieffer under laboratory conditions. Most eggs (80.74%) were laid in 0 ppt and 95% in pH 7 but lowered with increased salinity and pH levels. It was observed that the females did not lay eggs in 30 ppt to 40 ppt salinity; pH 1 and pH 13 but interestingly up to 95% of the eggs were retained within the abdomen. Little effect of salinity and pH on egg hatching was observed up to 5 ppt and 10 ppt except at the extreme values of 40 ppt and pH 1, pH 13. Pupation did not occur in rearing plates with high salinities, 30 ppt and 40 ppt, although the few eggs hatched when exposed to such salinity. In low salinity (0 to 2 ppt), occurrence of adult emergence was more and then decreased with increasing salinity. Maximum emergence was seen when the rearing media was alkaline. This study deals with the suitability of breeding substrate of C. peregrinus when exposed to salinity and pH ranges. Our study suggests the ambient salinity and pH ranges to be maintained during laboratory rearing of this vector species. [ABSTRACT FROM AUTHOR]

Simple Summary: In nature, chicks under a broody hen hatch within a hatching window for a total of 8–10 h. However, in artificial incubation, this period is extended up to 48 h. This situation causes significant economic losses in the production industry. All behaviors performed by broody hens are imitated in artificial incubation, but only maternal sounds are absent. In this study, species-specific auditory stimulation (broody hen sound and embryo sound) was given to broiler embryos starting from the 444th and 468th hours of incubation. As a result, the hatching window decreased, chick quality improved, and the number of discarded chicks decreased in the auditory stimulation group starting from the 444th hour of incubation. The aim of this study is to expose broiler embryos to species-specific sounds from the 444th and 468th hours of incubation until the end of incubation and, thus, to determine the effects of these stimulations on their hatching characteristics, performance traits, developmental stability, and behavioral characteristics. Auditory stimulation sounds are a total of 5 min of recording consisting of sounds made by embryos during and after internal piping and response sounds made by the broody hen at that time. The auditory stimulation pattern was created as 5 min of recording and 5 min of silence for a total of 20 min of recording, and this sound pattern was played continuously with 65 dB sound intensity and 800 Hz sound frequency. A total of 750 Ross 308 broiler hatching eggs were equally divided into three groups (AS1: auditory stimulation from hour 444, AS2: sound stimulation from hour 468), and two stimulation groups and a control (silent) group were incubated in three homologous incubators. Due to auditory stimulation, the hatching window in embryos exposed to species-specific sounds beginning at the 444th hour of the incubation period was determined to be 28 h in this study. Auditory stimulation was late in the embryos exposed to species-specific sounds from the 468th hour of incubation, and the incubation windows in this group and the silent (control) group were determined to be 36 h and 40 h, respectively. The chicks that were exposed to early auditory stimulation during incubation exhibited a higher average Tona score (99.03) in comparison to the other groups (p < 0.05). Additionally, the number of chicks discarded was comparatively higher than the others (p < 0.05). Auditory stimulation during incubation had no effect on live weight, Gompertz growth curve parameters, feed conversion ratio, slaughter-carcass characteristics, behavioral traits, or developmental balance characteristics. Consequently, it was determined that the incubation window and the number of marketable chicks were both substantially impacted by the implementation of species-specific auditory stimulation. However, further research is required to ascertain the precise timing of this auditory stimulation. [ABSTRACT FROM AUTHOR]

Freshwater turtles are one of the most threatened vertebrate groups. Climate change is a major threat to these species, with impacts affecting all life‐history stages. There is currently a limited understanding of how changes in climate may alter the environmental triggers for hatching and emergence from the nests of freshwater turtle hatchlings. This precludes making predictions about how climate change may impact freshwater turtle recruitment success. The southwestern snake‐necked turtle (Chelodina oblonga) is endemic to south‐western Australia, a global biodiversity hotspot that has undergone severe climatic drying. Recruitment failure is thought to be occurring in many populations of the species. However, there is little understanding as to how environmental change may be influencing recruitment. This study aimed to: (1) determine the incubation duration and hatching and hatchling emergence success of C. oblonga, (2) determine if the species exhibits hatching or emergence synchrony and/or delayed emergence and (3) quantify the effects of temperature and rainfall on hatchling emergence. Using this information, the study assesses how climatic drying and warming may be impacting C. oblonga's early life‐history. Between 2018 and 2020 nest sites were monitored around a large urban wetland with weekly assessments of egg and hatchling status. Incubation duration and hatching and hatchling emergence success were calculated, and generalized linear models were built to determine how temperature and/or rainfall predicted emergence. Hatchlings either emerged shortly after hatching or overwintered in the nest, and both hatching and emergence were asynchronous. Both emergence periods were positively associated with temperature and rainfall. This study reveals that incubation duration, hatching success, hatchling emergence and survival are all likely to be impacted by recent and projected climate change, and especially drying. Warming and drying are predicted for many temperate regions globally, and it is therefore important that their impacts on the early life history of freshwater turtles be better understood. [ABSTRACT FROM AUTHOR]

The spotted lanternfly, Lycorma delicatula (White, 1845), is an invasive species in the United States. This pest causes damage to vineyards and has the potential to negatively affect other crops and industries. Information describing the seasonal timing of life stages can improve its management. In 2019 and 2020, spotted lanternfly seasonal activity was followed weekly from spring egg hatch to the first hard freeze. Weighted mean timing of activity for each nymphal instar, early adults, late adults, total adults, and egg mass deposition are presented for 2019 and 2020 on Acer rubrum and 2020 on Ailanthus altissima. Logistic equations describing the percentage completion of each activity period on these hosts were fitted using a start date of 1 January to calculate accumulated degree days (ADD). For the adult and egg mass deposition periods, we additionally used a biofix of the date adults were first observed to calculate ADD. ADD from 1 January adequately estimated the timing of nymphal instars but ADD from observation of the first adult better estimated the timing of adult activity and egg mass deposition. Late adult activity and egg mass deposition periods appeared to be influenced by another environmental cue, such as day length. Maps of season-long ADD show that spotted lanternflies are unlikely to reach adulthood in colder regions of the northeast United States, and therefore may not establish there. We also report a strong seasonal trend in sex ratio on A. rubrum, where the population shifted from over 80% male to over 80% female in October. [ABSTRACT FROM AUTHOR]

The copepod genus Oithona is among the most abundant mesozooplankton in both eutrophic and oligotrophic waters. This paper reports the individual and combined effect of temperature and pH on the development, reproduction success, and feeding preference of the tropical species Oithona rigida. Experiments were conducted at different temperature (28, 30, 31, and 32°C) and pH (7.7, 7.9, and 8.1) conditions. Effects on vital rates were observed for different developmental stages and adult males. Sex ratio varied from near 1:1 at 28°C to almost entirely female at 32°C. Egg production and hatching success were maximum at 30°C and pH at 7.9. O. rigida preferred the motile green alga Dunaliella salina in terms of ingestion rate, feed selectivity, and egg production across all the temperature and pH conditions. Long-term studies are needed to validate the adaptability of this species to a variety of climate impacts. [ABSTRACT FROM AUTHOR]

Introduction: Biological effects after a single prenatal exposure to ionizing radiation, reflecting significant heterogeneities in the responses in different species with respect to radiation type, dose, dose rate and time of exposure. Moreover, current knowledge and obtained results for poultry exposed to low dose ionizing radiation are inconsistent and almost lacking at present. The aim of this study was to determine the effect of low dose gamma radiation on protein profile in blood of chickens irradiated in ovo. Material and Methods: Fertilized chicken eggs in the experimental group were exposed to 0.3 Gy gamma radiation one hour before incubation, and control group was sham irradiated. Blood samples were taken on 1st, 3rd, 5th, 7th and 10th days of life. The plasma proteins fractions were separated by electrophoresis, while total protein and albumin levels were determined using the spectrophotometric method. Results: The obtained differences between control and experimental groups for total protein and albumin concentrations were statistically nonsignificant during our research. Total globulins were increased 10th day of chick's life due to an increase in alpha globulins (P < 0.05). In contrast, gamma globulins were decreased in one-day-old chickens exposed to ionizing radiation (P < 0.05). Conclusion: Our study indicates a significant effect of low-dose ionizing radiation on protein synthesis after in ovo exposure, although more research is needed to determine underlying molecular mechanisms triggered by low-dose gamma radiation. [ABSTRACT FROM AUTHOR]

Simple Summary: In a world filled with diverse ecosystems, understanding the behaviour of invasive species is crucial for maintaining balance and health. This study delves into the bioecology of the invasive oak lace bug in Europe, shedding light on its life cycle through a degree day-based model and presenting insights gathered from field-based life tables. Our research addresses key knowledge gaps, offering valuable information for effective pest control in forest ecosystems. By bridging the gap between scientific exploration and practical implications, we aim to empower the public with accessible knowledge on how to protect European forests and maintain the delicate equilibrium of natural environments. Corythucha arcuata, commonly known as the oak lace bug (OLB), is an insect species originally native to North America that has become an invasive species of significant concern in Europe. This invasive pest has been observed in various European countries, raising concerns about its impact on forest ecosystems. In 2015, it was first documented in Romania, further highlighting the need for research on its bioecology and life cycle. This study investigated the bioecology of the OLB in the southern region of Romania, focusing on its life cycle, development, and population dynamics. The results indicated that the OLB has three generations per year and overwinters in the adult stage in sheltered locations. Temperature significantly influenced the timing of egg hatching, nymph appearance, and adult development, with variation observed between generations. Additionally, a life table analysis provided insights into the population dynamics of the OLB in its natural environment, revealing variation in egg laying trends across generations. This research contributes to a better understanding of the OLB's bioecology and provides essential data for forest managers developing science-based management strategies to mitigate its impact. By elucidating the life cycle and development patterns of the OLB in southern Romania, this study aids in the development of predictive models and life tables tailored to the region. These findings empower forest managers with the knowledge needed to make informed decisions for effective OLB management, ultimately preserving the health of forest ecosystems. [ABSTRACT FROM AUTHOR]

Most studies of vertebrate breeding success have been unable to pinpoint the cause for a simple and almost universal pattern: its steady increase during an animal's lifetime. Yet potential causes of increased breeding success have profound implications for the evolution of reproductive behaviour. An age-related increase might come about through (1) higher breeding investment by older animals, (2) breeding improvement through learning, (3) better reproductive coordination between familiar mates or (4) accumulated benefits of site familiarity. We used mixed models to investigate age-related predictors of hatching and fledging success in a population of common loons, Gavia immer , that contained many known-age breeders and has been under continuous study for 30 years. Hatching success of breeding pairs increased between the female's first and second years on territory but did not increase with further female experience. In contrast, pair hatching success increased in proportion to the cube root of the males' residency on a territory, a pattern that persisted beyond 15 years. Hatching date was earlier for pairs that had spent at least 1 year together and in which the female was young but had spent at least one prior year on the territory. Fledging rate of hatched young was greater among pairs that nested early but decreased with female age, an apparent indication of female reproductive senescence. Overall, breeding pairs fledged more young when the breeding male had many years of experience on the territory and the breeding female had been on territory for at least 1 year and was of moderate age. Our findings highlight the persistent influence of both site familiarity and chronological age on reproductive fitness. • We examined attributes of male and female loons that affect reproductive success (RS). • Territory familiarity improved female RS only between the first and second years. • Age negatively affected RS in young and old females but made no difference in males. • Males showed increases in RS for over 15 years when they remained on familiar territory. • Mate familiarity had little impact on RS, but pairs with ≥1 year together nested earlier. [ABSTRACT FROM AUTHOR]

The effect of ethyl-4-bromophenyl carbamate on different Rhipicephalus microplus stages implanted in cattle was evaluated using the pen test with infestation chambers. Twelve steers were distributed into four groups (n = 3), each with four chambers (12 chambers per group), where approximately 1,000 R. microplus larvae were placed in each chamber. The chambers of the first group were sprayed with a solution of ethyl-4-bromophenyl carbamate (0.668 mg/mL) on day 2 post-infestation (PI) (exposed larvae). The chambers of the second group were sprayed with the same solution on day 8 PI (exposed nymphs), and the chambers of the third group were sprayed on day 16 PI (exposed adults) with the same solution. The chambers of the fourth group were used as controls. The percentages of engorged females, egg laying, egg production and egg hatching were evaluated in all groups. The percentage of cumulative reduction of hatched larvae was 98.3, 96.1 and 94.4% when larvae, nymph and adult stages were treated, respectively. The average cumulative reduction of hatched larvae, considering the three treated stages, was 96.3%, whereby the reproductive potential of this tick was drastically reduced. In conclusion, ethyl-4-bromophenyl carbamate acted as an ixodicide (lethal effect) when larval stages were sprayed and as a growth regulator when nymphal and adult stages were sprayed. The sum of these effects had a direct impact on the efficacy of the product in the pen test, and future studies will indicate the potential use of this product for tick control. [ABSTRACT FROM AUTHOR]

For some critically endangered species, conservation breeding is a vital steppingstone toward re‐establishing wild populations. The 'Alalā (Hawaiian crow, Corvus hawaiiensis), currently extinct in the wild, exists today only in a conservation breeding program, which, for many years, utilized successful hands‐on husbandry approaches such as separating and resocializing pairs, providing partially manmade nests, artificially incubating eggs, and puppet rearing nestlings. Yet, a top priority of any conservation breeding program is to retain natural behaviors essential to postrelease survival and reproduction, to achieve successful reintroduction and restoration to the wild. We describe how we are adapting 'Alalā husbandry techniques to strengthen pair bonds through full‐time socialization, enable pairs to build robust nests, encourage females to incubate eggs to hatch, and provide pairs and their offspring with vital parental rearing experiences. We discuss the use of standardized, data‐driven methods to objectively track our progress towards successful parental breeding and to select release candidates based on their likelihood to survive and breed in the wild. The information shared in this report can be applied to other conservation breeding programs, particularly those implementing or transitioning to husbandry techniques geared towards preparing species to thrive in the wild. Research highlights: Conservation breeding techniques for 'Alalā are designed to prepare individuals to thrive in the wild.A top priority is to maintain natural, species‐typical behaviors that are essential for post‐release survival and reproduction.Pairs are quantitatively monitored to assess performance and to identify release candidates. [ABSTRACT FROM AUTHOR]

A breeding female Two-banded Plover Charadrius falklandicus was observed incubating the eggs of a Magellanic Oystercatcher Haematopus leucopodus while the nest was unattended by the oystercatcher. The behaviour was likely triggered by the plover's nest becoming momentarily inaccessible, and so, being in incubation mode, the bird responded by incubating the nearest nest available. This is the first report of such behaviour while the oystercatcher was nearby, and the plover nest was still active and in sight. [ABSTRACT FROM AUTHOR]

Optimal dietary non-phytate phosphorus (NPP) is essential in poultry to maximise productive and reproductive performance, along with indices of egg and bone quality. This study aimed to establish the NPP requirements of egg-type duck breeders aged from 54 to 80 weeks on the following traits: egg production, egg incubation, egg quality, tibial characteristics, reproductive organ, plasma indices, and the expression of genes related to phosphorus absorption. Longyan duck breeders aged 54 weeks (n = 300) were randomly allotted to five treatments, each containing six replicates of 10 individually caged birds. Birds were fed corn-soybean meal-based diets containing 0.18, 0.25, 0.32, 0.38, and 0.45% NPP/kg for 27 weeks. The tested dietary NPP levels did not affect egg production or egg quality indices. The hatchling weight of ducklings increased (quadratic, P

Exposure to rising sublethal temperatures can affect development and somatic condition, and thereby Darwinian fitness. In the context of climate warming, these changes could have implications for population viability, but they can be subtle and consequently difficult to quantify. Using telomere length (TL) as a known biomarker of somatic condition in early life, we investigated the impact of pre‐hatching and nestling climate on six cohorts of wild nestling superb fairy wrens (Malurus cyaneus) in temperate south‐eastern Australia. Models incorporating only climate information from the nestling phase were best supported compared to those including the (pre‐)laying to incubation phase (previously shown to affect mass) or both phases combined. This implies that nestling TL is most sensitive to ambient climate in the nestling phase. The top model showed a negative relationship between early‐life TL and nestling mean daily minimum temperature when rainfall was low which gradually became positive with increasing rainfall. In addition, there was a positive relationship between TL and the frequency of hot days (daily maximum temperature ≥35°C), although these temperatures were rare and short‐term. Including other pre‐hatching and nestling period, climate variables (e.g., mean daily maximum temperature and mean diurnal temperature variability) did not improve the prediction of nestling TL. Overall, our results suggest that cooler nights when conditions are dry and short‐term temperature spikes above 35°C during development are conducive for somatic maintenance. While these findings indicate a potential pathway for climate warming to impact wildlife fitness, they emphasize the need to elucidate the mechanisms underlying these complex associations. [ABSTRACT FROM AUTHOR]

Environment-induced epigenetics are involved in diapause regulation, but the molecular mechanism that epigenetically couples nutrient metabolism to diapause regulation remains unclear. In this study, we paid special attention to the significant differences in the level of N6 -adenosine methylation (m6A) of dihydroxyacetone phosphate acyltransferase (DHAPAT) and phosphatidate phosphatase (PAP) genes in the lipid metabolism pathway of the bivoltine silkworm (Bombyx mori) strain Qiufeng developed from eggs incubated at a normal temperature (QFHT, diapause egg producer) compared to those from eggs incubated at a low temperature (QFLT, non-diapause egg producer). We knocked down DHAPAT in the pupal stage of the QFLT group, resulting in the non-diapause destined eggs becoming diapausing eggs. In the PAP knockdown group, the colour of the non-diapause destined eggs changed from light yellow to pink 3 days after oviposition, but they hatched as normal. Moreover, we validated that YTHDF3 binds to m6A-modified DHAPAT and PAP mRNAs to promote their stability and translation. These results suggest that RNA m6A methylation participates in the diapause regulation of silkworm by changing the expression levels of DHAPAT and PAP and reveal that m6A epigenetic modification can be combined with a lipid metabolism signal pathway to participate in the regulation of insect diapause traits, which provides a clearer image for exploring the physiological basis of insect diapause. [ABSTRACT FROM AUTHOR]

Personality varies among individuals and is influenced by the environment. Here, we tested the hypothesis that egg incubation temperature had carry-over effects on swimming activity of juvenile brown trout, Salmo trutta. Eggs from different crosses involving anadromous and lacustrine-adfluvial parents were incubated under two temperature regimes, unheated (cold) or heated c. 2.5 °C above ambient temperature (warm), until first exogenous feeding. In the laboratory, we used open-field tests to quantify swimming activity in a new environment, and mirror-image tests to measure time spent swimming and resting motionless near a mirror, measures often used as proxies for aggression. These tests were conducted for two cohorts, with one tested in June 2018 and the other in June and August 2019, enabling us to test for repeatability and if differences persisted over the summer. In June, when adjusting for differences in body size between cold- and warm-incubated trout, we found that juvenile trout incubated as embryos at cold temperatures showed more swimming activity and took less time to initiate swimming for their size than those incubated in warm water. There were also body size and year effects but no effects of parental cross. For August, none of the incubation temperature effects observed in June persisted, but cold-incubated trout spent a larger proportion of their time motionless near the mirror than warm-incubated trout and there was a general body size effect on time to initiate swimming. The lack of any persistent effects of incubation temperature between June and August suggests that the effect is ephemeral. Notwithstanding, these results support the hypothesis that incubation temperature has short-term effects on activity of juvenile of brown trout during their first summer. Significance Statement: We studied the effect of embryonic temperature on juvenile fish behavior, focusing on swimming activity under different conditions. Brown trout eggs were incubated under two temperature regimes, cold and warm. We show that juvenile trout originating from cold conditions as embryos spent a greater proportion of time swimming and less time to initiate swimming than trout originating from warm conditions. These effects were present in June but not August, which suggests that the effect is short-lived, and occurs during the first summer when mortality of juveniles is high. The duration of the effects needs further study as our previous studies have shown persistent embryonic temperature effects on metabolism, body shape, reproductive potential and emigration of subsequent life stages of salmonids. These results also have bearing on ongoing climate change as even small differences in embryonic temperature may have ecological consequences for subsequent life stages. [ABSTRACT FROM AUTHOR]

The black stork is an endangered species in many countries, due to its low adaptability to environmental changes and its sensitivity to anthropogenic disturbances. In Italy, the most recent report on the species' nesting sites lists only 36 pairs, of which 16 are in Basilicata, 7 are in Calabria, 4 are in Piedmont and Molise and 1 is in Campania. This study focuses for the first time on the behavior of a Ciconia nigra pair in the Basilicata region, where the species nests exclusively on cliffs rather than in trees, as is more frequent elsewhere. The video recordings were used to observe the species during the pre- and post-hatching periods and to refer to the 2012 nesting season, as in that year, the video recordings covered the entire reproductive period. In the pre-hatching phase, the activity for which most time is spent is brooding, which lasts on average 43′ in the morning and in evening and more than 49′ at midday. In the post-hatching phase, a large part of the recording period is spent on activities related to parental care. There were no moments of inactivity during this phase, the parents were frequently observed setting up the nest and preening themselves, while they were rarely seen in a huddled position. The alert activity was also very frequent, especially at midday. Our study has shown that the black stork, a shy and cautious species, may return to nest in increasing numbers given the development of the promising Lucanian nucleus, if attention is paid to the habitat quality and feeding areas, where human activities should be avoided unless absolutely necessary. [ABSTRACT FROM AUTHOR]

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Trehalase inhibitors prevent trehalase from breaking down trehalose to provide energy. Chitinase inhibitors inhibit chitinase activity affecting insect growth and development. This is an important tool for the investigation of regulation of trehalose metabolism and chitin metabolism in insect reproduction. There are few studies on trehalase or chitinase inhibitors' regulation of insect reproduction. In this study, ZK-PI-5 and ZK-PI-9 were shown to have a significant inhibitory effect on the trehalase, and ZK-PI-9 significantly inhibited chitinase activity in female pupae. We investigated the reproduction regulation of Spodoptera frugiperda using these new inhibitors and evaluated their potential as new insecticides. Compounds ZK-PI-5 and ZK-PI-9 were injected into the female pupae, and the control group was injected with solvent (2% DMSO). The results showed that the emergence failure rate for pupae treated with inhibitors increased dramatically and aberrant phenotypes such as difficulty in wings spreading occurred. The oviposition period and longevity of female adults in the treated group were significantly shorter than those in the control group, and the ovaries developed more slowly and shrank earlier. The egg hatching rate was significantly reduced by treatment with the inhibitor. These results showed that the two new compounds had a significant impact on the physiological indicators related to reproduction of S. frugiperda , and have pest control potential. This study investigated the effect of trehalase and chitin inhibitors on insect reproduction and should promote the development of green and efficient insecticides. [ABSTRACT FROM AUTHOR]

BACKGROUND: Light stimulation at a specific wavelength triggers various responses in insects and can be used for pest control. To develop efficient and ecofriendly photophysical pest control methods, the effects of green light on locomotion, growth (molting and eclosion) and reproduction in Nilaparvata lugens (Stål) (BPH), a major rice pest, were studied. Transcriptomics and transmission electron microscopy (TEM) were used to investigate the mechanisms involved. RESULTS: BPH adults showed disrupted daily locomotion patterns following green light treatment at night and exhibited abnormal locomotion peaks. Total 6‐day locomotion of brachypterous adults was significantly greater than in the control group. The durations of growth stages 1–4 were all shorter under green light treatment than in the control, whereas the time from fourth molting to eclosion (stage 5) was significantly longer. When BPH adults under green light treatment began laying eggs, the egg hatching ratio (36.69%) was significantly lower than in the control (47.49%). Moreover, in contrast to the control, BPH molting and eclosion events tended to happen more at night. Transcriptome analysis proved that green light significantly affected the expression of genes involved in cuticular proteins, chitin deacetylase and chitinase, which are related to cuticular development. TEM observations confirmed abnormal cuticular development in nymph and adult BPHs (endocuticle, exocuticle and pore canals) under green light treatment. CONCLUSION: Green light treatment at night notably affected locomotion, growth and reproduction in BPH, thus providing a novel idea for controlling this pest. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

BACKGROUND: Mating and oviposition are essential and closely coordinated events in the reproduction of moths. Although tyramine, a biogenic amine, can affect insect reproduction by binding its receptors, the specific regulatory mechanism has not yet been fully elucidated. RESULTS: Plutella xylostella mutant with tyramine receptor 1 (TAR1) knockout (homozygous mutant with 7‐bp deletion, Mut7) was developed by the CRISPR/Cas9 system to investigate the effect of TAR1 knockout on the reproduction of the moth. Compared with wild‐type (WT), the egg yield of Mut7 female (Mut7F) was significantly lower, no significant difference was observed in the egg size and hatching ratio between the groups. Further analysis showed that TAR1 knockout adversely affected ovary development, characterized by shorter ovarioles and fewer mature oocyte. Additionally, TAR1 knockout significantly reduced the occurrence of mating, resulting in a decrease in egg yield in Mut7F. The amounts of sex pheromones were quantified using gas chromatography–mass spectrometry. Results showed that the amounts of sex pheromone released by Mut7F were significantly lower before mating. Correspondingly, the messenger RNA (mRNA) levels of sex pheromone biosynthesis enzymes, including acetyl‐CoA carboxylase (ACC) and desaturase (DES), were significantly lower in the Mut7F pheromone gland. The decreased sex pheromone biosynthesis in Mut7F, especially before re‐mating, may be related to the underexpression of pheromone biosynthesis‐activated neuropeptide (PBAN). CONCLUSION: Overall, this study investigated the effect of PxTAR1 on oviposition and mating of P. xylostella. We report for the first time that TAR1 knockout could reduce the sex pheromone biosynthesis. These findings provide insights for developing a novel integrated pest control strategy based on mating interference. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The fast-growing sector of insects for food and feed stimulates researchers and the industry to explore uncharted territories, such as insect breeding, to improve economically important insect fitness traits. The yellow mealworm, Tenebrio molitor L., is one of the most thoroughly studied insect species as food and feed. However, data on mating compatibility and the effect of cross-breeding between different strains on the performance and fitness of the hybrids are scarce. In the present study, we comparatively evaluated the mating compatibility between two T. molitor inbred strains (Greek and Italian) and their outbred strains, i.e., Italian (♀)-Greek (♂) and Greek (♀)-Italian (♂), as well as the performance of their hybrid offspring. Based on the results, there is good mating compatibility among adults of the strains tested. Offspring performance, quantified as larval survival and final larval weight, followed a similar pattern among the crossings examined. Even though differences were insignificant, the outbreeding of females of the Italian strain resulted in a higher cumulative number of eggs and hatching rate and higher offspring weight. The present study sheds light on the mating compatibility of different T. molitor strains and their hybrids' economically important life table characteristics to take the mass production of insects one step further. [ABSTRACT FROM AUTHOR]

The bacterial microbiota promotes the life cycle of the intestine-dwelling whipworm Trichuris by mediating hatching of parasite eggs ingested by the mammalian host. Despite the enormous disease burden associated with Trichuris colonization, the mechanisms underlying this transkingdom interaction have been obscure. Here, we used a multiscale microscopy approach to define the structural events associated with bacteria-mediated hatching of eggs for the murine model parasite Trichuris muris. Through the combination of scanning electron microscopy (SEM) and serial block face SEM (SBFSEM), we visualized the outer surface morphology of the shell and generated 3D structures of the egg and larva during the hatching process. These images revealed that exposure to hatching-inducing bacteria catalyzed asymmetric degradation of the polar plugs prior to exit by the larva. Unrelated bacteria induced similar loss of electron density and dissolution of the structural integrity of the plugs. Egg hatching was most efficient when high densities of bacteria were bound to the poles. Consistent with the ability of taxonomically distant bacteria to induce hatching, additional results suggest chitinase released from larva within the eggs degrade the plugs from the inside instead of enzymes produced by bacteria in the external environment. These findings define at ultrastructure resolution the evolutionary adaptation of a parasite for the microbe-rich environment of the mammalian gut. Author summary: Trichuris, or whipworms, are intestinal parasites estimated to affect a billion individuals worldwide. High worm burden is associated with the tropical disease known as trichuriasis. Available chemotherapeutic agents have limited efficacy. Following ingestion by the mammalian host, Trichuris eggs hatch in a manner dependent on bacteria that are part of the gut microbiota, representing a symbiotic relationship that is a potential point of vulnerability in the parasite lifecycle. In this study, we examined how bacteria mediate Trichuris egg hatching using advanced imaging techniques. 3D reconstruction of eggs exposed to bacteria revealed the detailed structural changes that occur at the polar plugs from which larvae exit. We show that the polar plugs undergo asymmetric disintegration, which is associated with the density of attached bacteria and release of the shell degrading enzyme chitinase. These findings offer a clearer picture of how Trichuris has evolved to adapt to the bacteria-rich environment of the host. [ABSTRACT FROM AUTHOR]

Fishes of the jawfish family Opistognathidae are cryptobenthic and distributed in subtropical seas, and new species are still being reported. Opistognathus spp. live alone in burrows and males orally brood their egg clutches. The life cycle of jawfish, including their reproductive behaviour, is poorly understood. Here we describe the natural reproduction and embryonic development of Opistognathus iyonis in Yamaguchi, Japan, based on underwater surveys for 3 years. Spawning was observed as female jawfish came into the male's burrow ~30 min before sunrise. The jawfish had a mean number of 4.4 egg clutches in the burrow through 48.2 days, and the egg took 12 days to hatching. The mean temperature for developmental days was 20.8°C. The mean and cumulative water temperature during development significantly correlated with the number of developmental days. During egg development, male jawfish took care of eggs by holding them for part of the time in their mouths. Hatching was observed ~20 min after sunset. When hatching occurred orally, eggs were pushed out and back repeatedly using the lower jaw; consequently, the egg clutches were let out in an upward direction. To our best knowledge, this is the first report of the reproductive behaviour of O. iyonis in the natural environment in the same area for several years. [ABSTRACT FROM AUTHOR]

Phenotypic plasticity is an important avenue by which organisms may persist in the face of rapid environmental change. Environmental cues experienced by the mother can also influence the phenotype of offspring, a form of plasticity called maternal effects. Maternal effects can adaptively prepare offspring for the environmental conditions they will likely experience; however, their ability to buffer offspring against environmental stressors as embryos is understudied. Using captive zebra finches, we performed a maternal‐offspring environmental match‐mismatch experiment utilizing a 2 × 2 × 2 factorial design. Mothers were exposed to a mild heat conditioning (38°C) or control (22°C) treatment as juveniles, an acute high heat (42°C) or control (22°C) treatment as adults, then paired for breeding. The eggs produced by those females were incubated at a hyperthermic (38.5°C) or optimal temperature (37.2°C). We found that when mothers were exposed to a mild heat conditioning as juveniles, their embryos exhibited reduced water loss, longer development times, and produced hatchlings with heavier pectoralis muscles when incubated at high incubation temperatures, compared to embryos from control mothers. Mothers exposed to both the mild heat conditioning as juveniles and a high heat stressor as adults produced eggs with a higher density of shell pores and embryos with lower heart rates during development. However, there was a cost when there was a mismatch between maternal and embryo environment. Embryos from these conditioned and heat‐stressed mothers had reduced survival at control incubation temperatures, indicating the importance of offspring environment when interpreting potential adaptive effects. [ABSTRACT FROM AUTHOR]

The heterotrophic flagellates, Oxyrrhis marina were first suggested to feed Amphiascopsis cinctus, and the effects on the growth and survival rate of Amphiascopsis cinctus were studied. The results showed that the Amphiascopsis cinctus feed on Oxyrrhis marina of different concentrations finished its development and reproduction in different speed. When the Oxyrrhis marina concentrations were 200 ind·mL–1, 800 ind·mL–1, 3200 ind·mL–1 and > 10 4 ind·mL–1 respectively, the increasing concentration of Oxyrrhis marina considerably shorten the development time of Amphiascopsis cinctus between nauplii to copepodid stage from (16.30±0.82) d to (9.06±0.87) d, between copepodid stage to adult stage from (15.94±0.63) d to (10.14± 1.07) d. With the increasing concentration of flagellates, the survival rate of Amphiascopsis cinctus from nauplii to copepodid and from copepodid to adult increased from 36.72% to 70.25% and from 70.88% to 85.62% respectively, but the highest survival rate was found in the group with lower concentration (3200 ind·mL–1 ). With the increasing of food concentration, the brood amount and the hatching rate of Amphiascopsis cinctus increased from7.86 to10.67; 50.83% to 85.30% respectively, and the incubation time decreased from 8.67d to 5.12d. It can be seen that high concentration of Oxyrrhis marina can accelerate the development of Amphiascopsis cinctus and increase their reproduction efficiency. However, high concentration of flagellates reduces the survival rate of the stage from copepodid to adult, which needs further study. [ABSTRACT FROM AUTHOR]

Parental care is a critical component of many breeding systems that enhances both parent and offspring fitness. It is widely recognized that parental care varies in quality and quantity in response to variation in offspring need, parental condition, and ecological context. One context that has been underexplored, however, is the presence of extensive parental care at night, with many parental care studies focused on diurnal care. To fully understand the evolution of parental care, both diurnal and nocturnal care must be accounted for. Here, we show that nocturnal parental care exists in the clownfish Amphiprion percula, with males and females actively caring for offspring at night throughout embryo development and during hatching within a laboratory setting. At night, as during the day, males continue to be the dominant caregiver and both parents increase care as embryos mature. However, females provide substantially more care at night than during the day. We also document three new parental care behaviors at night that are not seen during the day: vigorous fanning, vigorous mouthing, and anemone biting. These behaviors are particularly frequent during hatching, and they may serve to assist the hatching process by helping embryos transition from the benthic to the pelagic environment. This study contributes to our understanding of parental care, demonstrating the importance of considering nocturnal care if we are to gain a complete understanding of the evolution of parental care. [ABSTRACT FROM AUTHOR]

Simple Summary: Chicken meat is one of the main protein sources of animal origin worldwide and its production has been increasing steadily. These chickens have huge growth potential and a short production period, so all the factors that affect the vitality of day-old birds are getting more and more important. An other important issue in animal production is the decreased use of antibiotics to stabilize the bacteriota composition of the gut. In this article, the effects of parent flocks with different ages and the hatching time of the chickens were evaluated according to the production parameters, hatchability, and gut bacteriota composition of chickens. From the results, it can be concluded that the live weight of day-old chickens is crucial because it determines the growth rate of birds for the whole fattening period. Different parent flocks had no effect, but the hatching time modified the bacterium composition of the ceca at day 11. The reason for this could be the differences in the bacteriota colonization in the hatcher and the feed and water access between the early- and late-hatched chickens. This trial was carried out to find out the effects of the parent flock and hatching time of broiler chickens on the production traits and bacteriota development of animals. Two sets of 730 hatching eggs were collected from two different parent flocks with ages of 25 and 50 weeks. In the hatchery, both groups were divided into two subgroups: those hatched during the first 10 and the subsequent 10 h of the hatching window. A feeding trial was carried out afterwards, using the four treatments in six replicate floor pens and feeding commercial starter, grower, and finisher diets that contained all the nutrients according to the breeder's recommendations. The day-old chickens of the older parent flock and those hatched later were heavier, and this advantage remained until the end of the production period. The different ages and origins of the parent flocks failed to modify the microbiological parameters of the chicken's ceca; however, the hatching time significantly influenced the different bacteriota diversity indices: the late-hatched chickens showed higher Bacteroidetes and lower Firmicutes and Actinobacteria abundances at day 11. These treatments resulted in differences in the main families, Ruminococcaceae, Lactobacillaceae, and Bacteroidaceae. These differences could not be found at day 39. [ABSTRACT FROM AUTHOR]

Caspian terns (Hydroprogne caspia Pallas, 1770) present a sub‐cosmopolitan but scattered distribution, and many of its colonies are in a vulnerable state. The species has been listed in the Red Data Book of the Russian Federation and is covered by the Agreement on the Conservation of African‐Eurasian Migratory Waterbirds. We observed the colonies of Caspian terns repeatedly in the breeding season from May to June on the islands of Lake Chany from 1985 to 2011. We recorded clutch size, eggshell coloration and measured egg length and width to the nearest 0.1 mm with a caliper. Furthermore, we recorded the fate and hatching date of individual eggs and determined the clutch initiation date. Head, bill, tarsus length, and body weight of newly hatched chicks were measured. Caspian tern colony size changed between years from 50 nests in 1985 to 513 in 1999; therefore, the sample size of measured eggs varied from 90 to 1045. A total of 4137 eggs and 570 chicks were measured. We provide new information for this species nesting in west Siberia, which is important to compare with other local results. The presented data set is a novel long‐term data set on an isolated population of this species in center of Eurasian continent. The complete data set for this abstract published in the Data Article section of the journal is available in electronic format in MetaCat in JaLTER at http://db.cger.nies.go.jp/JaLTER/metacat/metacat/ERDP-2023-02.1/jalter-en. [ABSTRACT FROM AUTHOR]

Birds face strong selective pressures to complete individual nesting attempts as quickly as possible to minimize exposure of nests to predators and weather, maximize renesting potential, and maximize hatching success. As a result, the duration of developmental periods and of overall nest periods are often relatively constant within species. However, birds may sometimes be subject to acute energetic constraints that may preclude them from initiating incubation at the optimal time. We report an extraordinary case of delayed incubation by a female Burrowing Owl (Athene cunicularia) in Oregon, USA, which contrasted sharply with a large sample of nests monitored by motion-activated video cameras in western North America from 2015 to 2018. The focal female delayed incubation by 11 d following clutch completion and subsequently experienced near total hatching failure of her clutch. This observation corroborates previous experimental studies regarding the limits to egg viability and trade-offs between the timing of incubation onset and hatching success. These findings illustrate the acute trade-offs faced by nesting birds, and the cost of delayed incubation that we observed in this owl could help explain the cause of asynchronous hatching. Las aves enfrentan fuertes presiones selectivas para completar sus intentos de anidamiento individuales tan rápido como sea posible, para minimizar la exposición del nido a depredadores y al tiempo, maximizar potencial de reanidamiento y maximizar éxito de eclosión. Como resultado, la duración de los periodos de desarrollo y los periodos de anidamiento generales son a menudo relativamente constantes dentro de las especies. Sin embargo, las aves pueden a veces estar sometidas a limitaciones energéticas agudas que pueden impedirles iniciar la incubación en un tiempo óptimo. Reportamos un caso extraordinario de retraso de incubación de una hembra de búho Athene cunicularia en Oregon, Estados Unidos, que contrastó fuertemente con una muestra grande de nidos monitoreados por video cámaras activadas por movimiento en el oeste de Norteamérica de 2015 a 2018. La hembra focal postergó la incubación 11 días después de la puesta y a continuación experimentó una pérdida casi total de la puesta. Esta observación corrobora estudios experimentales previos acerca del límite de viabilidad de los huevos y la compensación entre el tiempo de incubación y el éxito de eclosión. Estos hallazgos ilustran las fuertes compensaciones que enfrentan las aves ponedoras y el costo del retraso de la incubación que observamos en este búho podría ayudar a explicar la causa de su eclosión asincrónica. Palabras clave: asincronía de eclosión, fallo en eclosión, limitaciones energéticas, tamaño de puesta, viabilidad de huevos. [ABSTRACT FROM AUTHOR]

One of the obstacles often encountered in white shrimp farming is the presence of bacterial diseases caused by Vibrio group bacteria. One of the efforts to control Vibriosis is by using antagonistic bacteria as biocontrol agents, one of which is using Pseudomonas diminuta. In this study, P. diminuta and Vibrio harveyi were co-cultured to determine the optimal density and effective incubation time of P. diminuta which could provide the highest inhibition of V. harveyi growth. This study used a completely randomized design with six treatments P0 (P. diminuta 105 CFU/ml), P1 (V. harveyi 106 CFU/ml), P2 (P. diminuta 105 CFU/ml+V. harveyi 106 CFU/ ml), P3 (P. diminuta 106 CFU/ml+V. harveyi 106 CFU/ml), P4 (P. diminuta 107 CFU/ml+V. harveyi 106 CFU/ml), P5 (P. diminuta 108 CFU/ml+V. harveyi 106 CFU/ml). The results of this study showed that P2, P3, P4, and P5 had decreased growth of V. harveyi when compared to control P1 (V.harveyi 106 CFU/ml). The decrease in the growth of V. harveyi occurred in the 8th to 48th hour. V. harveyi in P3 (2.72 × 108 CFU/ml), P2 (2.80 × 108 CFU/ml), P4 (2.96 × 108 CFU/ml) and P5 (2.90 × 108CFU/ml) at the 48th hour of incubation was lower than P1 (3, 15×108CFU/ml). Based on the results of the Duncan test showed that P2, P3, P4, and P5 were significantly different (p <0.05) from P1. From this study, it was concluded that administration of P. diminuta at a density of 106 CFU/ml was able to reduce the growth of V. harveyi. The greatest decrease in the growth of V. harveyi occurred at the 48th hour. [ABSTRACT FROM AUTHOR]

[Objectives] To improve current rearing methods for Simulium xingyiense to enable the maintenance of two consecutive generations under laboratory conditions. [Methods] We designed and built emergence cups, mating tubes, blood-feeding apparatus and oviposition tubes, and modified a commercially available miniature aquarium for hatching eggs and rearing successive generations. The first generation was reared as follows: pupae were collected in the field and placed in emergence cups until adults emerged. Adults were then transferred to mating tubes for 30 minutes after which females were transferred to the blood-feeding apparatus for 90 minutes. Engorged females were placed in oviposition tubes until they laid eggs, which were then hatched in the modified aquarium and reared until the larvae pupated. The second generation was reared by repeating these steps with pupae from the first generation. All experiments were carried out at a temperature of 20 °C and a relative humidity of 70%. The effects of different feeding media temperatures and compositions on engorgement and oviposition rates were measured and compared. [Results] Serum medium enriched with ATP was found to be the most appealing to female flies. The highest engorgement rate was measured at a medium temperature of 34 °C. Female flies preferred bovine serum medium, and the higher its serum content, the higher their oviposition rate. Under the above optimal conditions, the female engorgement rate was 25.3%, the oviposition rate was 29.4%, each female produced an average of 163.5 eggs and the hatching rate was 85.5%. The larval stage lasted 13-15 days with a pupation rate of 10.7%. Adults emerged after 4-6 days at an emergence rate of 95.2%. [Conclusion] Two consecutive generations of S. xingyiense can be reared from pupae under laboratory conditions for subsequent molecular experiments. However, the pupation rate was low, so finding a way to increase this would further improve the captive rearing of this species. [ABSTRACT FROM AUTHOR]

Copyright of International Journal of Agriculture & Wildlife Science is the property of International Journal of Agriculture & Wildlife Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Although embryo transfer is widely applied in cattle, many of the transferred embryos do not result in pregnancy. To determine a new parameter for bovine embryo evaluation, we investigated the relationships between in vitro hatchability and embryo morphological parameters using optical coherence tomography (OCT) that we established recently. Bovine embryos were obtained from Japanese Black cattle by in vitro fertilization (IVF). The quality of the blastocysts was examined under an inverted microscope and confirmed as Codes 1-3 according to the IETS standards for embryo evaluation. The OCT images of the embryos were captured on Day 7 after IVF, and the embryos were cultured until Day 9 to determine their hatchability. During OCT, the embryos were irradiated with near-infrared light for a few minutes to obtain three-dimensional images. In total, 22 parameters were assessed for each of the 42 embryos, of which 25 hatched (H embryos) and 17 did not (NH embryos). The thickness of the trophectoderm (TE) and TE+zona pellucida (ZP) was lesser, and the volumes of the TE, ZP, blastocoel, and whole embryo and blastocoel diameter were greater in the H embryos than in the NH embryos. PCA identified that the increase in the blastocoel-related value along with the decrease in the thickness-related value of the TE and/or ZP could be indicators for evaluating the hatchability of bovine IVF embryos. These results support the idea that OCT-captured structural data of blastocyst-stage embryos can be used as a potential model to predict the quality of bovine embryos. [ABSTRACT FROM AUTHOR]

The article explores how hydrothermal springs impact the breeding habits of deep-sea octopuses. It is reported that researchers found that these springs create ideal conditions for octopus mating, nesting, and accelerated embryonic development. It further emphasizes the significance of deep-sea heat sources in influencing species behaviors and reproductive success.

Understanding the spawning and rearing habitats of fishes is critical to effective fisheries management and conservation. Longfin smelt Spirinchus thaleichthys is an imperiled migratory fish that is believed to spawn and rear in habitats of varying salinities; however, optimal conditions for each stage remain unknown. Here, we examined the effects of variation in salinity on egg fertilization, hatch success, and larval growth and survival. Eggs that were fertilized in freshwater (0.4 ppt) exhibited a significantly higher fertilization rate (81%) than those fertilized in brackish water (62% at 5 ppt), with no detectible effects of fish origin or female size. In contrast to fertilization rates, once the eggs were fertilized, their hatching rates were not affected by the fertilization salinity, incubation salinity, nor their interaction; however, hatching success and larval survival both increased with increasing maternal body mass. Larval growth rate appeared to be independent of salinity and maternal size. Taken together, the results indicate that fertilization is possible at a range of salinities, but optimal at lower salinities for longfin smelt; however, embryos and larvae can perform well across a range of salinities. Furthermore, results indicated that larger mothers produced high-quality offspring, a finding that supports the "bigger is better" paradigm in fisheries science and management. These results likely explain, in part, the spawning and rearing behaviors of wild longfin smelt and suggest that the conservation culture program would likely be optimized by utilizing freshwater fertilization and larger females as broodstock. [ABSTRACT FROM AUTHOR]

Introduction: Cultured fish species are increasingly exposed to fungi and bacteria in the rearing environment, often causing disease and mortality causing aquaculture producers to rely on the use of chemical therapeutants which may have negative consequences for both human and environmental health. This study investigated the effect of humic acid as a treatment to reduce fungal and bacterial infections to increase survival during the incubation of rainbow trout (Oncorhynchus mykiss) eggs. Methods: Humic acid, an aqueous extract of oxidized lignite was added to water entering both stacked tray and jar type incubators at a dosage rate of 5 mg/L from fertilization until hatching. Results: The water treatment eliminated observable fungus and significantly improved survival until hatching in the treated incubator trays (77.2%) compared to the untreated controls (55.5%) (p = 0.001). Egg survival was not improved in the incubator jars. The humic acid reduced bacterial diversity, but only in the stacked tray incubators and altered bacterial composition of the water after 20 days of treatment. Discussion: The treatment increased the bacterial abundance of Burkholderiales, positively associated with healthy fish eggs and decreased the abundance of Flavobacterium and Aeromonas, known fish pathogens. These findings support the topical treatment of humic acid as a potential alternative treatment to prevent fungal infections and reduce mortality during incubation of rainbow trout eggs. [ABSTRACT FROM AUTHOR]

Mediterranean endorheic wetlands are strongly affected by local meteorological events, so they undergo frequent unpredictable disturbances, such as episodes of high salinity or desiccation. In this context, salinity and temperature may be crucial for determining the structure of zooplankton communities and regional biodiversity, since they may trigger the hatching of egg bank in different ways. The goal of this study is to assess the combined role of these two variables on the zooplankton assemblage emerging from the egg bank. We hypothesize that temperature and salinity affect the community structure in a non-linear way, that is, both factors interact and modify the magnitude of their effects. We performed a laboratory factorial design where the same sediment was incubated under different thermal and salinity conditions, reducing the potential effects of other possible confusion factors. Community structure was described by measuring cumulative abundances, species composition, richness, and diversity. Our results showed that the community structure was strongly determined by salinity at all experimental temperatures. In contrast, the magnitude of the temperature effect depended on salinity. The high variability among replicates when salinity and temperature increased suggests that climate change might lead to unpredictable patterns of the community emerging from the egg bank. [ABSTRACT FROM AUTHOR]