Spring resting egg production of the calanoid copepod, Eurytemora affinis, in a freshet-dominated estuary.

Seasonal peaks in river discharge, such as snowmelt-dominated freshets, are predictable events that can have a large effect on flushing rates and salinity in estuaries. Resting eggs, which many coastal and estuarine copepods produce for overwintering or aestivation, could also serve to bridge predictable peaks in river discharge. We assessed the timing of resting egg production of the egg-carrying estuarine copepod, Eurytemora affinis (Poppe), in relation to river discharge in the Fraser River Estuary, Canada. Approximately 30 field-collected females were individually incubated on 12 occasions over the period February 2015-May 2016. Eurytemora affinis abundance and population structure were investigated from vertical net tow samples collected twice monthly to monthly. Resting eggs occurred primarily in May 2015 and May 2016 (6.5 and 9.2 eggs day-1, respectively), a month prior to peak flows, and the proportion of offspring that were resting eggs increased with river discharge. Eurytemora affinis reached a minimum abundance in July 2015, when the population was dominated by adults (86%). Resting egg production in E. affinis is typically considered an overwintering mechanism but we suggest that the ultimate driver of resting egg production in this population is avoidance of flushing and/or low salinities.

Legacy and Emergent Contaminants in Glaucous-winged Gull Eggs from Canada's Pacific Coast: Spatial Distribution, Temporal Trends, and Risks for Human Consumers.

Using glaucous-winged gull (Larus glaucescens) eggs from Canada's Pacific coast, we investigated spatial and temporal trends (2008-2022) of a suite of legacy and emergent contaminants, including 16 perfluoroalkyl substances (PFASs), 15 polybrominated diphenyl ethers (PBDEs), 7 alternative halogenated flame retardants (AHFRs), total mercury (THg), as well as stable isotopes of carbon (δ13C) and nitrogen (δ15N). Legacy organochlorines (OCs) were also measured in eggs in 2020 for a human health risk assessment (HHRA). Between 2008-2022, glaucous-winged gull eggs from more urban-influenced colonies (Mandarte Island) were ∼2x more contaminated with PFASs, PBDEs, AHFRs, and THg than eggs from the offshore/marine colony (Cleland Island), suggesting different source regions and dietary exposures. Concentrations of Σ15PBDEs declined linearly among colonies (p < 0.001), consistent with several North American phase-outs and regulatory restrictions dating back to the early/mid 2000s. Conversely, temporal trends for PFOS, Σ12PFCAs, Σ7AHFRs, and THg were characterized by a combination of second-order declines and non-linear increases in recent years. After correcting THg for dietary shifts using δ15N, THg concentrations followed a U-shaped trend at Mandarte and Cleland Islands, while those at Mitlenatch Island remained relatively constant over time. Increasing trends for some contaminants coincided with both an increase in δ13C and δ15N. For the HHRA, all gull eggs in 2020 had hazard quotients (HQs) < 0.2, indicating no foreseeable risk or harm for First Nations consumers for certain contaminants. Our findings indicate that spatio-temporal trends of persistent organic contaminants and THg in Pacific glaucous-winged gull eggs are influenced by a combination of factors, including the impact of regulations on anthropogenic emissions, as well as changes in foraging behaviour and food-web structure.

Metals in honey, cow's milk and eggs in North-East Algeria and health risk.

Metal contamination of foodstuffs is a major public health challenge of increasing concern. The present study aimed to determine lead, cadmium and mercury in honey, cow's milk and poultry eggs collected from the North-Eastern region of Algeria and to evaluate the health risks associated with their regular consumption. To this aim 30 samples of each foodstuff were analysed using ICP-MS. Among the quantified heavy metals, Pb was found at the highest level in both honey (0.752 ± 0.16 µg g-1) and poultry egg (0.988 ± 0.19 µg g-1) in the region of Skikda. The highest values of Cd (0.798 ± 0.12 µg g-1) and Hg (0.097 ± 0.02 µg g-1) were found in poultry eggs collected from the same region. For infants the Hazard Index was well above 1 in honey samples from all three locations, in cow's milk collected from Mila and Skikda and in poultry eggs collected from Skikda.

Per- and Polyfluoroalkyl Substances (PFAS) Accumulation, Reproductive Impairment, and Associations with Nestling Body Condition in Great (Parus major)- and Blue Tits (Cyanistes caeruleus) Living near a Hotspot in Belgium.

Due to the limited number of field studies investigating associations between environmentally relevant per- and polyfluoroalkyl substances (PFAS) mixtures and reproductive impairment, there is uncertainty as to whether birds are affected by PFAS pollution, whether species differ in sensitivity to PFAS, and whether the observed reproductive impairment is caused by PFAS or rather due to other potential confounding variables. Therefore, we investigated PFAS concentrations in eggs and blood plasma of great tit (Parus major) and blue tit (Cyanistes caeruleus) nestlings near a PFAS hotspot in Belgium, reproductive impairment, and associations between the accumulated levels and nestling body condition. In total, 29 eggs and 22 blood plasma samples of great tit clutches, and 10 egg and 10 blood plasma samples of blue tit clutches, were collected. Despite more types of PFAS being detected in eggs compared to plasma, only minor differences in profiles were observed between species. On the other hand, tissue-specific differences were more pronounced and likely reflect a combination of maternal transfer and dietary exposure post-hatching. Despite the high concentrations detected in both species, limited reproductive impairment was observed. Our results support previous findings that great tits and blue tits may not be very susceptible to PFAS pollution and provide evidence that other factors, including ecological stoichiometry, may be more important in explaining inter-species variation in PFAS accumulation and reproductive impairment.

Biological Properties of the Mucus and Eggs of Helix aspersa Müller as a Potential Cosmetic and Pharmaceutical Raw Material: A Preliminary Study.

In recent years, snail mucus (SM) has become popular as an active ingredient in cosmetic and pharmaceutical products. In turn, snail eggs (SEs) also seem to be a promising active compound, but the biological activities of SEs are significantly less known. Therefore, our preliminary study aimed to compare the biological activities of the SEs and SM of Helix aspersa Müller. The metabolomic analysis (LC-MS technique), determination of the antimicrobial activity (agar diffusion test, broth microdilution methods), antioxidant activity (ABTS assay), cytotoxicity assay (MTT), and proapoptotic properties (flow cytometry) of the SEs and SM were evaluated. It was found that the SEs and SM contain 8005 and 7837 compounds, respectively. The SEs showed antibacterial activity against S. aureus (MIC 12.5 mg/mL) and P. aeruginosa (MIC 3.12 mg/mL). The EC50 estimation of the antioxidant activity is 89.64 mg/mL and above 100 mg/mL for the SEs and SM, respectively. The SEs also inhibited the cell proliferation of cancer cell lines (HCT-116, MCF-7, HT-29) more strongly compared to the SM. The highest proportion of apoptotic cells in HCT-116 was observed. The reach composition of the compounds in the SEs and SM may be crucial for the creation of new cosmetic and pharmaceutical raw materials with different biological activities. However, further extended studies on the biological activities of H. aspersa-delivered materials are still necessary.

Determination and evaluation of canthaxanthin and ß-apo-8'-carotenoid ethyl ester in chicken eggs and meat in Tianjin.

Canthaxanthin and ß-apo-8'-carotenoid ethyl ester are widely used as feed additives in poultry feed for enhancing the color of poultry products. The excessive intake of the two colorants can cause health damage. According to the European Food Safety Authority (EFSA), the acceptable daily intake (ADI) of canthaxanthin and ß-apo-8'-carotenoid ethyl ester are 0.03 mg/kg·bw and 0.015 mg/kg·bw, respectively. Ultra-high-performance liquid chromatography-diode array detector (UPLC-DAD) was used to determine two colorants in chicken eggs and meat. A PRiME HLB solid-phase extraction cartridge was used to extract and clean-up the sample. BEH C18 column was used as the separation column, with water containing 0.1% formic acid and acetonitrile as the mobile phase. The limit of detection (LOD) was 0.05 mg/kg, and the limit of quantification (LOQ) was 0.1 mg/kg. The recoveries were between 90% and 104%. The daily intake of two colorants in chicken eggs and meat was evaluated based on the detection data, food consumption data and weight data of the population. The mean estimated daily intake (EDI) values of canthaxanthin through chicken eggs and meat were 1.09 µg/(kg·bw·d) and 0.013 µg/(kg·bw·d), respectively. The mean EDI value of ß-apo-8'-carotenoid ethyl ester through eggs was 0.44 µg/(kg·bw·d). The results showed that eggs were the main contributor to the daily intake of two colorants. The mean hazard quotients (HQ) values of two colorants through chicken eggs and meat was within a safe range.

Eating Egg-Rich Diets and Modeling the Addition of One Daily Egg Reduced Risk of Nutrient Inadequacy among United States Adolescents with and without Food Insecurity.

BACKGROUND: Adolescents have the poorest dietary intake throughout their lifespan. Food insecurity worsens these nutritional risks. Eggs are 1 nutrient-dense strategy to increase nutrient quality. OBJECTIVES: 1) compare usual nutrient intakes, dietary reference intakes, and protein compliance with recommendations and scores of micronutrient quality; and 2) analyze how adding 1 egg affects adolescents' nutrient profiles by food security status and egg-rich diets. METHODS: Dietary data of United States adolescents in the 2007-2018 NHANES were analyzed (14-17 y; n = 3633). Egg-rich diet levels were categorized as 1) noneggs, 2) eggs as ingredients in dishes, or 3) primarily egg dishes. Food security status was classified using the United States household food security survey module. The National Cancer Institute method was used to estimate usual nutrient intake and nutrient exposure scores [i.e., food nutrient index and total nutrient index(TNI)]. Nutrient amounts from 1 medium egg were modeled on existing intakes. Pairwise t-tests determined significant differences. RESULTS: Over 60% of adolescents risked inadequate intake of calcium, choline, magnesium, vitamin D, and vitamin E regardless of food security status. Food-secure adolescents consuming primarily egg dishes had higher mean usual intakes of lutein + zeaxanthin (1544.1 µg), choline (408.4 mg), vitamin B2 (2.3 mg), selenium (128.6 µg), vitamin D (6 µg), docosahexaenoic acid (70 mg), and protein (89.1 g) than other groups (P < 0.0002). Those consuming eggs as ingredients in dishes demonstrated higher nutrient adequacy for magnesium (scored ∼66 out of 100), potassium (scored 81), and total scores (scored 72 and 69, respectively) for the TNI and food nutrient index; and folate only (scored 92) for the TNI, than those not consuming eggs (P < 0.0002). Adding 1 egg increased choline and vitamin D usual intakes for some groups and nutrient index scores for all groups (P < 0.0005). CONCLUSIONS: Adolescents are at substantial nutritional risk that was exacerbated by food insecurity and less egg consumption.

A novel kit for enrichment of fecal helminth eggs.

We developed a new concentration kit, called the ParaEgg (PE), for easy detection trematode eggs from fecal samples in endemic areas of clonorchiasis and metagonimiasis in Korea. To create a standard of detection efficiency, 120 fecal samples were examined using the water-ether concentration method (WECM). The PE kit and Mini ParaSep (PS) kit were used to compare the detection sensitivity of 100 egg-positive and 20 egg-negative samples in WECM. Additionally, stool samples, which were intentionally spiked with 10, 20, and 30 Clonorchis sinensis eggs, were evaluated to assess the sensitivity in lowinfection cases. The PE and PS kits showed detection rates of 100% and 92%, respectively, from 100 egg-positive samples in WECM. Meanwhile, eggs were detected in 3 (PE) and 2 (PS) out of 20 egg-negative samples in WECM. The PE kit detected the highest number of eggs per gram of feces (727 on average), followed by the WECM (524) and PS kit (432). In fecal samples that were intentionally spiked with 10, 20, and 30 C. sinensis eggs, PE only detected eggs 2 out of 5 samples in 10 eggs spiked (40%), and the detection rates were 80% and 100%, respectively. The PE kit enabled a more accurate identification of trematode eggs because of the clearance of small fecal debris in the microscopic field. In conclusion, the PE kit is obviously helpful to detect and identify trematode eggs in stool examinations especially in endemic areas of clonorchiasis and metagonimiasis.

In vitro production of viable eggs from undeveloped oocytes in mouse preantral follicles by reconstructing granulosa cell-oocyte complexes†.

In vitro culture of ungrown oocytes in preantral follicles is one of the intriguing subjects being pursued to produce viable eggs in assisted reproductive technology. Previous studies have succeeded in obtaining mature eggs after in vitro culture of preantral follicles, while denuded undeveloped oocytes, which are obtained occasionally when collecting preantral follicles, seem to be almost useless. Moreover, methods to culture them efficiently to produce viable eggs have not been established yet. The present study was conducted to demonstrate in vitro culture of mouse denuded undeveloped oocytes by reconstructing granulosa cell-oocyte complexes, and to analyze cellular communication in reconstructed granulosa cell-oocyte complexes. Single denuded undeveloped oocytes were aggregated with 1 × 104 granulosa cells in wells with U-shaped bottoms in a low-binding cell culture plate for 8 days under either 20% or 5% O2, and then the reconstructed granulosa cell-oocyte complexes formed were cultured on a collagen-coated culture membrane insert for 4 days under 5% O2. At day 8 of culture, the rates of reconstructed granulosa cell-oocyte complexes formation were significantly higher in the culture group under 5% O2 (64.9%) than that under 20% O2 (42.3%; P < 0.001); furthermore, the formation of transzonal projections was observed. After maturation and fertilization, we produced matured eggs and blastocysts at higher rates (>90% and 61.9%, respectively) in the group cultured under 5% O2. After transferring 126 two- to four-cell stage embryos, six live pups were obtained. This is the first report that demonstrates production of viable eggs after in vitro culture of denuded undeveloped oocytes from preantral follicles by reconstruction of granulosa cell-oocyte complexes.

Evaluating the Economic Impacts of a Cage-Free Animal Welfare Policy in Southeast Asian and Indian Egg Production: A Systematic Review.

Animal welfare is increasingly understood to be a key component of sustainable agricultural production. Southeast Asia and India are witnessing an emerging market for cage-free egg production. To evaluate the economic sustainability of cage-free policies in the region, it is critical to understand how this transition will affect farmers' costs and revenues. In this article, we provide an overview of the available information that can inform evaluations of cage-free egg production in Southeast Asia and India. Cage-free egg producers around the world tend to experience higher costs, but these costs are offset by higher revenues. As demand for cage-free eggs is stimulated in Southeast Asia and India by retailer or government policies, we expect that producers will be capable of meeting this demand. In Asia specifically, the dominant cost component is poultry feed. We conclude that the economic viability of egg production in the region is likely to be driven by feed prices and associated government policies, rather than production system per se.

The Egg Hub Model: A Sustainable and Replicable Approach to Address Food Security and Improve Livelihoods.

Background: Despite progress in improving living standards and reduced poverty, food insecurity and malnutrition remain a significant issue worldwide. Childhood is a critical time for the intake of protein to support physical and cognitive growth, including animal-source foods like eggs which can effectively mitigate stunting in low- and middle-income countries. In Malawi, high malnutrition rates among women and children represent a significant public health challenge, but high-quality sources such as eggs remain costly, scarce, and rarely consumed by children in Malawi. The Egg Hub model, identified and piloted by local agri-food entrepreneurs and the Sight and Life Foundation in Malawi, tackles the obstacles faced by smallholder farmers, working to increase egg production, enhance availability, and improve consumption within rural communities by supporting small-scale farmers transition from unsustainable and unproductive backyard rearing to small-scale farm through access to high-quality inputs, training, loans, and a guaranteed market for their eggs. Objectives: This paper provides a detailed account of the implementation of the pilot of the Egg Hub Model in Malawi including the demand creation process, the impact of the model on producers, consumers, and operators, and the social, economic, and environmental sustainability aspects of the model. Methods: Qualitative and quantitative surveys (n = 217 consumers) were used for demand creation and qualitative surveys were used with 15 retailers to determine egg sales. With 16 farmers and the egg hub operator, business metrics, including profits and loss records, were analyzed. Results: The pilot of the Egg Hub model in Malawi supported 85 farmers to triple their egg production, allowing their communities to purchase eggs at prices reduced by 40%, benefiting an estimated number of 180,000 rural poor. Egg consumption among the target population increased from an average of 2 to 9 eggs/month and led to reduced egg wastage and better biosecurity, reducing the risk of children's exposure to chicken feces and infections. The achievements of this Egg Hub in Malawi allowed the model to be replicated in Ethiopia, Peru, and Brazil, producing 40 million eggs annually and benefiting more than half a million consumers. Conclusion: The Egg Hub model is a comprehensive and scalable solution to increase egg supply, address malnutrition and food insecurity, and improve livelihoods. The advantages include centralizing key activities through a community-centered approach, empowering female farmers, increasing access to a highly nutritious food, and economic benefits for farmers and their communities.

Brood parasitism and host-parasite relationships: Cuckoos adapt to reduce the time of hatching ahead of host nestlings by increasing egg thickness.

The phenomenon of cuckoos' brood parasitism is well known and can be investigated using applied mathematical techniques. Among adaptive features of this phenomenon are certain egg parameters that ensure their shortened incubation period (I) and thus the successful survival of their offspring. In particular, the volume of a cuckoo egg is not less than, or exceeds, that of the host species, which should, in theory, increase I. Also, cuckoo eggs have thicker shell than that of nest hosts. Here, we analyzed the available geometric dimensions of eggs in 447 species and found an inverse correlation (-0.585, p < 0.05) between I and the shell thickness-to-egg surface area ratio (T/S). A mathematical relationship was derived to calculate I depending on T/S. This premise was confirmed by comparative calculations using egg images of two parasitic species, common (Cuculus canorus) and plaintive cuckoo (Cacomantis merulinus) and their hosts: great reed warbler (Acrocephalus arundinaceus), European robin (Erithacus rubecula), rufescent prinia (Prinia rufescens), and common tailorbird (Orthotomus sutorius). An average calculated I value for cuckoo eggs was one day less than that for host eggs. Our findings unravel additional details of how cuckoos adapt to brood parasitism and specific host-parasite relationships.

Levels of PCDD/Fs, PCBs, metals and rare earth elements in eggs and vegetables from areas with different environmental contamination impacts in the Campania region (Southern Italy).

Studying the links between environmental pollution and the levels of contamination in food is an important challenge to ensure human health. Matched samples of eggs from free-range hens and vegetables were analysed to investigate the bioaccumulation of PCDD/Fs, PCBs, metals and rare earth elements. Only two egg samples resulted above the limit fixed for PCDD/Fs and the action level set for DL-PCBs. The highest concentrations were found in the eggs from an area situated in a big city affected by strong urbanisation. Although eggs and vegetables were subjected to the same environmental pollution, the PCDD/F and PCB bioaccumulation that occurred in the eggs was much higher than those in vegetables (p < 0.01). In vegetables, the highest PCDD/F and PCB concentrations were found in lettuce and potatoes grown on contaminated soil. Higher bioaccumulation of Fe and Zn occurred in eggs compared to vegetables; La, Pr, Nd, Sm and Eu were found only in lettuce samples. The results of this study may provide important data useful in the risk assessment of human exposure through diet in accidents involving dangerous chemicals. Furthermore, the estimated weekly intakes calculated for PCDD/Fs and PCBs highlighted that, although vegetables accumulate very low concentrations of these contaminants, they contribute more than eggs to human exposure.

Methicillin-Resistant Staphylococcus aureus (MRSA) in Different Food Groups and Drinking Water.

Methicillin-resistant Staphylococcus aureus (MRSA) has been included by the World Health Organization in its list of "priority pathogens" because of its widespread prevalence and the severity of the infections it causes. The role of food in infections caused by MRSA is unknown, although strains of this microorganism have been detected in various items for human consumption. In order to gain an overview of any possible role of food in MRSA infections, a review was undertaken of studies published between January 2001 and February 2024 relating to MRSA. These comprised research that focused on fish and shellfish, eggs and egg products, foods of vegetable origin, other foodstuffs (e.g., honey or edible insects), and drinking water. In most of these investigations, no prior enrichment was carried out when isolating strains. Three principal methods were used to confirm the presence of MRSA, namely amplification of the mecA gene by PCR, amplification of the mecA and the mecC genes by PCR, and disc diffusion techniques testing susceptibility to cefoxitin (30 µg) and oxacillin (1 µg). The great diversity of methods used for the determination of MRSA in foods and water makes comparison between these research works difficult. The prevalence of MRSA varied according to the food type considered, ranging between 0.0% and 100% (average 11.7 ± 20.3%) for fish and shellfish samples, between 0.0% and 11.0% (average 1.2 ± 3.5%) for egg and egg products, between 0.0% and 20.8% (average 2.5 ± 6.8%) for foods of vegetable origin, between 0.6% and 29.5% (average 28.2 ± 30.3%) for other foodstuffs, and between 0.0% and 36.7% (average 17.0 ± 14.0%) for drinking water.

The Effect of Synthetic Polyamine BPA-C8 on the Fertilization Process of Intact and Denuded Sea Urchin Eggs.

Sea urchin eggs are covered with layers of extracellular matrix, namely, the vitelline layer (VL) and jelly coat (JC). It has been shown that sea urchin eggs' JC components serve as chemoattractants or ligands for the receptor on the fertilizing sperm to promote the acrosome reaction. Moreover, the egg's VL provides receptors for conspecific sperm to bind, and, to date, at least two sperm receptors have been identified on the surface of sea urchin eggs. Interestingly, however, according to our previous work, denuded sea urchin eggs devoid of the JC and VL do not fail to become fertilized by sperm. Instead, they are bound and penetratedby multiple sperm, raising the possibility that an alternative pathway independent of the VL-residing sperm receptor may be at work. In this research, we studied the roles of the JC and VL using intact and denuded eggs and the synthetic polyamine BPA-C8. BPA-C8 is known to bind to the negatively charged macromolecular complexes in the cells, such as the JC, VL, and the plasma membrane of echinoderm eggs, as well as to the actin filaments in fibroblasts. Our results showed that, when added to seawater, BPA-C8 significantly repressed the Ca2+ wave in the intact P. lividus eggs at fertilization. In eggs deprived of the VL and JC, BPA-C8 binds to the plasma membrane and increases fibrous structures connecting microvilli, thereby allowing the denuded eggs to revert towards monospermy at fertilization. However, the reduced Ca2+ signal in denuded eggs was nullified compared to the intact eggs because removing the JC and VL already decreased the Ca2+ wave. BPA-C8 does not cross the VL and the cell membrane of unfertilized sea urchin eggs to diffuse into the cytoplasm at variance with the fibroblasts. Indeed, the jasplakinolide-induced polymerization of subplasmalemmal actin filaments was inhibited in the eggs microinjected with BPA-C8, but not in the ones bath-incubated with the same dose of BPA-C8.

Transparent mechanism of salted egg (white) hierarchically and synergistically driven by NaCl, NaOH and thermal treatment: Based on empirical data and molecular simulation.

Currently, it is a challenge that the yolk in salted preserved egg tends to preserved egg yolk due to extreme NaOH treatment. Therefore, NaCl, NaOH and thermal were successfully used to prepare a new translucent salted quail egg (T-SQE), which combined advantages of preserved egg white with transparent appearance and salted egg yolk with unique texture and odour. Moreover, transparency of opaque gel (Transmittance: 0.09 %) subjected to NaCl and thermal was demonstrated to be improved under the synergistic effect of NaOH (8.55 %) via empirical data and molecular simulation. The disordered and dense network in opaque T-SQE induced by NaCl and thermal tended to form an ordered, porous and transparent structure in presence of NaOH, with more immobilized water that was poorly bonded to protein, larger radius of gyration and lower hydrophobic interaction. This research provides new insight into understanding the influence of hierarchy and synergism on transparency of egg products.

Automating parasite egg detection: insights from the first AI-KFM challenge.

In the field of veterinary medicine, the detection of parasite eggs in the fecal samples of livestock animals represents one of the most challenging tasks, since their spread and diffusion may lead to severe clinical disease. Nowadays, the scanning procedure is typically performed by physicians with professional microscopes and requires a significant amount of time, domain knowledge, and resources. The Kubic FLOTAC Microscope (KFM) is a compact, low-cost, portable digital microscope that can autonomously analyze fecal specimens for parasites and hosts in both field and laboratory settings. It has been shown to acquire images that are comparable to those obtained with traditional optical microscopes, and it can complete the scanning and imaging process in just a few minutes, freeing up the operator's time for other tasks. To promote research in this area, the first AI-KFM challenge was organized, which focused on the detection of gastrointestinal nematodes (GINs) in cattle using RGB images. The challenge aimed to provide a standardized experimental protocol with a large number of samples collected in a well-known environment and a set of scores for the approaches submitted by the competitors. This paper describes the process of generating and structuring the challenge dataset and the approaches submitted by the competitors, as well as the lessons learned throughout this journey.

Mating of unfed, engorged, and partially to fully gravid Aedes aegypti (Diptera: Culicidae) female mosquitoes in producing viable eggs.

BACKGROUND: Understanding the relationship between blood-feeding and mating is important in effectively managing the most well-adapted vector insect, Aedes aegypti (Linnaeus). Although extensive studies have investigated the behavioural aspects of Aedes such as blood-feeding, mating, and their relationship, several knowledge gaps still exist. Therefore, the present study was undertaken to determine the possibility of successful mating by unfed, engorged, and partially to fully gravid (up to 5 days after blood-feeding with fully developed eggs) female Ae. aegypti mosquitoes and production of viable eggs. METHODS: Mating of sexually mature adult Aedes aegypti was allowed in three different ways. In control 1, the females were allowed to mate before taking blood meal, and in control 2, the females were not at all allowed to mate. In the experiment, the females were separated into six categories, viz. D-0 to D-5. In D-0, the females were allowed to mate immediately after the bloodmeal and, in D-1, the females were allowed to mate on the first day of blood feeding, likewise, the females of D-2, D-3, D-4 and D-5 were allowed to mate on 2nd, 3rd, 4th and 5th day of blood feeding. Ovitrap was uniformly kept on the 4th day of blood feeding for the cages D-0 to D-3 for 1 h and then removed and for the cages D-4, and D-5, the ovitrap was kept on 4th and 5th day of blood feeding for 1h immediately after mating. The total number of eggs and the total number of hatching were counted. In the subsequent days, the entire experiment was replicated two times with different cohorts of mosquitoes, and the mean value of three experiments was used to draw Excel bars with 5% error bars and also for the statistical analysis. RESULTS: It was found that mating just before oviposition was sufficient to produce 1581 eggs (70% compared with control) and fertilize 1369 eggs (85% compared with total eggs laid), which is far higher than the 676 non-hatching (unfertilized) eggs (30%) laid by unmated females. Although mating is not essential for producing eggs, our study shows that even brief exposure to the semen and seminal fluids greatly enhances the oviposition and hatching efficiency, even if the mating occurs just before oviposition. However, those females mating before blood-feeding and those mating after blood-feeding produced 2266 and 2128 eggs, with hatching rates of 96.78% and 95.54%, respectively. Hence, the retention time of seminal fluid in the female seems to influence the number of eggs laid and the number of eggs hatched. CONCLUSIONS: In general, mating is possible in Ae. aegypti even minutes before oviposition and is sufficient to produce a greater number of viable eggs.

The impact of electromagnetic fields generated by high-voltage power lines on the spatial arrangement of pike (Esox Lucius Linnaeus 1758) embryos.

Urbanization and technological advancements result in the dispersion of antropogenic electromagnetic fields (EMF) that can affect on ecosystems. Therefore, it is important to understand their impact on the environment. Aquatic ecosystems are subject to EMF as part of various electricity sources, e.g., high-voltage transmission lines (HVTL). We examined the impact of EMF generated by HVTL on the spatial arrangement and survival of pike (Esox lucius) embryos. Fertilized eggs were incubated under two HVTL configurations 110 kV and 220 kV compared with a control group devoid of anthropogenic EMF. Embryo orientation and survival were monitored until blastopore closure. The control group showed dominance in the arrangement of embryos along the N-S, NNW-SSE, and NNE-SSW axes, with a slight prevalence of northern directions. EMF originating from HVTL did not exert a significant influence on the spatial arrangement of pike embryos, although some deviations from the arrangement noticed in the control group were observed. Increased embryo mortality was observed only at 110 kV site, but probably due to factors unrelated to EMF. In conclusion, EMF generated by HVTL did not significantly change pike embryo orientation or chances of survival. However, longer exposure or higher EMF levels could provoke notable reactions, requiring ongoing evaluation as power networks continue to spread more widely.

Non-destructive prediction of fertility and sex in chicken eggs using the short wave near-infrared region.

The objective of this study was to evaluate the ability of a handheld near-infrared device (900-1600 nm) to predict fertility and sex (male and female) traits in-ovo. The NIR reflectance spectra of the egg samples were collected on days 0, 7, 14 and 18 of incubation and the data was analysed using principal component analysis (PCA), linear discriminant analysis (LDA) and support vector machines classification (SVM). The overall classification rates for the prediction of fertile and infertile egg samples ranged from 73 % to 84 % and between 93 % to 95 % using LDA and SVM classification, respectively. The highest classification rate was obtained on day 7 of incubation. The classification between male and female embryos achieved lower classification rates, between 62 % and 68 % using LDA and SVM classification, respectively. Although the classification rates for in-ovo sexing obtained in this study are higher than those obtained by chance (50 %), the classification results are currently not sufficient for industrial in-ovo sexing of chicken eggs. These results demonstrated that short wavelengths in the NIR range may be useful to distinguish between fertile and infertile egg samples at days 7 and 14 during incubation.