Sows Fecundity by the Maintenance System Diana Marin; Cornelia Petroman; Ioan Petroman ...
Lucrări științifice zootehnie şi biotehnologii,
09/2023, Letnik:
47, Številka:
1
Journal Article
Odprti dostop
Fecundity registered by the females housed in group boxes, with different capacities, has an average of 85.11 ± 1.48, the best results obtained for females housed in boxes with a capacity of 7 heads, ...87.39 ± 1, 47. The proportion of pregnant female at 28 days after artificial insemination decreases with increasing number of animals housed in boxes, so in the case of the animals kept in boxes of 14 animals, fecundity at 28 days was 84.17 ± 0, 93, and in the case of animals kept in boxes with capacity of 28 animals, the fecundity at 28 days was 83.76 ± 2.05. The difference between fecundity recorded in case of animals maintained in boxes of 7 heads was significant compared to fecundity of animals maintained in boxes with 14 and 28 heads (χ2 test p <0.001).
Lack of tree fecundity data across climatic gradients precludes the analysis of how seed supply contributes to global variation in forest regeneration and biotic interactions responsible for ...biodiversity. A global synthesis of raw seedproduction data shows a 250‐fold increase in seed abundance from cold‐dry to warm‐wet climates, driven primarily by a 100‐fold increase in seed production for a given tree size. The modest (threefold) increase in forest productivity across the same climate gradient cannot explain the magnitudes of these trends. The increase in seeds per tree can arise from adaptive evolution driven by intense species interactions or from the direct effects of a warm, moist climate on tree fecundity. Either way, the massive differences in seed supply ramify through food webs potentially explaining a disproportionate role for species interactions in the wet tropics.
A global synthesis of raw seedproduction data shows a 250‐fold increase in seed abundance from cold‐dry to warm‐wet climates, driven by a 100‐fold increase in seed production for a given tree size. The increase in seeds per tree can arise from adaptive evolution driven by intense species interactions or from the direct effects of a warm, moist climate on tree fecundity.
Many animals provide parental care to offspring. Parental sex‐roles vary extensively across taxa, and such patterns are considered well documented. However, information on amphibians is lacking ...relative to other vertebrate groups. We combine natural history observations with functional and historical analyses to examine the evolution of egg care in glassfrogs (Centrolenidae). Parental care was considered rare and predominately provided by males. Our field observations of 40 species revealed that care occurs throughout the family, and the caregiving sex changes across lineages. We discovered that a brief period of maternal care is widespread and occurs in species previously thought to lack care. Using a combination of female‐removal experiments, prey‐choice tests with egg‐eating katydids, and parental disturbance‐tolerance assays, we confirm the adaptive benefits of short‐term maternal care in wild Cochranella granulosa and Teratohyla pulverata. To examine historical transitions between caregiving sexes, we assembled a molecular phylogeny and estimated ancestral care states using our data and the literature. We assessed patterns indicative of sex‐specific constraints by testing whether transitions between the sexes are associated with changes in care levels. Our analyses support that male‐only care evolved 2–3 times from female‐only care, and this change is associated with substantial increases in care levels – a pattern supporting the hypothesis that male‐only care evolved via constraints on maternal expenditure. Many groups of amphibians remain poorly studied, with emerging evidence indicating that care patterns are more diverse than currently appreciated. Natural history remains fundamental to uncovering this diversity and generating testable hypotheses of sex‐role evolution.
Editor's Choice: January 2024 Beukeboom, Leo W.
Entomologia experimentalis et applicata,
January 2024, 2024-01-00, 20240101, Letnik:
172, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Larval nutritional effects on male and female survival and fecundity in Anastrepha ludens – M. Aceituno‐Medina, E. Hernández, O. Rincón‐Betancurt, L. V. García‐Fajardo & E. Diego‐García ...(https://doi.org/10.1111/eea.13383).
The effects of microplastics pollution on the marine ecosystem have aroused attention. Copepod grazing stimulates dimethylsulfide (DMS) release from dimethylsulfoniopropionate (DMSP) in ...phytoplankton, but the effect of microplastics exposure on DMS and DMSP production during copepod feeding has not yet been revealed. Here, we investigated the effects of polyethylene (PE) and polyamide-nylon 6 (PA 6) microplastics on ecotoxicity and DMS/DMSP production in the copepod Tigriopus japonicus. The microplastics had detrimental effects on feeding, egestion, reproduction, survival, and DMS and DMSP production in T. japonicus and presented significant dose-response relationships. The 24 h-EC50 for ingestion rates (IRs) of female T. japonicus exposed to PE and PA 6 were 57.6 and 58.9 mg L−1, respectively. In comparison, the body size of the copepods was not significantly affected by the microplastics during one generation of culture. Ingesting fluorescently labeled microplastics confirmed that microplastics were ingested by T. japonicus and adhered to the organs of the body surface. T. japonicus grazing promoted DMS release originating from degradation of DMSP in algal cells. Grazing-activated DMS production decreased because of reduced IR in the presence of microplastics. These results provide new insight into the biogeochemical cycle of sulfur during feeding in copepods exposed to microplastics.
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•Microplastics had toxic effect on feeding, fecundity, and survival in T. japonicus.•Body size was not significantly impacted by microplastics in one generation time.•Microplastics decreased dimethylsulfide release because of declined ingestion rate.
Adverse effects on feeding, fecundity, survival, and DMS and DMSP production were revealed when T. japonicus were exposed to PE and PA 6 microplastics.
Body size determines total reproductive-energy output. Most theories assume reproductive output is a fixed proportion of size, with respect to mass, but formal macroecological tests are lacking. ...Management based on that assumption risks underestimating the contribution of larger mothers to replenishment, hindering sustainable harvesting. We test this assumption in marine fishes with a phylogenetically controlled meta-analysis of the intraspecific mass scaling of reproductive-energy output. We show that larger mothers reproduce disproportionately more than smaller mothers in not only fecundity but also total reproductive energy. Our results reset much of the theory on how reproduction scales with size and suggest that larger mothers contribute disproportionately to population replenishment. Global change and overharvesting cause fish sizes to decline; our results provide quantitative estimates of how these declines affect fisheries and ecosystem-level productivity.
Rensch's rule suggests that sexual size dimorphism (SSD) increases with species size when males are the larger sex, whereas it decreases when females are the larger sex. However, the process ...responsible for this pattern remains obscure. SSD can result from sexual selection, such as intrasexual competition for access to mates, or from natural selection, due to resource partitioning or fecundity selection. We studied SSD in Caribbean Eleutherodactylus frogs using phylogenetic comparative methods to investigate the influence of microhabitat, fecundity, and parental care. Our results show that in Caribbean Eleutherodactylus females tend to be larger and, contrary to Rensch's rule, dimorphism increases with species size. SSD was not related to microhabitat use. However, SSD was positively correlated with fecundity, mediated by a greater increase in female size. SSD was also influenced by parental care, suggesting that male care promotes larger male size and reduces the female bias in SSD. As suggested for other anurans, female‐biased SSD in Caribbean Eleutherodactylus results from fecundity selection, although the magnitude is countered by increased male size in species with paternal care. Our results highlight the importance of considering various selective forces that may act in concert to influence the evolution of SSD.
Aim
Body size explains most of the variation in fitness within animal populations and is therefore under constant selection from ecological and reproductive pressures, which often promote its ...evolution in sex‐specific directions, leading to sexual size dimorphism (SSD). Several hypotheses have been proposed to explain the vast diversity of SSD across species. These hypotheses emphasize: (a) the mate competition benefits to larger male size (sexual selection); (b) the benefits of larger female size for fecundity (fecundity selection); (c) the simultaneous benefits of niche divergence for males and females to reduce intersexual competition for ecological resources (natural selection); and (d) the underlying impact of geographical variation in climatic pressures expected to shape large‐scale patterns of SSD in synergy with the above selection pressures (e.g., intensification of fecundity selection as breeding seasons shorten). Based on a new, global‐scale amphibian dataset, we address the shortage of large‐scale, integrative tests of these four hypotheses.
Location
Global.
Time period
Extant.
Major taxa studied
Class Amphibia.
Methods
Using a > 3,500 species dataset spanning body size, ecological, life‐history, geographical and climatic data, we performed phylogenetic linear models to address the sexual, fecundity, ecological and climatic hypotheses of SSD.
Results
Evolution of SSD is discordant between anurans and salamanders. Anuran SSD is shaped by climate (male‐biased SSD increases with temperature seasonality) and by nesting site. In salamanders, SSD converges across species that occupy the same types of microhabitats (“ecodimorphs”), whereas reproductive or climatic pressures have no effects on their SSD. These contrasts are associated with latitudinal gradients of SSD in anurans, but not in salamanders.
Main conclusions
Amphibian SSD is driven by ecological and climatic pressures, whereas no roles for sexual or fecundity selection were detected. We show that macroevolutionary processes determined by different forms of selection lead to latitudinal patterns of trait diversity, and the lack of them.
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