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The cattle production system focuses on maintaining an animal-based food supply with a lower number of cattle. However, the fecundity of dairy cows has declined worldwide. The reproductive tract microbiome is one of the important factors which can influence bovine fecundity. Therefore, reproductive tract microbiomes have been explored during the estrus cycle, artificial insemination, gestation, and postpartum to establish a link between the micro-communities and reproductive performance. These investigations suggested that microbial dysbiosis in the reproductive tract may be associated with declined fertility. However, there is a scarcity of comprehensive investigations to understand microbial diversity, abundance, shift, and host-microbiome interplay for bovine infertility cases such as repeat breeding syndrome (RBS). This review summarizes the occurrence and persistence of microbial taxa to gain a better understanding of reproductive performance and its implications. Further, we also discuss the possibilities of microbiome manipulation strategies to enhance bovine fecundity. [ABSTRACT FROM AUTHOR]

The role of epigenetics in regulating caste polyphenism in social insects has been debated. Here, we tested the importance of histone de/acetylation processes for the maintenance of queen hallmarks like a high fecundity and a long lifespan. To this end, we performed RNA interference experiments against histone deacetylase 3 (HDAC3) in the termite Cryptotermes secundus. Fat body transcriptomes and chemical communication profiles revealed that silencing of HDAC3 leads to signals indicative of queen hallmarks. This includes fostering of queen signalling, defence against ageing and a reduction of life‐shortening IIS (insulin/insulin‐like growth factor signalling) and endocrine JH (juvenile hormone) signalling via Kr‐h1 (Krüppel‐homologue 1). These observed patterns were similar to those of a protein‐enriched diet, which might imply that histone acetylation conveys nutritional effects. Strikingly, in contrast to solitary insects, reduced endocrine JH signalling had no negative effect on fecundity‐related vitellogenesis in the fat bodies. This suggests an uncoupling of longevity pathways from fecundity in fat bodies, which can help explain queens' extraordinary lifespans combined with high fecundity. [ABSTRACT FROM AUTHOR]

STUDY QUESTION Is there an association between male creatinine levels and time to pregnancy (TTP) in couples planning pregnancy? SUMMARY ANSWER Low and high male creatinine concentrations were associated with reduced couple fecundity. WHAT IS KNOWN ALREADY Abundant evidence suggests male creatinine dysfunction is associated with infertility in males with kidney diseases. However, the association of preconception creatinine levels with reduced fecundity among general reproductive-aged couples lacks evidence from an in-depth population study. STUDY DESIGN, SIZE, DURATION Based on the population-based cohort study from the National Free Preconception Check-up Projects, 4 023 204 couples were recruited and met the inclusion criteria from 1 January 2015 to 31 December 2017. They were planning pregnancy and were followed up every 3 months until achieving pregnancy as detected by gynaecological ultrasonography or were followed up for 1 year for the analysis of TTP. PARTICIPANTS/MATERIALS, SETTING, METHODS Cox regression models were used to estimate hazard ratios (HRs) and 95% CI for creatinine deciles. Restricted cubic spline regression was adopted for the dose–response relationship of creatinine with HRs. R statistical software was used for data analysis. MAIN RESULTS AND THE ROLE OF CHANCE Of the included participants, 2 756 538 (68.52%) couples successfully conceived. The median male serum creatinine was 81.50 μmol/l. Compared with the reference group (78.00–81.49 μmol/l) including the median creatinine, fecundity in the first (≤64.89 μmol/l), second (64.90–69.99 μmol/l), third (70.00–73.99 μmol/l), and tenth (≥101.00 μmol/l) deciles decreased by 8%, 5%, 2%, and 1%, respectively (Decile 1 Adjusted HR 0.92, 95% CI 0.91–0.92; Decile 2 Adjusted HR 0.95, 95% CI 0.95–0.96; Decile 3 Adjusted HR 0.98, 95% CI 0.97–0.99; Decile 10 Adjusted HR 0.99, 95% CI 0.98–0.99). An inverse-U-shaped association was consistently presented among males such that non-inferiority for fecundity was shown when creatinine was in the 81.66–104.90 μmol/l range (P for non-linearity < 0.001). For males over 40 years old, the risk of fecundity impairment was more obvious and the recommended range of creatinine levels for TTP was reduced and more narrow, compared with that for younger males. LIMITATIONS, REASONS FOR CAUTION Not including the time couples spend preparing for pregnancy before enrolment would lead to an overestimation of fecundity; additionally some couples place pregnancy plans on hold due to special emergencies, which would not have been recognized. Due to the lack of information regarding semen quality, psychological factors, sexual intercourse frequencies, and hazardous environmental factors, we could not adjust for these factors. Some variates were self-reported and dichotomized, which were prone to bias. Direct variables reflecting muscle mass and impaired kidney function were lacking. Thus, extrapolation should be done with caution. WIDER IMPLICATIONS OF THE FINDINGS Male creatinine is associated with couples' fecundity and the relationship varied by age. This study provides a better understanding of the potential implications and significance of different creatinine levels and their association with the clinical significance regarding couples' fecundity. STUDY FUNDING/COMPETING INTEREST(S) This research has received funding from the National Natural Science Foundation of China (Grant No. 81872634), the Basic Research Funds of Central Public Welfare Research Institutes of China (Grant No. 2023GJZ03), the National Key Research and Development Program of China (Grant No. 2016YFC1000307), and the Project of National Research Institute for Family Planning (Grant No. 2018NRIFPJ03), People's Republic of China. The authors have no conflicts of interest to declare. TRIAL REGISTRATION NUMBER N/A. [ABSTRACT FROM AUTHOR]

In insects, aging produces deterioration in physiological and cellular functioning, affecting their reproductive potential. Anastrepha fraterculus and Ceratitis capitata are two fruit fly species where overwintering adults resume their reproductive activity in spring, giving old individuals the possibility of mating with young adults. Most age studies focus on male reproductive capacity; however, we lack information on how the interaction between the ages of both sexes can determine post‐mating processes. Here, we studied sex and age effects on (i) female fecundity and fertility, (ii) failure to leave viable offspring (reproductive failure), and (iii) female remating behavior. We found that young pairs of both species had higher fecundity, but young C. capitata males mated with old females had the lowest fecundity. This suggests that overwintering flies in this species will not substantially contribute to the next generation. We also found in C. capitata more prevalent reproductive failure in hetero‐age combinations, which could be due to age recognition between mates, resulting perhaps in differential ejaculate allocation. Copula duration was positively associated with female age, yet it was longer for older A. fraterculus females and shorter for C. capitata females. Female remating was lower when young females mated with old males in C. capitata. This would imply that males perceive young females of "good quality" and thus invest and transfer all the ejaculate possible to ensure the delay of renewal of female receptivity. Aging does not always cause a decline in reproductive potential, which may be important in species that overwinter as adults. Complex interactions between female physiology and male ejaculate senescence can impact postcopulatory behaviors that affect reproductive success for both sexes. [ABSTRACT FROM AUTHOR]

Consumption of a high-fat diet is accompanied by the risks of obesity and early onset of age-associated complications for which dietary interventions are imperative to combat. α-lipoic acid has been shown to hinder diet-induced obesity and induce lifespan-extending efficacy in model organisms. In this study, α-lipoic acid was investigated for its efficacy in improving lifespan and stress resistance in the Canton-S strain of Drosophila melanogaster fed with a high-fat diet. Furthermore, as mating status significantly impacts survival in fruit flies, flies were reared in two experimental groups—group one, in which males and females were bred together, and group two, in which males and females were bred separately. In group one, α-lipoic acid improved the mean lifespan, reduced the fecundity of females, and reduced the mean body weight of flies at a dose range of 2–2.5 mM, respectively. In group two, α-lipoic acid improved the mean lifespan, reduced the fecundity of females, and reduced the mean body weight of flies at a dose range of 1–2.5 mM, respectively. Improved climbing efficiency was observed with α-lipoic acid at the dose range of 1.5–2.5 mM in flies of group one and 1–2.5 mM in flies of group two, respectively. Administration of α-lipoic acid improved resistance to oxidative stress in only female flies of group one at 2.5 mM, whereas in group two, both male and female flies exhibited enhanced resistance to oxidative stress with α-lipoic acid at a dose range of 2–2.5 mM, respectively. Male and female flies of only group one showed improved resistance to heat shock stress with α-lipoic acid at a dose range of 2–2.5 mM. Only female flies of group two exhibited a slight improvement in recovery time following cold shock with α-lipoic acid only at 2.5 mM. No significant change in resistance to starvation stress was observed with any dose of α-lipoic acid in either group of flies. To summarize, data from this study suggested a probable dose and gender-dependent efficacy of α-lipoic acid in flies fed with a high-fat diet, which was significantly influenced by the mating status of flies due to varied rearing conditions. [ABSTRACT FROM AUTHOR]

BACKGROUND: Controlling the spread of arboviral diseases remains a considerable challenge due to the rapid development of insecticide resistance in Aedes mosquitoes. This study evaluated the effects of boric acid‐containing toxic sugar bait (TSB) on field populations of resistant Aedes aegypti mosquitoes. In addition, this study examined the flight activity and wing beat frequency and amplitude of males and the flight activity, fecundity, and insemination of females after pairing with males exposed to TSB. The population dynamics of Aedes mosquitoes under imbalanced sex ratios were examined to simulate realistic field conditions for male suppression under the effect of TSB. RESULTS: The mortality of male mosquitoes was consistently high within 24 h after exposure. By contrast, the mortality of female mosquitoes was inconsistent, with over 70% mortality observed at 168 h. The flight activity and wing beat amplitude of treated males were significantly lower than those of controls, but no significant difference in wing beat frequency was detected. The fecundity and insemination of treated female mosquitoes were lower than those of controls. A simulation study indicated that considerably low male population densities led to mating failures, triggering a mate‐finding Allee effect and resulting in persistently low population levels. CONCLUSION: Boric acid‐containing TSB could effectively complement current chemical intervention approaches to control resistant mosquito populations. TSB is effective in reducing field male populations and impairing male flight activity and female‐seeking behavior, resulting in decreased fecundity and insemination. Male suppression due to TSB potentially results in a small mosquito population. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Inbreeding depression is predicted to increase with age, because natural selection is less efficient at purging deleterious alleles that are only expressed later in life. However, empirical results are scarce, and equivocal between studies. Here we performed controlled matings between related and unrelated individuals of domesticated Japanese quail (Coturnix japonica), and monitored the performance of their offspring for all fitness components over their complete life course. We found rapid senescence in adult survival and egg laying performance, and inbreeding depression at all life stages (reduced embryo viability, increased age at maturity, as well as reduced adult survival and reproduction). Inbreeding depression did not increase at later ages for survival, but did so for egg laying, thereby accelerating reproductive senescence. Moreover, the effect of inbreeding on egg laying persisted after correcting for lifespan, indicating that both survival and reproduction were independently affected by inbreeding. We suggest that in heterogeneous populations intra‐generational purging may at earlier ages already select out the individuals that are homozygous for the specific alleles responsible for depressed survival, preventing the appearance of increased inbreeding depression in survival with age. Given that inbreeding affects reproduction independent of survival this should not apply to reproductive senescence or homogeneous populations, which may explain equivocal results between traits and studies. [ABSTRACT FROM AUTHOR]

Understanding population dynamics requires estimation of demographic parameters like mortality and productivity. Because obtaining the necessary data for such parameters can be labour‐intensive in the field, alternative approaches that estimate demographic parameters from existing data can be useful. High‐resolution biologging data are frequently available for large‐bodied bird species and can be used to estimate survival and productivity. We extend existing approaches and present a freely available tool (‘NestTool') that uses GPS tracking data at hourly resolution to estimate important productivity parameters such as home range establishment, breeding initiation, and breeding success. NestTool first extracts 42 movement metrics such as time spent within a user‐specified radius, number of revisits, home range size, and distances between most frequently used day and night locations from the raw tracking data for each individual breeding season. These variables are then used in three independent random forest models to predict whether individuals exhibited home range behaviour, initiated a nesting attempt, and successfully raised fledglings. We demonstrate the use of NestTool by training models with data from 258 individual red kites Milvus milvus from Switzerland tracked for up to 7 years, and then applied those models to tracking data from different red kite populations in Germany where detailed observations of nests and their outcomes existed for validation. The models achieved > 90% accurate classification of home range and nesting behaviour in validation data, but slightly lower (80–90%) accuracy in classifying the outcome of nesting attempts, because some individuals frequently returned to nests despite having failed. NestTool provides a graphical user interface that allows users to manually annotate individual seasons for which model predictions exceed a user‐defined threshold of uncertainty. NestTool will facilitate the estimation of demographic parameters from tracking data to inform population assessments, and we encourage ornithologists to test NestTool for different species. [ABSTRACT FROM AUTHOR]

Invasive species present a serious peril to aquatic ecosystems worldwide, thus it is essential to have a comprehensive understanding of the reproductive dynamics, spreading characteristics, and biological properties of these species in order to effectively manage their population structure and mitigate both the ecological damage and economic loss they can cause. For this reason, we delved into the reproductive dynamics of Pseudorasbora parva, an invasive species of inland water fish found in Türkiye. We focused on three populations inhabiting Beyşehir (Konya, Isparta) and Eğirdir Lakes (Isparta) and Onaç Reservoir (Burdur). Sampling was carried out on a monthly basis from March 2021 to June 2022, utilizing a variety of tools such as multimesh nets, seine nets, and electrofishing. The developmental stages of gonads and reproductive cells were determined through morphological and microscopic examinations. A total of 1186 P. parva individuals were captured from all three lakes. Our results showed that the Beyşehir Lake population spawned from March to July, while the Eğirdir Lake population did so between May and October, and the Onaç Reservoir population laid their eggs from June to August. Female individuals in Beyşehir Lake, Eğirdir Lake, and Onaç Reservoir had initial breeding lengths of 3.49, 4.89, and 5.35 cm, respectively. In comparison, male individuals measured 5.56, 4.80, and 5.40 cm. Interestingly, the Beyşehir Lake population exhibited the highest egg fecundity, with each individual at 2 years producing a remarkable 2949 eggs. The present findings provide valuable information for us to further understand the reproductive biology and dynamics of P. parva, which could be useful in managing and preventing the spread of this invasive species in inland aquatic ecosystems. [ABSTRACT FROM AUTHOR]

Male‐biased sexual size dimorphism (SSD) is common in ungulates. The dominant scenario for the evolution of ungulate SSD suggests that habitat openness leads to greater SSD by increasing group size and thus sexual selection through male–male competition for mates. At a more proximate level, adaptive changes in SSD may result from the plastic response of individuals to environmental variation. In this study, we used 161,948 body mass data from a seasonally size‐dimorphic species, the northern chamois Rupicapra rupicapra, to examine the role of forest cover and other environmental variables in the expression of SSD. Data were collected from individuals hunted in the Austrian Alps, grouped into 28 mountain ranges with different forest cover, geological substrate and population density. Population‐specific growth curves were fitted using monomolecular models, and SSD was calculated as the log‐transformed ratio of male to female asymptotic body mass. A path model in which environmental factors indirectly influenced SSD via male or female body mass suggested that SSD increased with increasing density via reduced female body mass and decreased on siliceous substrates via reduced male body mass. Forest cover was negatively associated with body mass in both sexes, but not with variation in SSD. [ABSTRACT FROM AUTHOR]

Simple Summary: In this study, we used the vinegar fly, Drosophila melanogaster, as a genetic model to investigate the potential long-lasting consequences of exposure to paracetamol—a molecule found in common and widely used over-the-counter medicine for pain and fever relief. We found that increasing doses in the food of developing flies led to increasing mortality. Furthermore, we found that genetically distinct cultures of vinegar flies responded differently to paracetamol exposure when testing life span, spontaneous activity, and production of offspring for two different doses of the drug. These effects were not only present in the individuals directly exposed to the drug but also in the offspring and grand-offspring of these flies, showing the generational effects of the drug. The responses were highly complex and depended on generation after exposure, dose, and individual fly culture. Further investigations into the potentially long-lasting effects of paracetamol exposure and its possible relevance in humans are warranted, as generational effects of pharmaceutical drugs might have consequences for our future generations that are currently overlooked. Few investigations have been made to determine whether pharmaceutical drugs cause any generational effects. These effects can be divided into intergenerational and transgenerational effects. In insects, the F1 offspring of exposed individuals are considered to show intergenerational effects (as they have been exposed as germ cells or early embryos), while the F2 generation is fully non-exposed and considered to show transgenerational effects. Here, the common over-the-counter (OTC) drug, paracetamol, is investigated for genotype-specific responses and effects across generations on three life-history traits: fecundity, longevity, and spontaneous locomotor activity levels in the model species Drosophila melanogaster. Seven isofemale D. melanogaster lines were exposed to a high and intermediate dose of paracetamol determined by a dose–response curve. NMR investigations verified the long-term presence of paracetamol in the food substrate. Phenotypic effects of paracetamol ingestion were investigated on flies exposed to the drug and in their offspring and grand-offspring. The dose–response curve indicated genotype-specific responses to paracetamol. In the following experiment, all traits investigated displayed significant effects of paracetamol ingestion for at least one of the seven isofemale lines, and we detected strong genotype-specific responses to paracetamol. Fecundity tended to increase in individuals directly exposed to the drug whereas fecundity in the F2 generation was reduced (transgenerational). Longevity generally decreased in directly exposed individuals but tended to increase in F1 offspring (intergenerational). Paracetamol effects on spontaneous locomotor activity were primarily detected as transgenerational effects and were rarely seen in directly exposed individuals. However, across lines, no clear overall trend could be determined for any trait. The generational effects and marked genotype-specific response to paracetamol warrants further investigation of both genotype-specific responses and generational effects in general. [ABSTRACT FROM AUTHOR]

Spermatogenesis and sperm maturation that occur in the testis and epididymis respectively are crucial for fertility. Factors secreted by the testicular and epididymal epithelial cells govern the processes of gametogenesis and maturation. Proteins encoded by the sperm‐associated antigen 11a (Spag11a) gene are implicated as having a possible role in sperm maturation. However, studies that demonstrate their definite role in fertility and sperm function using knockout models have not yet reported. In this study, Spag11a knockout mice were generated, genotyped and the reproductive parameters (fecundity, sperm count, capacitation, and acrosome reaction) and sperm proteome were determined. Litter size and sperm count were decreased in the Spag11a knockout mice when compared to the wild‐type controls. Spermatozoa from the knockout mice were able to undergo capacitation. However, acrosome reaction did not occur in sperm obtained from knockout mice. Structural abnormalities in the head and tail structures were evident in the spermatozoa of knockout mice. Perturbations in the expression of sperm proteins that are involved in gametogenesis were evident. The subfertility observed in Spag11a knockout mice could be a manifestation of lower sperm count, impaired acrosome reactions, and disturbances in the sperm proteome. The results of this study lend further support to the role of Spag11a gene in male gamete function. Summary: Analyzing the role of male reproductive tract‐specific proteins in male fertility using knockout models is an active area of investigation. Although a large number of knockout models for genes that are specific to the testis are generated and the reproductive function studied, there are very few studies that analyze the role of epididymal proteins that contribute to sperm function and fecundity. In this study, the effect of knockout of an epididymal‐specific gene, Spag11a, on male reproductive function, especially the fecundity, capacitation, acrosome reaction, and sperm proteome was analyzed. Our observations indicate subfertility and compromised sperm function associated with perturbations in sperm proteome. Using shRNA‐mediated Spag11a mRNA ablation and active immunization‐mediated SPAG11A protein ablation, we previously demonstrated the possible role of Spag11a in sperm function and fecundity. This study significantly differs from our previous studies because we used a higher level of gene ablation model, that is, the Spag11a knockout mice to provide further evidence. Furthermore, we also analyzed the molecular changes at the proteome level under conditions of Spag11a gene knockout. Thus, this study carried a lot of significance since it reiterates the observations made in our previous studies using an animal model that truly reflects the ablation of Spag11a expression. [ABSTRACT FROM AUTHOR]

In this research, we aimed to determine the antioxidant activity of an atomized extract of Cnidoscolus diacanthus (Pax & K. Hoffm.) J.F. Macbr., known in Peru as "huanarpo hembra", and its effect on sex hormone levels. Its phytochemical profile was determined using liquid chromatography–mass spectrometry (LC–MS), while its total phenol content (TPC) and total flavonoids (TFs) were determined using the Folin–Ciocalteu method and the aluminum chloride method. Its antioxidant activity was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH), the radical 2,2-azino-bis-3-ethylbenzthiazolin-6 sulfonic acid (ABTS), and ferric-reducing antioxidant power (FRAP). The biological activity of C. diacanthus and its effect on sexual hormones were determined in Holtzman rats of both sexes. Phytochemical analysis revealed the presence of flavonoids and phenolic compounds in its leaves and stems, mainly rutin, quercetin, chlorogenic acid, and genistein. However, the stem extract contained higher total phenol (464.38 ± 4.40 GAE/g) and flavonoid (369.17 ± 3.16 mg QE/g of extract) contents than the leaf extract (212.38 ± 3.19 mg GAE/g and 121.49 ± 2.69 mg QE/g). For DPPH, ABTS, and FRAP, the Trolox-equivalent antioxidant capacity (TEAC) was 597.20 ± 5.40 µmol/g, 452.67 ± 5.76 µmol/g, and 535.91 ± 1.56 µmol/g, respectively, for the stems, while for the leaves, it was 462.39 ± 3.99 µmol/g, 202.32 ± 5.20 µmol/g, and 198.13 ± 1.44 µmol/g, respectively. In terms of the values for hormonal levels, at a dose of 100 mg/kg of the extract, testosterone levels of 1.430 ng/mL (with the leaf extract) and 1.433 ng/mL (with the stem extract), respectively, were found in the male rats. Regarding estradiol levels, in the female rats, these were 10.425 ng/mL (leaf extract) and 8.775 ng/mL (stem extract), while their levels of luteinizing hormone were 0.320 mIU/mL (leaf extract) and 0.273 mIU/mL (stem extract). For the follicle-stimulating hormone, levels of 0.858 mIU/mL (leaf extract) and 0.840 mIU/mL (stem extract) were found in the female rats, and levels of 0.220 mIU/mL (leaf extract) and 0.200 mIU/mL (stem extract) were found in the male rats. It is concluded that the C. diacanthus stem extract had a greater antioxidant capacity than the leaf extract, while both extracts had a superior effect on the sex hormone levels in the female rats compared to the male rats. [ABSTRACT FROM AUTHOR]

Sperm function is suggested to evolve by sexual selection but is also reduced by microbial damage. Here, we provide experimental evidence that male fertility can adapt to microbes. We found that in vivo, male fertility was reduced by one-fifth if sperm encountered microbes in the females that they had not previously been exposed to, compared to sperm from males that coevolved with these microbes. The female immune system activation reduced male fertility by an additional 13 percentage points. For noncoevolved males, fertility was larger if microbes were injected into females after they had stored away the sperm, indicating microbial protection as a previously unrecognized benefit of female sperm storage. Both medical and evolutionary research on reproductive health and fertility will benefit from considering our findings that the impact of microbes on sperm depends on their joint evolutionary history. Our results may assist in reconciling contradictory results of sexually transmitted disease effects on sperm and bring empirical realism to a recently proposed role of locally adapted reproductive microbiomes to speciation. [ABSTRACT FROM AUTHOR]

Fat body metabolism plays crucial roles in each aspect of insect life traits. Although neuropeptides have been documented to be one of the major neuroendocrinal regulators involved in fat body metabolism, the detailed regulatory mechanism is poorly explored. Here, we conducted comparative metabolome and transcriptome analyses of fat body between wide type (WT) and adipokinetic hormone/corazonin‐related peptide (ACP) loss of function mutants of the migratory locust, Locusta migratoria. We found that knockout of ACP resulted in significantly reduced fat body triacylglycerol content but enhanced abundance of phospholipids, particularly phosphatidylcholine and phosphatidylethanolamine. Additionally, the expression levels of genes involved in triacylglycerol and phospholipid synthesis and degradation were significantly altered in the fat body of ACP mutants. Moreover, female ACP mutants displayed much higher fecundity compared to WT females. These findings highlight the important role of neuropeptide ACP in fat body lipid metabolism homeostasis in locusts. [ABSTRACT FROM AUTHOR]

Springtails are a very common, widely spread component of soil fauna that play a significant role in numerous physical, chemical, and biological processes in the soil. Therefore, it is important to understand how their evolution and demographic parameters have changed throughout time. Since salinity is a relevant condition in the soils around the World and particularly in Mexico, the major goal of the current research is to understand the life cycle strategies of two springtail species from saline soils in Mexico. The studied species are Clavisotoma filifera and Brachystomella gabrielae, both widely distributed in Mexico, but their development or life history strategies are unknown. We found from laboratory cultures that C. filifera had a shorter life cycle and a faster reproduction rate than B. gabrielae. Nevertheless, both species show the same number of developmental stages, but there are interspecific differences in their duration. Although both species continuously reproduce throughout the year, the reproductive rate is lower in the months that are associated with the dry season at the source site. Additionally, we discovered variations in both the size and number of eggs in each species. It was found that the species under study had various life strategies for growth in the same environment. Clavisotoma filifera shows a more r-focused strategy (high fecundity, numerous offspring, shorter gestation and faster maturity), B. gabrielae shows an opposite strategy, closer to q strategy, with a lower fecundity, larger eggs, fewer reproductive events and slower maturity. [ABSTRACT FROM AUTHOR]

The intracellular pathogens Toxoplasma gondii, Brucella spp., and Chlamydia spp. are all known causative agents of abortion in wildlife. Both T. gondii and Brucella spp. have been identified in marine mammal abortions and a limited number of studies have detected their potential presence in Australian fur seals (Arctocephalus pusillus doriferus), but data are sparse for these pathogens in Australian fur seal breeding colonies. Australian fur seals have been shown to have a high degree of third-trimester pregnancy loss in one of their largest breeding colonies. Additionally, pup production has declined at the largest breeding colony for the species. This study surveyed the presence of T. gondii, Brucella spp., and Chlamydia spp. as potential infectious causes of this reproductive loss. Aborted fetuses were collected from two of the largest breeding colonies for the species, Seal Rocks (n=19) and Kanowna Island (n=34). These were examined grossly and through histopathological evaluation, in conjunction with molecular testing for all three pathogens. Placentas were collected from full-term births during the pupping season from Kanowna Island (n=118). These were used to compare the molecular prevalence of the three pathogens in presumed successful pregnancies. Chlamydia spp. was not detected in aborted fetuses in this study. Brucella spp. was detected with PCR in both aborted fetuses (9.4%) and placentas from full-term births (3.4%), and T. gondii was detected using routine histopathology (n=2/53), immunohistochemistry (n=3/4), and PCR (n=4/53) in tissues from aborted fetuses. Toxoplasma gondii was present in 7.5% of third-trimester abortions and absent from all full-term placentas. Brucella spp. was detected in both aborted fetuses and full-term placentas. This is the first description of vertical transmission of T. gondii in a marine mammal from the southern hemisphere. [ABSTRACT FROM AUTHOR]

The spread of marine non-indigenous species (NIS) is driven largely by shipping and global trade. Biofouling on vessel hulls is a major source of invasions, but many biofouling organisms are sessile (non-motile) and require reproduction, which often produces mobile, waterborne propagules (e.g., larvae) that can colonize new regions. The ability of biofouling organisms to reproduce, however, can depend strongly on abiotic conditions at the time of reproduction but also potentially prior to any reproductive event. For many organisms, past environments can influence performance later in life via within-generation carryover effects, but how carryover effects influence potential NIS introductions is unclear. We conducted a laboratory experiment to explore within-generation carryover effects of salinity and how they operate across different environments in the barnacle Amphibalanus improvisus, a common biofouling organism. We exposed newly settled barnacles to two different salinities (15 and 28 psu) for three weeks, maintained them in a common salinity for five weeks, then re-exposed them to the two initial salinities in a fully-factorial design prior to measuring their reproductive output. We found that barnacles that switched salinities between the initial and final exposures tended to produce more nauplii larvae (up to 50%) than those that remained in the same salinity conditions, possibly because of a stress response induced by physiological acclimation to early life environments. Because adult biofouling species are likely to be exposed to variable environmental conditions during vessel transits, carryover effects and their impact on propagule output may be important to consider when evaluating potential NIS introductions via biofouling. [ABSTRACT FROM AUTHOR]

Apigenin is an organic flavonoid abundant in some plants such as parsley, chamomile, or celery. Recently, it has been investigated for several of its pharmacological characteristics, such as its ability to act as an antioxidant, reduce inflammation, and inhibit the growth of cancer cells. The purpose of this review is to provide a summary of the existing knowledge regarding the effects of apigenin on female reproductive systems and its dysfunctions. Apigenin can influence reproductive processes by regulating multiple biological events, including oxidative processes, cell proliferation, apoptosis, cell renewal and viability, ovarian blood supply, and the release of reproductive hormones. It could stimulate ovarian folliculogenesis, as well as ovarian and embryonal cell proliferation and viability, which can lead to an increase in fertility and influence the release of reproductive hormones, which may exert its effects on female reproductive health. Furthermore, apigenin could inhibit the activities of ovarian cancer cells and alleviate the pathological changes in the female reproductive system caused by environmental pollutants, harmful medications, cancer, polycystic ovarian syndrome, ischemia, as well as endometriosis. Therefore, apigenin may have potential as a biostimulator for female reproductive processes and as a therapeutic agent for certain reproductive diseases. [ABSTRACT FROM AUTHOR]

The gametogenic cycle in broadcast spawning corals takes several months, with oogenesis culminating in synchronized maturation when seawater temperatures rise. Temperature is known for governing reproductive seasonality, yet little is known about how multiple stressors may affect spawning timing. The semi-enclosed lagoon of Bouraké in New Caledonia is subjected to high fluctuations in seawater temperature, pH, salinity, and oxygen, representing an ideal playground to explore possible effects of extreme environmental variability on coral gametogenesis. Here, the spawning window and fecundity metrics (i.e., colony- and polyp-level fecundity, and egg size) of Acropora tenuis, Montipora digitata, and M. stellata from Bouraké were compared with four reference sites located at variable distances from Bouraké. Results suggest that Bouraké and its nearby control site largely spawned synchronously, but there was a spawning asynchrony between Bouraké and the sites further south, in all three species. Interestingly, no reduction in the number of eggs per fecund polyp or number of fecund polyps was observed in Bouraké compared with the reference sites, in any species. However, A. tenuis and M. digitata had smaller eggs in Bouraké compared to reference sites, with possible repercussions for coral fitness. In conclusion, some reproductive traits are maintained in coral species inhabiting a highly variable environment, but smaller gametes may alter population recovery processes. Furthermore, since our data are limited to 2 yrs of observations, spawning synchronization between Bouraké and its surroundings warrant continued investigation to determine whether coral colonies from this area harbor traits that increase fitness under future climate scenarios. [ABSTRACT FROM AUTHOR]

The American hoverfly Eupeodes americanus (Wiedemann) (Diptera: Syrphidae) is an aphidophagous predator during its larval stage and is currently being evaluated for inclusion in biocontrol programs as a new biocontrol agent. However, little is known about its reproductive aptitudes. The objective of the present study was to determine the reproductive parameters of E. americanus and to compare them with those of a commercialized and widely used biological control agent for aphids, the aphid midge Aphidoletes aphidimyza (Rondani) (Diptera: Cecidomyiidae). The preoviposition period, oviposition period, adult longevity, lifetime and daily fecundity, egg hatching rate, and fertility were determined for E. americanus females and compared to those of A. aphidimyza. Trials were conducted under laboratory conditions in rearing cages on the broad bean plant Vicia faba L. (Fabaceae), infested with pea aphids Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae). The results revealed that the preoviposition period, oviposition period, and adult longevity were significantly longer in E. americanus than in A. aphidimyza. The daily fecundity and egg-hatching rate were similar in both species. However, lifetime fecundity and fertility were considerably higher in E. americanus than in A. aphidimyza. This study demonstrates that the reproductive capacity of E. americanus is clearly superior to that of A. aphidimyza and therefore supports its inclusion in the aphid pest management program as a new biocontrol agent. [ABSTRACT FROM AUTHOR]

Climate change is driving both higher mean temperatures and a greater likelihood of heatwaves, which are becoming longer and more intense. Previous work has looked at these two types of thermal stressors in isolation, focusing on the effects of either a small, long-term increase in temperature or a large, short-term increase in temperature. Yet, a fundamental gap in our understanding is the combined effect of chronic and acute thermal stressors and, in particular, its impact on vital processes such as reproduction. Here, we investigated the independent and interactive effects of higher constant temperatures and short-term heatwave events on reproductive success and offspring fitness in an insect study system, the burying beetle Nicrophorus vespilloides. We found a substantial reduction in key fitness traits (fecundity, hatching success and offspring size) after exposure to both a heatwave and higher constant temperatures, but not after exposure to only one of these thermal stressors. This indicates that the effects of chronic and acute thermal stressors are amplified when they act in combination, as is very likely to occur in natural populations. Our findings, therefore, suggest that, by not considering the potential multiplicative effects of different types of thermal stressors, we may be underestimating the effects of climate change on animal fertility. [ABSTRACT FROM AUTHOR]

Corn- and soybean-dominated cropping systems create and maintain a favorable environment for summer annual weeds whose emergence and growth phenology are similar to these annual summer crops. Cropping system diversification can be an effective approach for controlling noxious weeds without increasing reliance on chemical herbicides. Diversification may be especially important for managing waterhemp, a dioecious, summer annual weed that is becoming increasingly prevalent in the US Corn Belt due to its life history characteristics and herbicide resistance profile. Compared to corn and soybean, alfalfa and oat emerge and establish earlier and are thus more competitive with warm-season weeds like waterhemp. Knowledge of vegetative and reproductive characteristics in a range of crop environments can be valuable for planning weed management strategies. However, most of the relevant characteristics for a population dynamics model were available in corn and soybean monocultures. We examined the relationship between waterhemp's abovegroundmass and fecundity under four crop species' presence within three crop rotation systems: a 2-year sequence of corn and soybean; a 3-year sequence of corn, soybean, and oat intercropped with red clover; and a 4-year sequence of corn, soybean, oat intercropped with alfalfa, and alfalfa. All the rotation systems were treated with conventional or reduced rates of herbicides. We established eighteen linear equations to predict waterhemp's fecundity from dried aboveground mass in each crop and associated crop management program since measuring the latter allows for quicker estimation of fecundity compared to counting seeds on each individual plant. Rotation system and crop phase within rotation system had significant effects on all the response variables but weed control regime on some. The sex ratios at maturity were slightly female-biased in oat and alfalfa. Mature waterhemp plants were larger in corn and soybean than in oat and alfalfa. Oat and alfalfa were planted earlier than corn and soybean and successfully competed for resources against waterhemp despite the absence of herbicide or interrow cultivation. Frequent hay cuts in alfalfa served as physical weed control and contributed to suppressing waterhemp and other weeds substantially. [ABSTRACT FROM AUTHOR]

Leadbeater's possums (Gymnobelideus leadbeateri) are a critically endangered marsupial found in a restricted area of cold, wet forest in South‐Eastern Australia. The majority of Leadbeater's possums inhabit highland forest, with one outlying lowland population. In 2012, a breeding program was established for the lowland Leadbeater's possums when this genetically distinct population faced imminent extinction. Successful reproduction by highland Leadbeater's possums in the international zoo‐based population between 1970 and 2010 led to the widespread belief that the species bred readily in captivity. Lowland possums have not bred in the 2012–2021 contemporary captive conservation breeding program. This study reviewed the historic captive‐breeding data and found that of the 84% (162/194) that reached reproductive maturity; 37% of males (n = 30) and 39.5% of females (n = 32) bred, and this success was highly skewed towards a subset of highly fecund individuals (14% of females and 15% of males produced 75% and 80% of all offspring). Although lack of reproductive output in the captive lowland animals could be explained if age at mortality was lower than that of highlands possums, comparison of the longevity of highland and lowland animals had no significant difference. Conservation objectives that specify how captive breeding may support in situ recovery of wild populations are integral to the success of captive programs. A lack of reflective analysis of past husbandry records allowed misconceptions of success and approaches implemented in the management of the breeding program, reducing the benefits for the conservation of this high profile threatened species. This case study provides a lesson for the management of conservation breeding programs and illustrates the importance of well‐defined conservation objectives, integration of in situ and ex situ strategies, and the importance of objective, systematic and timely analysis of available evidence to inform management objectives and improve conservation outcomes in real time. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the effect of vitamin E on the reproductive responses and the expression of reproductive genes in butter catfish (Ompok bimaculatus). Diets with different levels of vitamin E supplementation (0, 100, and 150 mg/kg) were provided to groups of fish for 60 days. After rearing for 60 days fish were induced with synthetic hormone, that is, Ovatide to study the breeding performance. Ovatide was administrated intramuscularly at the rate of 0.5 and 0.25 mL/kg of body weight for females and males, respectively, in all the treatments. Breeding performance result shows that supplements of vitamin E positively influenced the GSI%, fertilization rate, fecundity, and hatching rate. To understand the relationship between vitamin E and the breeding performance of the fish at the molecular level, a gene expression study was conducted. This study employed real‐time PCR for the selected genes critical for reproductive function. In the brain, testis, and ovary dietary vitamin E supplementation of 100 mg/kg significantly enhanced the mRNA transcription of FSHR, Brdt, ESR1, 17beta2, and LHR. Hence, it can be said that 100 mg/kg of vitamin E supplementation in the diet during the reproductive period of O. bimaculatus could improve breeding performance and the mRNA expression of reproductive hormone receptor genes in both males and females of O. bimaculatus. [ABSTRACT FROM AUTHOR]

The features of the physical environment set the stage upon which sexual selection operates, and consequently can have a significant impact on variation in realized individual fitness, and influence a population's evolutionary trajectory. This phenomenon has been explored empirically in several studies using fruit flies (Drosophila melanogaster) which have found that changing the spatial complexity of the mating environment influenced male–female interaction dynamics, (re)mating rates, and realized female fecundities. However, these studies did not explore mating patterns, which can dramatically alter the genetic composition of the next generation, and frequently only compared a single, small "simple" environment to a single larger "complex" environment. While these studies have shown that broadly changing the characteristics of the environment can have big effects on reproductive dynamics, the plasticity of this outcome to more subtle changes has not been extensively explored. Our study set out to compare patterns of mating and courtship between large- and small-bodied males and females, and female fecundities in both a simple environment and 2 distinctly different spatially complex environments. We found that realized offspring production patterns differed dramatically between all 3 environments, indicating that the effects of increasing spatial complexity on mating outcomes are sensitive to the specific type of environmental complexity. Furthermore, we observed female fecundities were higher for flies in both complex environments compared those in the simple environment, supporting its role as a mediator of sexual conflict. Together, these results show that the union of gametes within a population can be greatly influenced by the specific spatial features of the environment and that while some outcomes of increased environmental complexity are likely generalizable, other phenomena such as mating patterns and courtship rates may vary from one complex environment to another. Graphical Abstract [ABSTRACT FROM AUTHOR]

The efficient conversion of tissues into reproductive success is a crucial aspect affecting the evolution of life histories. Masting, the interannually variable and synchronous seed production in perennial plants, is a strategy that can enhance reproductive efficiency by mitigating seed predation and pollen limitation. However, evaluating benefits is insufficient to establish whether efficiency has improved, as such assessments neglect the associated costs of masting, particularly during the critical seed‐to‐seedling stage. We conducted a parentage analysis of seedlings and adults in a population of 209 Sorbus aucuparia trees, monitored over 23 years, providing pioneering documentation of the effects of masting on the fitness of individual trees beyond the seed stage. Our results show high costs of interannual variation that can be mitigated by high synchrony and reveal the existence of phenotypes that appear to reap the benefits of masting while avoiding its costs through regular reproduction. [ABSTRACT FROM AUTHOR]

Polyphagy is an adaptative strategy allowing species to develop and survive on multiple diets. Phytophagous insects can be exposed to sub-optimal resources, as host plants vary in nutritional quality. Some insects may rely on symbiotic bacteria to better utilize less favorable substrates. The invasive fruit fly Drosophila suzukii is a highly successful pest worldwide. The use of ripening and ripe fruits, a niche neglected by other drosophilids, and its polyphagy may have contributed to its global spread. The role of D. suzukii's Wolbachia strain (wSuz) remains unconfirmed, although a mutualistic role has been hypothesized via virus protection or dealing with abiotic stress. In some insect species, Wolbachia acts as a nutritional mutualist. This study explored the role of wSuz in D. suzukii adaptation to fluctuating diet regimes. To simulate a diet shift, we used Wolbachia-infected and uninfected flies, maintained on a corn-based (low-starch) or a grape-based (high-starch) diet for at least 10 generations. Then, we placed individuals from each line on one or the other diet for 30 days. The effects of Wolbachia and the diet treatments were assessed by quantifying female fecundity, egg-to-adult development time and survival, and offspring mass. The presence of Wolbachia positively affected female fecundity and offspring mass after a diet shift. Wolbachia also increased survival during larval development regardless of the diet, supporting its mutualistic role. Our results underline the role of wSuz on D. suzukii diet tolerance and performance. A better understanding of the role of symbionts in invasive species could help to improve management strategies. [ABSTRACT FROM AUTHOR]

The first aim of this study was to test the pulsed stress hypothesis on a system consisting of young spring wheat (Triticum aestivum L.) and the rose-grain aphid Metopolophium dirhodum (Walker) by following the age-stage, two-sex life table theory. This hypothesis predicts that fluid-feeding insects benefit from feeding on plants intermittently stressed by drought due to the increased nutrient availability and restored cell turgor. Our second aim was to illustrate the risk of drawing different conclusions if based on a single or a small subset of parameters or if the entire lifespan of a generation is not covered compared to if the study was conducted at the population level. We applied periods of drought stress (soil water capacity, SWC = 40%) on four occasions relative to the population development of the aphids and compared those treatments with well-watered (SWC = 70%) and continuous stress conditions (SWC = 40%). The timing of the stresses appeared to be important in determining the effect on aphid performance. Although we found some improvement in fecundity when the stress occurred before the aphids were placed on the plants, the overall effect of the early-timed pulsed stress treatments on the rate of increase was negative compared to the well-watered control, which was mainly due to prolonged nymph development. The drought pulse that was timed late (the second week of aphid reproduction) did not show any effect relative to the well-watered control. This study therefore provides no clear support for the validity of the pulsed stress hypothesis. [ABSTRACT FROM AUTHOR]

Simple Summary: Lampreys are a group of about 40 species found all over the world. One representative of this group is the river lamprey, which spends its larvae life initially in fresh water and then in the sea. For spawning, which is the end of their last migration, they return to fresh water. The spawning migration period lasts many months, during which the lampreys do not eat and many changes occur in their bodies. However, knowledge of these processes and their dynamics has not been studied and described, and this is the basis for preparing programs for the restitution of lampreys and their artificial reproduction under controlled conditions. This paper describes the changes occurring during spawning migration in female river lampreys, including the development of ovaries, changes in the liver, and atrophy of the digestive system. More than 40 species of lampreys (Petromyzontiformes) are known worldwide. Some of them are parasitic and feed on the blood of fish or other aquatic animals. Lampreys spawn once in their lifetime, after which they die. One of the representatives of the ichthyofauna of European rivers is the river lamprey, Lampetra fluviatilis. The river lamprey is now an endangered species due to loss and degradation of their habitats. The present study investigated gonadal development without hormonal stimulation in female river lampreys during puberty under controlled conditions for a period of seven months. Female river lampreys were kept in conditions that mimicked the natural environment. During the November–May period, samples were taken monthly to determine the extent of gonadal development and gastrointestinal and liver changes using histological examination. From the results obtained, the dynamical changes were determined for the following: gonadosomatic index (GSI; %), hepatosomatic index (his; %), and digestivesomatic index (DSI; %). With the gonadal development of female lampreys, an increase in GSI (7–23%; November–May) and a decrease in DSI (0.4–0.1%; November–May) histological changes were observed in the gonads (oocyte development), intestines (over time, decreased lipid vacuoles and enterocyte apoptosis), and in the liver (decreased lipid vacuoles and hepatocyte apoptosis over time) and in the digestive system resulting from its degradation. Also, it was observed that there was a change in the color of the liver to green in April. This study demonstrated the key role of the liver in the oocyte maturation process in this species. [ABSTRACT FROM AUTHOR]

The insecticide flufenoxuron, one of the insect growth regulators used in pest control, has been presented as a viable alternative against several insects and mites by inhibiting chitin synthesis and leading to changes in the midgut epithelium. The current study aimed to examine whether flufenoxuron interferes with the structural organisation, weight, volume, fecundity and fertility of the male reproductive system of Spodoptera mauritia, a sporadic pest that occasionally inflicts significant losses to rice crops. Median effective dose (ED50) indicates that flufenoxuron is effective against S. mauritia, and the moulting inhibition percentage, when calculated with probit analysis, indicates that ED50 were 0.00068 µg for 144 h. Topical application of two selected doses (ED25 and ED50) was applied to find out the effects of flufenoxuron exposure on male gonadal development. The flufenoxuron treatment significantly impaired the organization and development of the testis follicles and other parameters like weight, volume and gonadosomatic index. Moreover, reductions in fecundity and fertility rate, 27.33 ± 13.86 and 85.36 ± 12 for treated male × untreated female, 47 ± 23.33 and 97.16 ± 22.92 for untreated male × treated female, and 4 ± 4 and zero for both treated pairs, were found in the emerged S. mauritia adult following the larval treatment, suggesting the occurrence of defects in reproductive organs in both male and female moths. These findings highlight the reproductive toxicity of flufenoxuron on the rice swarming caterpillar, offering insights into the male reproductive toxicity associated with chitin synthesis inhibition. The impairment of reproductive organ development suggests the potential use of flufenoxuron for controlling pest populations effectively. [ABSTRACT FROM AUTHOR]

Tea mosquito bug (TMB), Helopeltis theivora is a most serious pest on cocoa worldwide that inflicts huge economic losses under epidemic situations. Laboratory colonies are necessary to perform year-round research to develop suitable management strategies for this pest. This study aimed to establish a population of TMB on suitable cocoa-feeding substrates under laboratory conditions. We used green cocoa pods and tender shoots as a food substrate and compared the biological parameters of H. theivora between them. The adult females preferred to lay more eggs on pods (32.20 ± 1.86 eggs/female) either singly or in a small group, and low fecundity was observed on shoots (20.75 ± 1.16 eggs/female). Meanwhile, egg hatching was highest on pods (92.48 ± 2.91%) than on shoots (74.08 ± 3.73%). This pest consists of five nymphal instars and the total nymphal duration was 13.53 ± 1.26 and 14.73 ± 0.85 days on pods and shoots, respectively. In addition, the per cent survival of H. theivora was highest on pods (78.66 ± 3.46) and lowest on shoots (51.85 ± 2.33). Significant differences were recorded in adult longevity and the mean life span of males and females were 13.17 ± 1.58 and 16.63 ± 1.64 days on pods; 11.10 ± 1.41 and 14.36 ± 1.53 days on shoots, respectively. Further, females lived longer than males in both substrates. Although, TMB will survive both on pods and tender shoots; rearing on pods could be more suitable and reliable to establish a sizable population of H. theivora under laboratory conditions. [ABSTRACT FROM AUTHOR]

Background: Patients with familial adenomatous polyposis (FAP) experience psychological and social challenges concerning future events such as marriage and childbirth alongside the medical risks of colorectal cancer (CRC) and FAP-related disease. We retrospectively investigated the rate of marriage and childbirth postoperatively in Japanese patients with FAP. Methods: We included 161 patients who had colorectal surgery and reported marital status from a national survey of 35 Japanese institutions. Participants were classified according to marital status: married before colectomy (80 patients), married after colectomy (13 patients), and unmarried (68 patients). Results: The marriage rate for all 161 patients (57.8%, standardized ratio 0.95, 95% confidence interval [CI] 0.76–1.14) was comparable to that in the general Japanese population (57.1%). The marriage rate among the 81 patients who were unmarried before colectomy was low (16.0%); however, the standardized marital ratio (0.75, 95% CI 0.34–1.15) was not significantly lower than that of the general population. In multivariable logistic regression, younger age (born after 1980, odds ratio [OR] 0.12, p < 0.001) and genetic testing (OR 4.06, p = 0.001) were associated with postoperative marriage. Seventy-one percent of patients with FAP who married after colectomy became pregnant and achieved delivery. Conclusions: The marriage rate of patients with FAP was comparable to that of the general population whereas the rate after colectomy was low among patients with FAP. However, in patients with FAP, colorectal surgery itself may not lead to negative consequences in terms of fecundity. [ABSTRACT FROM AUTHOR]

Increased female age at mating is considered a detrimental factor on reproductive output and fitness in insects, even if the impact is rather species specific. The effect of delayed mating on reproductive output has been widely studied in pest species controlled with mating disruption, as if the method is not fully effective in suppressing matings, it could still delay them, limiting female fitness and pest damage. Female mating delay, however, may also occur in natural habitats without invoking mating disruption. We studied the effect of female delayed mating in Cerambyx welensii (Küster) (Coleoptera: Cerambycidae), an oak‐living sapro‐xylophagous longhorn beetle considered a critical factor in oak decline. Several life history and ecological traits may potentially delay mating, including low abundance, (re)colonisation processes, sexual communication channel, host‐produced kairomones, operational sex ratio, reproductive interference and adverse weather conditions. We conducted laboratory tests to assess the impact of mating delays (0‐, 10‐, 20‐ and 30‐day post‐emergence) on reproductive output. Data showed that mating delay until at least 20 days of age had a limited effect on mating success, lifetime fecundity, longevity and fertility. The daily fecundity pattern depended on mating delay, and virgin females showed ovarian retention. We conclude that C. welensii females have evolved physiological adaptations to overcome mating delays and optimise fitness. We discuss our results from an evolutionary perspective, considering specifically the risk of early predation and egg‐laying time limitation. We hypothesise that unpredictable recurrent stochastic variation in male availability could act as an additional driver selecting for synovigeny in this longhorn species. [ABSTRACT FROM AUTHOR]

This article presents the results of the study of ecological and biological characteristics of common carp (Cyprinus carpio Linnaeus, 1758) from Kapchagay Reservoir on the Ili River in Kazakhstan. We studied size-weight indices, body condition (Fulton condition factor), age structure, fecundity, and body length. We also determined the gonadosomatic index (GSI) during the spawning period. Fish samples were caught using fixed nets with mesh diameters ranging from 16 to 90 mm. Total body length (TL) in mm and total body weight (TW) of fish in grams were measured. A logistic regression model was used to determine body size at first maturity for females and males. Fecundity was determined in mature females (stage IV maturity). Calculation of the GSI made it possible to clarify the duration of the spawning period. This study provides important information about the troubling status of the population of C. carpio in the area of study and suggests effective approaches to regulate fisheries in the reservoir and other water bodies of Kazakhstan. There is clearly a need to limit IUU (illegal, unreported and unregulated) fishing and otherwise regulate over-fishing. [ABSTRACT FROM AUTHOR]

One of the Brachyura crabs found in the lower reaches of the Serayu River is Varuna litterata, also known as the "herring bow crab". This crab usually inhabits shallow tidal areas and hides under rocks, logs, or dead leaves. It is a highly adapted crab found in a wide range of salinities. V. litterata is also a fishery product consumed in Thailand, the Philippines, and Indonesia. This research was conducted in the Lower Serayu River, Central Java, which consists of three observation stations, namely: 1) the first station is located above the dam with fresh water, 2) the second station is below the dam with fresh water properties and 3) the third station is downstream (estuary) of the Serayu River with brackish water. This research was conducted for four months, from October 2023 to January 2024. This study aimed to determine the level of egg development in V. litterata. The results showed that V. litterata experienced four stages in egg development and then hatched into zoea. At the initial development stage, V. litterata eggs will be purple; in the second stage, the eggs will turn reddish; in the third development stage, the eggs will turn orange to brownish; and in the fourth stage, the eggs will develop and become black. V. litterata that will spawn will migrate to brackish waters to hatch their eggs. V. litterata produces 20,708 - 85,886 eggs with an average egg diameter of 0.440 - 0.466 mm. [ABSTRACT FROM AUTHOR]

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The presence of dams on the Columbia River (CR) has reduced Sockeye Salmon (Oncorhynchus nerka|sćwin) numbers to a fraction of their historic numbers. The Syilx Okanagan Nation Alliance (SONA) has led voices of concern regarding the impacts of diminishing Sockeye Salmon numbers on the ecosystem health of the sq,awsitkʷ|Okanagan River (s|OR), a tributary of the CR. In the early 2000s efforts commenced to rehabilitate the s|OR Sockeye population. These efforts have seen the population rise from a running average of 40,000 to 200,000. However, the contemporary spawning capacity of the s|OR is unknown, and this metric is critical to guide the conservation and restoration of this keystone species. We employed a spawning capacity model relating fish length and gravel size to spawning potential. We collected substrate data at 49 sites throughout our 37‐km study area, and used fish length and egg numbers from n = 269 Sockeye Salmon to establish s|OR specific fecundity metrics. The model estimated the s|OR has the capacity to support 147,687 (±33,346) Sockeye spawners, in its current condition. Whilst our model has limitations, we suggest a minimum escapement of 147,687 Sockeye spawners ought to be passed to the s|OR per annum. These fish will have broad ecosystem benefits and will be culturally beneficial to SONA peoples. Finally, continued restoration of s|OR habitat should enhance opportunities for Sockeye Salmon to continue their remarkable recovery. [ABSTRACT FROM AUTHOR]

BACKGROUND: Understanding how parasitoids respond to temperature is crucial for improving biological control strategies under the context of global warming. This study examined the suitability of Myzus persicae and its parasitoid Aphidius gifuensis to varying temperature conditions, as well as the stage‐specific response of A. gifuensis to high temperatures. RESULTS: High temperatures had a significant impact on the both M. persicae and A. gifuensis. When exposed to 36°C, M. persicae developed more slowly and produced smaller adults compared to control, regardless of the duration of exposure (2, 4 or 6 h); additionally, the survival rate of M. persicae nymphs sharply decreased under these conditions. Exposure to 36°C for 4 h negatively impacted the development of A. gifuensis. Female parasitoids exposed to 32°C developed into smaller adults, whereas males exposed to all three temperature levels were smaller compared to control group. Female parasitoids exposed to high temperatures, regardless of the specific heat level and duration, exhibited reduced longevity and decreased fecundity. None of the parasitoids exposed to 36°C for 6 h daily developed into adults. Heat treated during early developmental stages (2 and 4 days old) had a greater influence on parasitoid development, whereas heat treatment at 4 and 6 days old had a more significant impact on its fecundity. CONCLUSION: High temperatures not only directly affected the performance of A. gifuensis, but also exerted indirect effects by influencing the quality of the host aphids M. persicae. The deleterious effects of high temperature on larvae can persist into the adult stage, affecting the longevity and reproduction of adults. These findings are important for the utilization of A. gifuensis in the control of M. persicae in warming environments. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

BACKGROUND: Saliva has a crucial role in determining the compatibility between piercing–sucking insects and their hosts. The brown planthopper (BPH) Nilaparvata lugens, a notorious pest of rice in East and Southeast Asia, secretes gelling and watery saliva when feeding on rice sap. Nlsalivap‐5 (NlSP5) and Nlsalivap‐7 (NlSP7) were identified as potential planthopper‐specific gelling saliva components, but their biological functions remain unknown. RESULTS: Here, we showed by transcriptomic analyses that NlSP5 and NlSP7 were biasedly expressed in the salivary glands of BPHs. Using the clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9‐mediated genome‐editing system, we constructed NlSP5 and NlSP7 homozygous mutants (NlSP5−/− and NlSP7−/−). Electrical penetration graph assay showed that NlSP5−/− and NlSP7−/− mutants exhibited abnormal probing and feeding behaviors. Bioassays revealed that the loss‐of‐function of NlSP5 and NlSP7 significantly reduced the fitness of BPHs, with extended developmental duration, shortened lifespan, reduced weight, and impaired fecundity and hatching rates. CONCLUSION: These findings deepen our understanding of the BPH–host interaction and may provide potential targets for the management of rice planthoppers. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Biological information on Glyphocrangon spinicauda A. Milne-Edwards, 1881, a western Atlantic deep-sea armored shrimp, is scant. This species occurs in the Gulf of Mexico, but at low abundance, in the southern (Mexican) part. We obtained a sample of 203 G. spinicauda at depths of 244–455 m during a research cruise exploring the biota of the upper continental slope of the southeastern Gulf of Mexico, off the Yucatán Peninsula. We examined morphometric and allometric relationships of the shrimp as well as some reproductive traits based on the number and size of embryos. Sex ratio (1.4 females:1 male) differed significantly from unity. Females had significantly larger total length (TL) and total weight, but not carapace length (CL), than males, suggesting that females have proportionally larger abdomens. All morphometric relationships were significant for both sexes and most were linear. Relationships against CL were mostly isometric, but TL and rostral length exhibited negative allometry, i.e. a proportionally smaller increase with increasing CL. Brood size (BS) and embryo mass volume were linearly related with female size, but embryo development stage significantly affected BS, embryo size, embryo mass volume, and reproductive output. We found a significant, negative relationship between residuals of the number and size of embryos, suggesting a trade-off in embryo production. Although G. spinicauda is of no commercial value, it co-occurs with other species of potential interest. Our results can thus be useful to design management and conservation plans should fisheries for deep-sea resources eventually develop in the southern Gulf of Mexico. [ABSTRACT FROM AUTHOR]

Purpose. To carry out a retrospective analysis of changes in the state of the white Dniester crayfish population (Pontastacus eichwaldi bessarabicus Brodsky, 1967) in the Dniester estuary. To provide a description of its abundance and range in this water body. To analyze changes in the main biological characteristics of this species at the population level in the estuary. Methodology. The material for the study was collected from the catches of commerical fishing gear during the crayfish fishery in the Dniester estuary in the period from 2017 to 2021. A complete biological analysis of the obtained material was carried out in the laboratory of the Department of Aquatic Bioresources and Aquaculture of the Odessa State Ecological University (OSEU). The total length of crayfish, their weight, absolute and working fecundity of females, egg diameter, size and weight characteristics of larvae and juveniles were determined. The feeding of crayfish in ontogeny was studied. To assess the reproductive capacity of the crayfish population in the Dniester estuary, we used the coefficient of fecundity preservation Ki calculated on the basis of the obtained data. Statistical data processing was carried out using MS Excel spreadsheets. Findings. In 1950-2021, the range of ​​the population of the Dniester white crayfish in the Dniester estuary decreased from 13 to 7‒8 thousand hectares, and its total stock — up to 200±50 thousand individuals. At the same time, the average density of this crayfish was 17-18 ind. per hectare of the estuary. In recent years, more than 60% of the water area, in which the population of white Dniester crayfish is found in the estuary, is located within the Lower Dniester National Nature Park. In addition, the size and weight of crayfish in the estuary have decreased in recent years. For example, in the 1960s and 1970s, up to 40-45% of individuals were characterized by a length of 13.5-16.5 cm. In 2017, the modal group consisted of individuals with a length of 9-9.5 cm, and in 2019-2021 — 9.6-10.0 cm. The maximum size of crayfish in 2019-2021 was 14.5-15.0 cm (19‒20 cm in 1960-1970s). The reproductive capacity of the population also deteriorated. Absolute and working fecundity decreased. The Ki coefficient for the population of this species in the Dniester estuary in 2017–2018 was 0.63, and in 2020–2021 it was 0.53. This indicates a progressive decrease in the abundance of its population. Originality. For the first time in the last 25‒30 years, an assessment of the current state of the Dniester white crayfish population is given. The analysis of the available data indicates the progressive degradation of the population. A decrease in the range of distribution of this species in the estuary, a decrease in its size, the share of females in the population, and indicators of their fecundity were recorded. A decrease in the coefficient of preservation of fecundity Ki indicates a depressed state of the Dniester white crayfish population in the estuary, which threatens its further degradation. In recent years, catches of white Dniester crayfish in the Dniester estuary have decreased significantly. For example, the catch per fyke net does not exceed 1.0-2.0 kg, and the share of individuals of non-commercial size (up to 10 cm) has increased significantly. Practical Value. The research results allowed: providing an ecological and biological characterization of the state of the Dniester white crayfish population in the Dniester estuary; characterizing changes in the abundance and spatial distribution of crayfish in this water body; highlighting the peculiarities of its biology; determining the strategy of restoration and rational use of the natural population of crayfish, becoming an opportunity during the development of effective methods of its artificial reproduction.

The hemlock woolly adelgid (HWA), Adelges tsugae (Hemiptera: Adelgidae), is native to the Pacific Northwest and Asia and is an invasive insect in the eastern United States causing widespread decline in health and increased mortality of native eastern and Carolina hemlock. Laboratory experiments conducted at ambient field temperatures were done to determine the adult and larval feeding totals on HWA and fecundity of the introduced predators Laricobius nigrinus and L. osakensis, and the native L. rubidus (Coleoptera: Derodontidae). During the 22-week period when Laricobius spp. adults are active in Virginia, from early November until late March the total mean ($\bar{x}$ x ¯ ± SE) of HWA eggs, nymphs, and adults were projected to be consumed per L. nigrinus (33.8 ± 4.0), L. osakensis (33.2 ± 4.0), and L. rubidus (16.4 ± 2.5) adults. Laricobius osakensis (102.1 ± 13.7) and L. nigrinus (72.0 ± 10.5), oviposited a similar number of eggs while L. rubidus (24.5 ± 5.2) oviposited a lower number of eggs. Mean larval consumption of HWA progrediens eggs was: L. nigrinus (169.6 ± 7.1), L. osakensis (140.1 ± 8.7), and L. rubidus (135.8 ± 12.8). The mean egg production of HWA was 74.5 ± 2.2. Based on predation and fecundity totals, L. osakensis was predicted to have a greater impact in reducing the number of HWA progrediens eggs than L. nigrinus and L. rubidus. [ABSTRACT FROM AUTHOR]

Caloric intake can greatly affect many aspects of an organism's life. A deficiency of calories can lead to stress resulting in decreased fecundity, insufficient calories to maintain tissues and increased lifespan. Conversely, increasing caloric density increases fecundity and decreases lifespan. Despite decades of work exploring food quality and quantity on physiology in the model species Drosophila melanogaster Meigan 1830 (Diptera: Drosophilidae) and the melanogaster group in general, relatively little work explores the physiological responses to diet manipulation in other Drosophila species, like the obscura species group. Here, we looked at the effects of five different caloric densities (0.5×, 0.75×, 1.0×, 1.5× and 3.0×) on food intake, body weight, body fat, fecundity and longevity in D. pseudoobscura Frolova & Astaurov, 1929 (Diptera: Drosophilidae). Comparing longevity and fecundity across diets, we found that heavy caloric concentration (3.0×) decreases lifespan and that calorie restriction (0.5× and 0.75×) led to significant decreases in fecundity and body weight. However, calorie concentration did not significantly increase D. pseudoobscura body fat. By expanding our understanding of the physiological responses to diet stress to D. pseudoobscura, we establish the framework for comparative work across Drosophila species. With this information, we can then identify which physiological responses to diet manipulation might be most conserved and comparable across species. [ABSTRACT FROM AUTHOR]

Abstract Background Energy allocation between growth and reproduction determines puberty onset and fertility. In mammals, peripheral hormones such as leptin, insulin and ghrelin signal metabolic information to the higher centres controlling gonadotrophin-releasing hormone neurone activity. However, these observations could not be confirmed in lower vertebrates, suggesting that other factors may mediate the energetic trade-off between growth and reproduction. A bioinformatic and experimental study suggested co-regulation of the circadian clock, reproductive axis and growth-regulating genes in zebrafish. While loss-of-function of most of the identified co-regulated genes had no effect or only had mild effects on reproduction, no such information existed about the co-regulated somatostatin, well-known for its actions on growth and metabolism. Results We show that somatostatin signalling is pivotal in regulating fecundity and metabolism. Knock-out of zebrafish somatostatin 1.1 (sst1.1) and somatostatin 1.2 (sst1.2) caused a 20–30% increase in embryonic primordial germ cells, and sst1.2 −/− adults laid 40% more eggs than their wild-type siblings. The sst1.1 −/− and sst1.2 −/− mutants had divergent metabolic phenotypes: the former had 25% more pancreatic α-cells, were hyperglycaemic and glucose intolerant, and had increased adipocyte mass; the latter had 25% more pancreatic β-cells, improved glucose clearance and reduced adipocyte mass. Conclusions We conclude that somatostatin signalling regulates energy metabolism and fecundity through anti-proliferative and modulatory actions on primordial germ cells, pancreatic insulin and glucagon cells and the hypothalamus. The ancient origin of the somatostatin system suggests it could act as a switch linking metabolism and reproduction across vertebrates. The results raise the possibility of applications in human and animal fertility.

The silkworm is an economically important insect known for its uniqueness in silk production. Oviposition is an important aspect of insect seed production which needs in-depth study. The aim of this study was to determine the effect of the mating period on the fecundity, egg fertility and performance of bivoltine silkworm. Adult males and females were allowed to mate for 1, 2, 3, 4, 5, and 6 hours respectively. The eggs laid by the mother moth were acid treated, incubated and hatched larvae were reared following standard protocol. The treatments were replicated 5 times and laid out in a Completely Randomized Design. Data were collected on female fecundity, egg fertility, larval and pupal weights, larval survival and cocoon parameters. Data were subjected to analysis of variance and means were separate using DMRT (P

Western flower thrips, Frankliniella occidentalis (WFT), is one of the most destructive insect pests of vegetables and ornamental crops globally. Ultraviolet-C (UV-C) exposure has been shown to reduce populations of arthropod pests, including whiteflies and two-spotted spider mites, but has not been fully assessed for WFT. The goal of this study was to determine if UV-C radiance could be a viable strategy for inclusion in integrated pest management (IPM) programs for WFT. The objectives were to (1) assess the relationship among UV-C dose (irradiance × duration) and mortality of WFT adults and second instar larvae, (2) determine the effect of UV-C on WFT fecundity and egg hatch, and (3) assess the effect of the WFT lethal dose of UV-C on three WFT-prone ornamental plants. A UV-C dose is measured in Joules, which equals power (watts) × exposure time. A dose-dependent relationship between UV-C exposure and mortality of WFT larvae and adults was observed. At the doses of 0.98 and 0.68 J/cm2 (5 and 4 min exposure, respectively), 50% of the larvae died within 24 and 48 h, respectively. The UV-C dose needed to achieve 50% mortality was higher for adults than larvae, occurring at 5.2 and 4.4 J/cm2 (35 min and 25 min exposure, respectively) within 72 and 120 h, respectively. The number of eggs laid by surviving WFT subjected to UV-C treatment was less than by those that were untreated, and the egg-laying period was significantly shorter among those treated with UV-C. When leaves containing WFT eggs were exposed to UV-C doses known to cause 30–40% mortality in adults, 86–98% fewer eggs hatched compared to untreated controls. Ornamental plants exposed to UV-C doses lethal to eggs, second instars, and adult WFT either showed no damage, or when damage occurred, plants recovered within 14–30 days. Additional studies under controlled greenhouse conditions are needed to elucidate the effectiveness of UV-C radiance against WFT over time and its compatibility with biological control and other IPM practices.

Three new populations of the invasive New Zealand mud snail, Potamopyrgus antipodarum, have been discovered in central Chile, increasing the documented records in the country to 23. Only females were observed in the present study. Significant differences in shell length and fecundity were found among populations. The size of the snails was less than 6 mm, while fecundity varied from 0 to 45 offspring per snail. A significant correlation was found between adult shell length and brood size in one of the three populations discovered. In these localities, Potamopyrgus antipodarum coexists with native and possibly other invasive gastropods. [ABSTRACT FROM AUTHOR]