Mature Females Research Articles

Investigation of the Influence of Hypercapnia on the Physiology of Ovigerous West Coast Rock Lobsters, Jasus lalandii, and Their Embryonic Development

The West Coast rock lobster, Jasus lalandii, is a key ecological species and provides an important fishery resource in South Africa and Namibia. It is found along the west coast of southern Africa in the dynamic Benguela Current upwelling system. The low seawater pH of this system is expected to decline further due to ocean acidification and increase in upwelling in terms of frequency and severity. The lobster has therefore to respond to frequent and rapid changes in pH and other environmental impacts that are predicted to become more adverse in future. Although responses to such conditions are known for mature male and juvenile lobsters, there is a lack of information on mature females and later embryonic development. We addressed this by analysing the sensitivity of ovigerous (“berried”) female WCRLs and their eggs/embryos to hypercapnia (high pCO2, low pH) and formulated the following research questions: (1) Can berried female WCRLs respond swiftly to large changes in pH? (2) What physiological mechanisms facilitate a potential response to a rapidly declining pH, i.e., acute hypercapnia? (3) Does a potential response persist during prolonged hypercapnia? (4) Are eggs/embryos impacted by hypercapnia? To investigate this, we exposed berried WCRLs to acute (pH 7.5) and chronic (up to 60 days at pH 7.5 and 7.8) hypercapnia. We applied extracellular acid–base analysis, microscopic examination of egg growth and development, and SEM of female exoskeleton structure and egg membranes. The results revealed that berried females efficiently respond to acute and chronic hypercapnia by means of increasing bicarbonate concentrations in the haemolymph. Moreover, embryo growth and development are not impacted by chronic hypercapnia, but growth shows geographical area-specific differences. We conclude that females and embryos of J. lalandii are as resilient to hypercapnia as previously shown for males and juveniles.

INSIGHTS INTO THE REPRODUCTIVE BIOLOGY AND AGE AT MATURITY OF CLIMBING PERCH, Anabas testudineus (BLOCH, 1792) IN MALAYSIA

Understanding the reproductive biology and age at maturity of climbing perch (Anabas testudineus) is essential for effective aquaculture management and broodstock development. This study examined the species’ reproductive traits under laboratory conditions, focusing on fecundity, Gonadosomatic Index (GSI), Hepatosomatic Index (HSI), and age at maturity. Fecundity was assessed in 30 mature females (total length: 11.0 to 15.0 cm; weight: 32.72 to 68.92 g), which exhibited a fecundity range of 23,316 to 71,862 eggs, with a mean of 49,498 eggs. Positive linear relationships were observed between fecundity and parameters such as total length, body weight, and gonad weight. GSI values ranged from 14.26% to 28.32% and HSI ranged from 0.80% to 1.58%. Gonadal development and age at maturity were studied in juveniles with histological analysis revealing that males reached maturity at 4.5 months (12.66 ± 1.73 cm, 34.54 ± 10.56 g, n = 30), while females matured at 5 months (12.4 ± 0.96 cm, 48.06 ± 14.59 g, n = 30). The gonads of both sexes progressed through distinct stages of development with maturity being reached during the latter stages. These findings indicate that climbing perch achieve sexual maturity within five months under controlled conditions and these insights provide critical information in optimising broodstockmanagement and seed production strategies. The study offers significant implications for aquaculture practices aimed at enhancing sustainability and productivity.

Divergence in genetic (co)variances and the alignment of gmax with phenotypic divergence.

To better understand the sources of biological diversity in nature, we need information on the mechanisms underlying population divergence. Biological systems with patterns of naturally occurring adaptive variation among populations can provide insight into the genetic architecture of diverging traits and the influence of genetic constraints on responses to selection. Using a system of reproductive character displacement in the North American mushroom-feeding fly Drosophila subquinaria, we assessed patterns of genetic (co)variance among a suite of chemical signaling traits and divergence in this pattern among populations. D. subquinaria exhibits stronger reproductive isolation against the closely related Drosophila recens in sympatry, where both female mating preferences and male chemical signaling traits have diverged from the ancestral allopatric populations. We collected three wild populations from each region and, in the lab, characterized the phenotypic divergence in these traits, as well as the additive genetic (co)variance structure (G-matrix), via replicate breeding designs. We found divergence between allopatric and sympatric D. subquinaria in the shape and size of the G-matrix, and that the leading axis of genetic variance (gmax) had changed in sympatry to come into alignment with the primary axis of phenotypic divergence between the sympatric and allopatric regions.

Talent identification and development in judo: A systematic review

This review synthesizes the existing literature about talent identification and development in judo and provides evidence-based suggestions to help researchers and practitioners in this area. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used to identify relevant studies (n = 45). The mean quality of the evidence was 94.0%. Most of the studies were published between the years 2014 and 2021 with cross-sectional designs and group comparisons or performance prediction. Studies used batteries of tests focused on expert or advanced samples and measured individual constraints. Few studies examined female samples, psychological skills or biological maturation. Only 20% of the studies used multivariate analyses. On closer examination, there was a high degree of variability in the indicators that were found to discriminate between skilled and less-skilled judo athletes, predict performance and/or predict career pathway. Research in talent identification and development in judo has generally focused on individual constraints related to anthropometric and physiological characteristics, and technical skills in cross-sectional designs. Very little is known about what talent indicators discriminate high skilled judo athletes or predict actual performance or future success. Future research should adopt multidimensional and longitudinal approaches that integrate existing findings about the maturational, psychological and environmental aspects of judo for tracking the most talented judo athletes, especially in female samples.

Understanding the impact of host plant factors on the oviposition behaviour of the cabbage stem flea beetle (Psylliodes chrysocephala)

AbstractFor many phytophagous insects, oviposition plays a key role in the selection of an appropriate host. A more comprehensive understanding of the factors influencing this behaviour in pest insects provides a basis for the development of new management strategies. Herein, the determinants of oviposition were assessed in the cabbage stem flea beetle, Psylliodes chrysocephala (Coleoptera: Chrysomelidae), an insect specialized on the Brassicaceae family and a major pest of oilseed rape crops in Europe. To this end, a controlled condition experiment was conducted, in which a range of host plants exhibiting varying degrees of acceptability for feeding were presented to mature females. A superior host, Brassica rapa pekinensis, an intermediate one, Brassica napus, and a non‐host plant, Iberis amara, were used. An additional treatment involved wrapping the plants in micro‐perforated plastic bags to prevent feeding on aerial parts. The results demonstrated that contact with the host plant, and more particularly feeding, stimulated oviposition, with this effect being more pronounced in B. napus. Indeed, for the same amount of feeding, females laid significantly more eggs when feeding on B. napus than when feeding on B. rapa pekinensis. Additionally, a sequential experiment demonstrated that the intensity of oviposition is subject to rapid adaptive changes, as it is exclusively dependent on the current dietary conditions, with no influence of past dietary regimens. The quantification of macronutrients indicated the potential influence of plant‐digestible carbohydrates on these outcomes. Further investigation is required to determine the impact of the plant nutritional quality and defences on oviposition.

Skeletal Maturity Might Not Be a Factor in Optimizing Outcomes in Total Hip Arthroplasty.

Introduction Total hip arthroplasty (THA) is rarely indicated in the skeletally immature population. In these instances, there is concern for implant survival compared to the traditional older population. There has been a steady rise in the use of THA in the pediatric population due to improvements in surgical techniques. While the outcomes in THA for skeletally immature patients have been described in the literature, there are no population studies looking at this procedure in a skeletally immature individual. Therefore, the purpose of this study was to compare 10-year implant survivability following primary THA in skeletally mature versus skeletally immature patients. Methods Patients who underwent primary THA were identified using a large national database (PearlDiver). THA patients were then divided into presumed skeletally immature male patients (0-16 years), presumed skeletally mature male patients (17-21 years), presumed skeletally immature females (0-14 years), and presumed skeletally mature females (15-21 years). Multivariable analysis was conducted using Cox proportional hazards modeling to determine differences in the risk of revision for periprosthetic joint infection (PJI), mechanical loosening, dislocation/instability, and periprosthetic fracture (PPF). Results In total, 352 male patients (244 skeletally mature and 108 skeletally immature) and 409 female patients (350 skeletally mature and 59 skeletally immature) were identified. Compared to skeletally immature females, skeletally mature females had no higher risk of 10-year revision for all-cause, PJI, mechanical loosening, dislocation/instability, or PPF (P > 0.05 for all). Compared to skeletally immature males, skeletally mature males had no higher risk of 10-year revision for all-cause, PJI, mechanical loosening, dislocation/instability, or PPF (P > 0.05 for all). Conclusion Although THA occurred more commonly in patients above the presumed age of skeletal maturity, the lack of significantly different surgical outcomes suggests that younger age and presumed skeletal immaturity may not put patients at any further risk of implant failure. While further research is needed to understand the impact of age and skeletal maturity on outcomes of THA, these results indicate that the initial age of a THA may not be a factor in optimizing outcomes, and suggests that orthopedic surgeons need not delay surgery based on age or skeletal maturity alone.

Neurosteroid replacement therapy using tiagabine and zuranolone restores cerebellar neurodevelopment and reduces hyperactive behaviour following preterm birth.

Preterm birth exposes the neonate to hypoxic-ischaemic and excitotoxic insults that impair neurodevelopment and are magnified by the premature loss of placentally supplied, inhibitory neurosteroids. The cerebellum is a neuronally dense brain region, which undergoes critical periods of development during late gestation, when preterm births frequently occur. We propose that neurosteroid replacement therapy using tiagabine and zuranolone will protect the cerebellum against preterm-associated insults. Guinea pig dams received c-section surgery preterm (gestational age (GA) 64) or at term (GA70) with preterm pups administered tiagabine (2.5 mg/kg/day), zuranolone (1 mg/kg/day) or vehicle (15% β-cyclodextrin) until term equivalent age (GA70). Behavioural testing was performed at corrected postnatal day 8 (PND8) and PND41 with tissue collection occurring at PND42. Neurodevelopmental markers (MBP, OLIG2 and NeuN) were assessed within the cerebellum by immunohistochemistry, whilst GABAergic and glutamatergic pathway expression was quantified using high throughput RT-PCR. Zuranolone and, to a lesser extent, tiagabine were able to protect against hyperactive behaviour at PND8 in males, whilst in females, a less marked hyperactive phenotype was present with neither treatment impacting behaviour further. Both treatments improved MBP staining, whilst tiagabine was found to restore oligodendrocyte maturation in females only. GABAergic and glutamatergic pathway expression was found to be restored by both treatments in females. Overall, this study demonstrates the neuroprotective attributes of neurosteroid replacement therapy using tiagabine and zuranolone, thereby demonstrating their potential to mitigate long-term neurodevelopmental impairments. Furthermore, the sexually dimorphic effects observed suggest future investigations may show increased benefit by using sex-specific treatment regimes.

More eggs are not more sires: long-term monogamy reduces fertility in a predatory ladybird.

Multiple mating is a behaviour observed across various polyandrous insect species. It is suggested that, in ladybirds, this strategy of multiple copulations is used to enhance fecundity and fertility through sperm replenishment. Studies on sperm depletion need to correlate fertility with the presence of spermatozoa in the spermatheca. This study investigates the role of sperm replenishment in the ladybird Cryptolaemus montrouzieri. We hypothesised that females of this species exhibit fecundity and fertility rates proportional to the number of sperm replenishment opportunities (constant, periodic or absent). We observed oviposition behaviour and hatching rates over 30 days, and simultaneously tested for sperm depletion in females that copulated once. We dissected the spermathecae at four post-copulation moments to count spermatozoa under a microscope. Our results indicate that a single copulation suffices to maintain fertility for at least 30 days. Females with constant replenishment opportunities exhibited higher fecundity but lower fertility and increased mortality, suggesting a reproductive cost associated with frequent mating. Females with no replenishment during the experiment, exhibited the highest hatchability rate and lowest oviposition. Periodic copulation resulted in optimal female mating rate, with average fertility and fecundity. A plausible hypothesis would be that paired females choose to fertilise fewer eggs from a single male but are unable to control the effects of the oviposition stimulus induced by the male's presence. These findings have implications for the management and rearing of C. montrouzieri in biological control programmes, optimizing mating strategies for mass production.

Lethal Male Combat of Anastatus japonicus (Hymenoptera: Eupelmidae), an Egg Parasitoid of Lepidopterous and Hemipterous Pests.

Aggressive interactions between males are common when victors gain increased mating success but can result in severe injury or death for the defeated. Anastatus japonicus (Hymenoptera: Eupelmidae) is a solitary egg parasitoid of hemipteran and lepidopteran species. Here, we investigated lethal interactions between A. japonicus males and analyzed aggression behavior scaled with the male condition, number of competitors, number of presented females, and female mating status. The intensity of A. japonicus male aggressiveness increased with the number of competitors and the number of presented females but was not affected by male relatedness. The intensity and frequency of A. japonicus male aggressive interactions were greater when males competed for virgin females compared to mated females. Larger A. japonicus males won more contests than smaller males and honey-fed males defeated starved ones, where defeated males suffered the loss of appendages and/or died. Fighting appeared to be the norm in all-male groupings, regardless of the presence of females. A number of biological and ecological factors are deducted that likely contribute to the evolution of male aggressive behavior in A. japonicus.

Stock Dynamics of Female Red King Crab in a Small Bay of the Barents Sea in Relation to Environmental Factors.

Stock-recruitment relationships depend on the total abundance of females, their fecundity, and patterns of their maturation. However, the effects of climatic conditions on the abundance, biomass, and mean weight of female red king crabs, Paralithodes camtschaticus, from the introduced population (Barents Sea) have not yet been studied. For this reason, we analyzed long-term fluctuations in stock indices and the average weight of an individual crab in a small bay of the Barents Sea and related these parameters to the dynamics of temperature conditions (temperature in January-December, mean yearly temperature, and temperature anomaly) in the sea. The average weight of a crab at age 6-9 had strong negative correlations with water temperature at lags 8 and 9, indicating faster female maturation in warm periods. Positive relationships were registered between temperature and stock indices for 15-19-year-old females at lag 4 and for 10-14-year-old females at lag 10, supporting the idea of higher survival rates of juveniles and their rapid development being a response to a pool of warm waters. Both redundancy and correlation analyses revealed seawater temperatures in June-August being the most important predictors of female abundance and biomass, indicating that favorable temperature conditions in the first 3 months of crab benthic life result in high survivorship rates for red king crabs.

Small‐Scale Recovery of a Native White‐Spotted Charr Population by Suppression of Non‐Native Brown Trout

ABSTRACTIf eradication is not feasible, suppressing a population size of non‐native species by removal is an alternative option for the conservation of native species that are impacted by non‐native species invasions. This study reports on the suppression of non‐native brown trout for the conservation of native white‐spotted charr in an upstream of Monbetsu Stream, Hokkaido, northern Japan. Brown trout removals were conducted from 2014 to 2023 by electrofishing. The population size of brown trout was dramatically reduced during the first three years of removals, and the ratio of white‐spotted charr to brown trout abundance gradually increased. However, the population size of white‐spotted charr did not fully recover, which can be explained by the openness of the system and likely also by the influence of interfering factors observed during the study, such as changes in stream morphology due to flooding and suspected illegal fish stocking. The abundance of young‐of‐the‐year brown trout also tended to be reduced when numerous mature females had been removed in previous years. This study suggests that suppressing non‐native fish species, even on a limited scale, can contribute to the conservation of native species. However, when preventing migration from downstream into the target stream reach is unfeasible, ongoing suppression of non‐native species becomes essential to ensure the conservation of native species in the area.

Decoding Vitellogenin Subtype Responses: A Molecular Approach to Biomarkers of Endocrine Disruption in Scatophagus argus

Vitellogenins (Vtgs) are key yolk precursor proteins in fish, serving as critical indicators of gonadal maturation in females and reliable biomarkers for detecting xeno-oestrogenic pollution, particularly through their expression in juveniles or males. The vtg gene family comprises multiple subtypes that are species-specific, necessitating precise characterisation and quantification for effective use as biomarkers in studies on estrogenic endocrine-disrupting chemicals (EEDCs). In this study, we successfully cloned and characterised the full-length cDNAs of three vtg subtypes (vtgAa, vtgAb, and vtgC) from Scatophagus argus. Differential expression analysis revealed that vtgAb exhibited the highest responsiveness to 17α-ethynylestradiol (EE2) exposure, with a 3-fold increase in vivo at 10.0 μg/g EE2 and a 30-fold increase in vitro at 10−7 mol/L EE2. The expression patterns were dose- and time-dependent, with peak expression observed 72 h post-exposure. While in vivo assays indicated moderate upregulation, in vitro experiments demonstrated significantly higher expression, attributed to direct hepatocyte interaction with EE2. These findings confirm vtgAb as the most responsive subtype to oestrogen exposure in S. argus and highlight the species’ tolerance to EE2, as compared to more sensitive species like Danio rerio. This study shows the evolutionary conservation of vtg transcripts across teleost species and reinforces the importance of subtype-specific characterisation to advance their application as biomarkers for EEDCs, with significant implications for environmental monitoring and pollution regulation.

First report of hard shell female mating in the crenate swimming crab, Thalamita crenata Ruppell, 1830 (Crustacea: Decapoda: Portunidae)

The mating behaviour of crustaceans, particularly brachyuran crabs, is commonly associated with the female molting cycle, with soft shell mating prevalent among sexually reproducing species, while hard shell mating is a rarely observed adaptation within the subfamily Thalamitinae. This study marks the initial documentation of hard shell female mating in Thalamita crenata, a portunid crab. The study aims to elucidate the reproductive dynamics of T. crenata by capturing and observing mating behaviours in captivity. Mature T. crenata individuals of both sexes were captured and housed in controlled conditions. Observations were conducted to document hard shell mating behaviours, employing digital video and photography for detailed analysis. After 50 days, a notable instance of hard shell mating was observed, characterized by forceful gripping and flipping manoeuvres by the male, culminating in copulation lasting approximately 8 minutes. This discovery enriches our understanding of T. crenata‘s reproductive ecology, providing insights into unique mating strategies within the subfamily Thalamitinae. This discovery encourages further exploration of captive breeding possibilities and contributes to a holistic comprehension of crustacean mating strategies.

Addressing life history information gaps for Caribbean parrotfishes: queen parrotfish Scarus vetula and stoplight parrotfish Sparisoma viride

Queen parrotfish Scarus vetula and stoplight parrotfish Sparisoma viride are widely distributed throughout the subtropical/tropical regions of the northwestern Atlantic, play important ecological roles in reef ecosystems, and contribute to small-scale commercial landings within several Caribbean management jurisdictions. Prior to this work, no comprehensive life history information existed for either species that combined otolith analysis and gonad histology. Queen parrotfish (n = 390) and stoplight parrotfish (n = 1801) were sampled throughout the U.S. Caribbean from 2013 to 2023. Queen parrotfish range in size from 82 to 402 mm FL and age from 0 to 16 years; stoplight parrotfish ranged from 73 to 433 mm FL and 0 to 20 years. Growth parameter estimates for queen parrotfish were L∞ = 347 mm FL and K = 0.42, when t0 was fixed to −0.06; for stoplight parrotfish, L∞ = 332 mm FL and K = 0.39, with a fixed t0 of −0.06. All female queen parrotfish transitioned to males by a maximum length and age of 322 mm FL and 14 years. In contrast, not all female stoplight parrotfish transitioned to males since the largest and oldest individuals sampled were females. Spawning capable queen parrotfish females were collected from November to August indicating a protracted spawning season of 10 months. Stoplight parrotfish exhibited year-round spawning with >50% of mature females in the spawning capable phase during all months of the year. Based on our overall findings related to life history, queen parrotfish and stoplight parrotfish in the U.S. Caribbean did not appear to exhibit signs of overexploitation which may in part relate to U.S. Caribbean management efforts currently in place that limit the minimum mesh size for traps (which ensures that smaller fish can escape from the traps), a ban on using gillnets to target parrotfish species, and the market driven targeting of “plate-size” fish by commercial spearfishers. The life history information documented in the current study will provide essential information for stock assessments and informed management in the U.S. Caribbean for these two important parrotfish species.

Can Aluminum Affect Social Behavior and Cortisol Plasma Profile in the Neotropical Freshwater Teleost Astyanax lacustris (Teleostei: Characidae)?

Aluminum (Al) can cause endocrine disruption in aquatic animals, but assessments of animal social behavior in neotropical teleost fish species with importance for Brazilian aquaculture have still not been addressed so far, which can further complete this ecotoxicological knowledge. In order to evaluate the social behavior and plasma cortisol concentration of fish exposed to Al, we performed a 1 h acute exposure with Astyanax lacustris couples in three different experimental groups: control in neutral pH (CTL/n group), acid pH (pH/ac group), and aluminum in acid pH (Al/ac group; 2.0 mg L-1). An ethogram of social interactions between males and females and swimming activities were performed. Furthermore, the cortisol plasma concentration was measured by enzyme-linked immunosorbent, and the gonadal maturation stage of the animals was evaluated by histology. Adult and mature females in the CTL/n and pH/ac groups were more aggressive and active than mature males, including several attacks on the male. Moreover, males did not present attack behavior in these groups at any time, but did show submission behavior and constant avoidance of female attacks. In the Al/ac, females did not attack males, couple decreased swimming activity, a repetitive movement toward the aquarium surface, and high mucus production were observed, making the water cloudy. Regarding cortisol plasma concentration, males had higher cortisol plasma concentrations than females in the CTL/n and pH/ac groups, which was not observed in the Al/ac group. Therefore, Al in addition to being described in the literature as an endocrine disruptor, it can be considered as behavioral disrupter in A. lacustris in this important freshwater species cultivated in South America.

Repetitive Overuse Injury Causes Entheseal Damage and Palmar Muscle Fibrosis in Older Rats.

Overuse injury is a frequent diagnosis in occupational medicine and athletics. Using an established model of upper extremity overuse, we sought to characterize changes occurring in the forepaws and forelimbs of mature female rats (14-18 months of age). Thirty-three rats underwent a 4-week shaping period, before performing a high-repetition low-force (HRLF) task for 12 weeks, with the results being compared to 32 mature controls. HRLF animals showed a reduced grip strength versus controls. ELISAs carried out in the HRLF rats, versus controls, showed elevated levels of IL1-α in tendons, IL1-α and TNF-α in distal bones/entheses, and TNF-α, MIP1-α/CCL3, and CINC-2/CXCL-3 in serum, as well as IL-6 in forelimb muscles and tendons, and IL-10 in serum. HRLF rats had elevated collagen deposition in the forepaw intrinsic muscles (i.e., fibrosis), entheseal microdamage, and articular cartilage degradation versus the control rats. CD68/ED1+ osteoclasts and single-nucleated cells were elevated in distal forelimb metaphyses of the HRLF animals, versus controls. Declines in grip strength correlated with muscle fibrosis, entheseal microdamage, articular cartilage damage, distal bone/enthesis IL1-α, and serum IL-6. These data demonstrate inflammatory and persistent degradative changes in the forearm/forepaw tissues of mature female animals exposed to prolonged repetitive tasks, changes with clinical relevance to work-related overuse injuries in mature human females.

Assessing changes in threatened black rockcod Epinephelus daemelii abundance and length over the past 15 years in New South Wales, Australia.

Ideally, protection of a threatened fish will lead to their recovery in abundance, distribution, and size structure within the population, to a point where they are no longer considered threatened. Monitoring abundance and size is crucial to evaluate this, although low numbers associated with being threatened can strongly constrain the methods used. To assess if population recovery is occurring for the black rockcod Epinephelus daemelii, a large subtropical grouper endemic to shallow reefs in the southwest Pacific, surveys were undertaken across northern New South Wales and Lord Howe Island using roving diver timed counts and diver stereo-video measurements to assess relative abundance and length. Surveys in 2023 were compared with initial baseline data captured in 2009-2011 using the same methods. Relative abundance of E. daemelii at long-term monitoring sites has remained relatively constant or declined since 2010 rather than increasing. Comparisons between 84 broadscale sites in 2009-2011 versus 2023 (117 vs. 69 observed E. daemelii) indicate a recent decline in abundance. Although protected from fishing and spearfishing for over 40 years, the relative abundance of E. daemelii does not appear to be increasing over the past 15 years since monitoring commenced. This is a concerning trend that does not indicate recovery, although an increase in the proportion of mature females in the population from 2010 to 2023 is positive. As E. daemelii is slow growing, long lived, late to mature and still susceptible to incidental capture mortality, more active management may be needed to help assist with the slow recovery of this threatened species.

Coypu (Myocastor coypus bonaeriensis) Ovarian Morphology During the Oestrous Cycle.

The coypu (Myocastor coypus bonariensis) is an annual polyestrous hystricomorph rodent with variable-length oestrous cycles, which ovarian histoarchitecture during this period is not fully described. This study analyses variations in ovarian morphology during the oestrous cycle, focusing on follicular development and atresia. Eighteen sexually mature virgin females aged 7-9 months, weighing 4.795 ± 0.3996 kg, were used. Daily colpocytological analyses were performed to establish the cycle duration, followed by euthanasia at different phases-prooestrus, estrus, meteostrus, and on days 5, 10, and 20 of dioestrus. Morphology and superficial appearance of the ovaries, weight, and volume at each stage were recorded, and volume increase over time was analysed. A morphological classification and size ranges every 100 μm for follicular development analysis were used. Relative area analysis determined the proportions of different ovarian components and the absolute and relative frequencies of atretic and/or luteinized structures. Our study revealed differences between prooestrus, meteostrus, and all dioestrus phases, as well as between oestrus and metoestrus, and dioestrus at 10 and 20 days. Ovarian surface exhibited variations across different oestrous cycle stages, and atretic follicles were observed in all analysed stages. These findings provide new data and contribute to the understanding of the reproductive cycle in this species.

Humpback whales (Megaptera novaeangliae) in Hervey Bay, Australia: a stopover for females early in their southern migration

In the Southern Hemisphere, humpback whales (Megaptera novaeangliae) migrate along the extended continental coastlines of Australia, South America, and South Africa. This study reports on photo-identification capture–recapture data from a long-term survey conducted in Hervey Bay, Queensland, where a substantial proportion of the population stop over early in the southern migration. Photo-identification data were collected over 10 weeks per year from 1997 to 2009. The migration through Hervey Bay is dominated and led by females with high fidelity to the site. Mature females, yearlings, and immature whales use the Bay during August, while mature lactating females with calves dominate during September and October. Complex social behaviours occur throughout the season and differ between the early and late cohorts. We argue that the composition of the two cohorts and their distinctively different behaviours indicate that Hervey Bay is not simply a resting site but an area of aggregation that serves important social and biological benefits. A multistate open robust design model was fitted to capture–recapture data to estimate the annual number of whales visiting the Bay, the permanent emigration rate, proportions of the visiting population that do not enter the Bay each year, the number present during each week, and their residency times. The number of annual visitors to the Bay increased approximately linearly from 857 in 1997 to 2175 at the end of sampling in 2009 with two-thirds migrating through during the first half of each season. The population rate of growth may have been slowing by 2009, but there was considerable uncertainty in the trajectory and little basis for projection into the future. While it is desirable to know the current status of the Hervey Bay population and what has occurred since 2009, the cost and effort required make further manual collection and matching of images unlikely. The development of AI algorithmic matching software may enable further research in future.

Morphological characteristics, developmental dynamics, and gene temporal expressions across various development stages of Aphis gossypii sexual female

BackgroundAphis gossypii (Hemiptera: Aphididae) is a worldwide polyphagous phloem-feeding agricultural pest, and it can produce offspring by sexual or asexual reproduction. Compared with dozens of generations by parthenogenesis, sexual reproduction is performed in only one generation within one year, and little is known about the sexual reproduction of A. gossypii. In this study, sexual females of A. gossypii were successfully obtained through a previously established induction platform, and the morphological characteristics, developmental dynamics, and temporal gene expression were examined. Subsequently, signaling pathways potentially involved in regulating the growth, development, and reproduction of sexual females were investigated.ResultsThe morphological observation showed that from the 1st instar nymph to adult, sexual females exhibited a gradually deepened body color, an enlarged body size, longer antennae with a blackened end, and obviously protruding cauda (in adulthood). The anatomy found that the ovaries of sexual females developed rapidly from the 2nd instar nymph, and the embedded oocytes matured in adulthood. In addition, time-course transcriptome analysis revealed that gene expression profiles across the development of sexual females fell into 9 clusters with distinct patterns, in which gene expression levels in clusters 1, 5, and 8 peaked at the 2nd instar nymphal stage with the largest number of up-regulated genes, suggesting that the 2nd instar nymph was an important ovary development period. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis revealed that a large number of genes in the sexual female adult were enriched in the TGF-beta signaling pathway and Forkhead box O (FoxO) signaling pathway, highlighting their important role in sexual female adult development and reproduction.ConclusionThe morphological changes of the sexual female at each developmental stage were revealed for the first time. In addition, time-course transcriptomic analyses suggest genes enriched in the TGF-beta signaling pathway and FoxO signaling pathway probably contribute to regulating the development and oocyte maturation of sexual females. Overall, these findings will facilitate the regulating mechanism research in the growth and development of sexual females by providing candidate genes.