Two species of semelparity Nypa palm worms can only reproduce once during their lifetime lives sympatrically. This reproductive is a unique strategy for allocating energy and fecundity to maximize ...fertility and larval survival. Information about energy allocation and fecundity of semelparity Nypa palm worms is not yet available. This study aimed to obtain data on the strategy of two species of sympatric Nypa palm worms related to total energy allocation, fecundity, and larval survival. Energy allocation determining by the proportion between reproductive energy and somatic energy. Fecundity was calculated based on the total number of oocytes obtained from the same individual samples used for energy measurement. Larvae survival was counting the trochophore and 3-setigers larvae resulting from fertilization. Energy allocation, fecundity, and survival were analyzed descriptively. The results showed that both sympatric species allocated energy for reproduction. The fecundity of Namalycastis rhodochorde was higher than that of Namalycastis abiuma, but had lower larval survival than N. abiuma. Fecundity in N. rhodochorde is a strategy to compensate for the low survival rate. Meanwhile, N. abiuma had lower fecundity but had high larval survival. Fecundity and larval survival between the two sympatric Nypa palm worm species differed, but both allocated the same energy. Different larval survival yet similar energy allocation is their strategy to survive in the same environmental conditions. Dua spesies cacing nipah semelparitas yang hanya dapat melakukan reproduksi sekali selama hidupnya ditemukan hidup secara simpatrik. Kemampuan adaptasi ini mengindikasikan adanya strategi yang khas dalam mengalokasikan energi dan fekunditasnya sehingga dapat memaksimalkan fertilitas dan sintasan larva, namun informasi tersebut masih belum tersedia. Tujuan penelitian ini untuk mendapatkan data strategi dua spesies cacing nipah simpatrik terkait dengan alokasi energi total, fekunditas, dan sintasan larva. Alokasi energi dideterminasi dengan menghitung proporsi antara energi reproduksi dan energi somatis. Fekunditas dihitung berdasarkan jumlah total oosit yang didapatkan dari sampel individu yang sama dengan yang digunakan untuk pengukuran energi. Penghitungan sintasan dilakukan dengan menghitung jumlah larva trokofor dan larva 3-setiger hasil fertilisasi. Data alokasi energi, fekunditas, dan sintasan dianalisis secara deskriptif. Hasil penelitian menunjukkan kedua spesies simpatrik mengalokasi energi untuk reproduksi. Fekunditas Namalycastis rhodochorde lebih tinggi dibandingkan Namalycastis abiuma, namun memiliki sintasan larva yang lebih rendah dari N. abiuma. Fekunditas pada N. rhodochorde merupakan startegi untuk mengimbangi rendahnya sintasan. Sementara itu, N. abiuma memiliki fekunditas yang lebih rendah namun memiliki sintasan larva yang tinggi. Fekunditas dan sintasan larva antara kedua spesies cacing nipah simpatrik ditemukan berbeda namun keduanya mengalokasi energi yang sama. Perbedaan fekunditas dan sintasan serta persamaan alokasi energi merupakan strategi spesies simpatrik untuk dapat bertahan hidup pada kondisi lingkungan yang sama.
Abstract
Immune responses are energetically costly to produce and often trade off with investment in reproduction and offspring provisioning. We predicted that hosts can interpret the magnitude of ...the infection threat from cues like initial bacterial load to adjust reproductive investment into offspring quantity and quality.
To test this prediction, we exposed female flour beetles (
Tribolium castaneum
) to naïve or sterile media controls or one of three increasing doses of heat‐killed
Bacillus thuringiensis
(Bt). To estimate offspring quantity, we measured the number of eggs and hatched larvae from each maternal treatment group. To estimate offspring quality, we measured egg protein content, development to pupation, pupal weight and offspring survival against Bt infection.
Compared to naïve controls, low and intermediate bacterial doses resulted in lower female fecundity, suggesting a shift to a somatic maintenance strategy. Meanwhile, in the highest‐dose group, fecundity was negatively correlated with egg protein content. This may reflect a trade‐off between offspring quality and quantity that could mask terminal investment based on metrics of quantity alone.
Our results underscore the need to account for the magnitude of environmental cues when quantifying plasticity and trade‐offs among life history traits, and provide new insight into the transgenerational effects of immune responses.
The thermal ecology of flowers van der Kooi, Casper J; Kevan, Peter G; Koski, Matthew H
Annals of botany,
10/2019, Letnik:
124, Številka:
3
Journal Article
Recenzirano
Odprti dostop
Obtaining an optimal flower temperature can be crucial for plant reproduction because temperature mediates flower growth and development, pollen and ovule viability, and influences pollinator ...visitation. The thermal ecology of flowers is an exciting, yet understudied field of plant biology.
This review focuses on several attributes that modify exogenous heat absorption and retention in flowers. We discuss how flower shape, orientation, heliotropic movements, pubescence, coloration, opening-closing movements and endogenous heating contribute to the thermal balance of flowers. Whenever the data are available, we provide quantitative estimates of how these floral attributes contribute to heating of the flower, and ultimately plant fitness.
Future research should establish form-function relationships between floral phenotypes and temperature, determine the fitness effects of the floral microclimate, and identify broad ecological correlates with heat capture mechanisms.
Social and mating behavior are fundamental fitness determinants in fish. Although fish are increasingly exposed to pharmaceutical compounds that may alter expression of such behavior, potential ...effects are understudied. Here, we examine the impact of lifelong exposure to two concentrations (0.7 and 5.3 μg/L) of the antidepressant fluoxetine on fecundity and social behavior (i.e. sociability and male-male aggression) in the turquoise killifish, Nothobranchius furzeri. When exposed to the highest concentration of fluoxetine (5.3 μg/L), fish were smaller at maturation but they more frequently engaged in mating. In addition, in both fluoxetine treatments females roughly doubled their overall fecundity while egg fertilization rates were the same for exposed and unexposed fish. Although aggression of male fish was not impacted by fluoxetine exposure, exposed male fish (5.3 μg/L) spent more time in the proximity of a group of conspecifics, which implies an increased sociability in these individuals. Overall, the results of this study indicate that exposure to fluoxetine may result in disrupted male sociability, increased mating frequency and an increased reproductive output in fish populations.
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•We studied how fluoxetine exposure affects social and mating behaviour in killifish.•Fluoxetine exposure stimulates mating and sociability.•Fluoxetine exposure increases fecundity but leads to a body size reduction.•Fluoxetine may disrupt social dynamics and mating behaviour in fish populations.
Main finding of the work: Fluoxetine exposure disrupts social behavior and increases reproductive output in the short-lived fish model Nothobranchius furzeri.
To investigate the long-term effects of in utero taxane exposure on exposed daughters’ ovarian reserve and reproductive potential.
Pregnant dams were treated with a single, human-relevant ...animal-equivalent dose of saline, docetaxel, or paclitaxel at embryonic day 16.5. In utero-exposed daughters were aged to multiple postnatal time points for ovarian and endocrine analysis or were bred to assess fertility and fecundity. Granddaughters of treated dams were assessed also for ovarian follicle composition and atresia.
Laboratory study.
C57BL/6 mice.
In utero exposure to saline, docetaxel, or paclitaxel.
Ovarian follicle composition, rates of follicle atresia, and rates of multioocyte follicles were analyzed in all exposure groups. Serum hormone levels and oocyte retrieval outcomes following ovarian hyperstimulation were also assessed. Finally, animals from all exposure groups were bred with the number of litters, pups per litter, live births, interlitter time interval, and age at the last litter analyzed.
We found that docetaxel and paclitaxel exposure in utero results in ovarian toxicity later in life, significantly affecting folliculogenesis as well as increasing the rate of follicular abnormalities, including follicle atresia and multioocyte follicles. Furthermore, viability staining indicates that the ovaries of daughters exposed to taxanes in utero demonstrate a significantly higher number of terminal deoxynucleotidyl transferase dUTP nick end labeling-positive follicles. Hormone measurements also revealed that serum follicle-stimulating hormone concentration was significantly altered in taxane-exposed daughters, with the ratio of luteinizing hormone to follicle-stimulating hormone significantly elevated, specifically after paclitaxel exposure, coincident with the inability of these animals to properly respond to ovarian stimulation. Breeding studies over the course of a year also suggest that these taxane-exposed mice are fertile, although the duration of their fertility is shortened and they produce significantly fewer litters. Finally, ovarian effects are apparent in granddaughters of mice treated with docetaxel, suggesting persistent and multigenerational effects of taxane exposure.
Our studies demonstrate that in utero exposure to taxane-based therapy during late gestation has a significant effect on the long-term reproductive health of exposed daughters (as well as their daughters) and will be instrumental in helping clinicians better understand which chemotherapies for maternal malignancy are least detrimental to a developing fetus.
Sperm is a zootechnical production that is harvested, controlled, processed and used, within a well-defined technological stream.Biotechnological intensification of breeding to increase birth and ...prolificity in zootechnics requires complex control of spermatic production on scientific bases in accordance with current legislation and compliance with national and international standards.In this regard, complex control of sperm production, regardless of its origin, is required by performing ordinary and special spermograms. In the modern technological flow of artificial cattle insemination, processing by dilution is an essential step with obvious zooeconomic implications, because it greatly increases the number of usable doses obtained from an ejaculate, increases the possibility of insemination a much bigger number by larger females, directly contributing to increased male selection pressure.
Oogenesis in fishes follows a universal plan; yet, due to differences in the synchrony and rate of egg development, spawning frequency varies from daily to once in a lifetime. Some species spawn and ...feed in separate areas, during different seasons, by storing energy and drawing on it later for reproduction (i.e. capital breeding). Other species spawn using energy acquired locally, throughout a prolonged spawning season, allocating energy directly to reproduction (i.e. income breeding). Capital breeders tend to ovulate all at once and are more likely to be distributed at boreal latitudes. Income breeding allows small fish to overcome allometric constraints on egg production. Income breeders can recover more quickly when good‐feeding conditions are re‐established, which is a benefit to adults regarding bet‐hedging spawning strategies. Many species exhibit mixed capital‐ and income‐breeding patterns. An individual's position along this capital–income continuum may shift with ontogeny or in relation to environmental conditions, so breeding patterns are a conditional reproductive strategy. Poor‐feeding environments can lead to delayed maturation, skipped spawning, fewer spawning events per season or fewer eggs produced per event. In a few cases, variations in feeding environments appear to affect recruitment variability. These flexible processes of energy acquisition and allocation allow females to prioritize their own condition over their propagules' condition at any given spawning opportunity, thereby investing energy cautiously to maximize lifetime reproductive value. These findings have implications for temporal and spatial sampling designs, for measurement and interpretation of fecundity, and for interpreting fishery and ecosystem assessments.
Rensch's rule relates to a pattern whereby sexual size dimorphism is more female‐biased in small‐sized species and more male‐biased in large‐sized ones. We collected literature and museum data on the ...body size of males and females belonging to 4032 lizard species, as well as data on their reproductive modes and clutch sizes. We used phylogenetic comparative analyses, and general linear mixed models, to test Rensch's rule and examined how reproductive mode and clutch size affect sexual size dimorphism. Sexual size dimorphism was independent of clutch size in lizard species with variable clutch sizes and in oviparous lizards. Large litters were associated with female‐biased sexual dimorphism in viviparous and in scincomorph lizards. Inference regarding Rensch's rule depended on the analytical method used to identify it. The widely used, but less conservative, reduced major axis regression usually support Rensch's rule while ordinary least squares regressions mostly show isometric relationships. The rule tended to apply more to oviparous than to viviparous lizards. We infer that Rensch's rule is, at best, a weak pattern in lizards. This is especially true in viviparous lineages where females reproduce infrequently and therefore evolve large sizes to maximise fecundity, resulting in female‐biased dimorphism.
We studied sexual size dimorphism (SSD) of lizards globally (over 4000 species) and found that male lizards were larger than female lizards overall. The tendency to follow Rensch's rule, however, mainly depended on the line fitting method used. Neither lizard SSD, nor the tendency to adhere to Rensch's rule, seemed to vary with fecundity selection as manifested in clutch size. But reproductive mode influences SSD and adherence to Rensch's rule in lizards.
Per- and polyfluorinated alkyl substances (PFASs) are synthetic organofluorine compounds with unique stability accompanied with hydrophobic and lipophobic properties. Perfluorooctane sulfonate (PFOS) ...and Perfluorooctanoic acid (PFOA) are of high concern due to their wide application in consumer and industrial products, extreme persistence, abundant occurrence in the environment and their toxic effect to humans and animals. However, knowledge on the molecular mechanisms of toxicity and the effects on reproduction output remain scarce. In this study, we analyzed the effects of PFOS and PFOA on Daphnia magna. Acute toxicity, development, reproduction, lipid metabolism (lipid-accumulation) and lifespan was investigated, as well as the expression of genes related to these endpoints. Exposure of PFOS and PFOA at 1, 10 and 25 μM did not cause acute lethality. Hatching was reduced following exposure to both compounds, and lifespan was decreased following exposure to 25 μM PFOS. Body length of Daphnia magna was reduced significantly by 25 μM PFOS following 7 days exposure. Lipid staining revealed that all PFAS exposures increased lipid accumulation. qRT-PCR analysis of genes involved in lipid metabolism suggests that the increase in lipid content could be due to inhibition of genes involved on absorption and catabolism of fatty acids. Exposure to both PFOA and PFOS reduced the fecundity significantly. Downregulation of genes involved in development and reproductive process, including vtg2, vasa, EcRA, EcRB, usp, jhe, HR3, ftz-F1, E74 and E75 were observed. The alterations in developmental and reproductive genes as well as the disturbed lipid metabolism provides mechanistic insight into the possible causes for decreased fecundity and lifespan observed following exposure to both PFOS and PFOA.
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•Per- and polyfluorinated alkyl substances altered lipid metabolism in Daphnia magna.•Daphnia magna reproduction is impaired by both PFOS and PFOA.•The longevity of Daphnia magna is reduced by PFOS but not PFOA•Daphnia magna is a good animal model to investigate pollutants mechanism of action.
Fishes are characterized by a great diversity of reproductive strategies that often make fecundity evaluation difficult. Unlike marine fishes, a single consensual concept of terminology and ...definitions is lacking for freshwater fish fecundity. Several approaches are known from scientific literature for evaluating fecundity in batch spawning fishes of indeterminate fecundity and asynchronous oocyte maturation. These methodological differences impose a bias on the outputs of comparative studies of fecundity. For both theoretical and practical reasons, accurate fecundity data are required to inform the decision-making process in terms of environmental policy and the related applications for the control of non-native species and the conservation management of native species and ecosystems. The main aim of the present study was to review briefly the existing fecundity-evaluation methods, to test among-method compatibility, and to develop a new approach that aims to make fecundity evaluation more systematic and transparent. A simulated 'test' dataset demonstrated considerable variability in the results obtained from the various existing approaches. The literature review and our analyses revealed a need for standardization. Thus, a new approach is proposed here that is based on multiple sampling throughout the reproductive cycle; provides greater overall detail of the species' reproductive traits and permits inter-population comparisons.
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