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1.
Understanding the interconnectivity of organisms among different habitats is a key requirement for generating effective management plans in coastal ecosystems, particularly when determining component habitat structures in marine protected areas. To elucidate the patterns of habitat use by fishes among coral, seagrass, and mangrove habitats, and between natural and transplanted mangroves, visual censuses were conducted semiannually at two sites in the Philippines during September and March 2010–2012. In total, 265 species and 15,930 individuals were recorded. Species richness and abundance of fishes were significantly higher in coral reefs (234 species, 12,306 individuals) than in seagrass (38 species, 1,198 individuals) and mangrove (47 species, 2,426 individuals) habitats. Similarity tests revealed a highly significant difference among the three habitats. Fishes exhibited two different strategies for habitat use, inhabiting either a single (85.6% of recorded species) or several habitats (14.4%). Some fish that utilized multiple habitats, such as Lutjanus monostigma and Parupeneus barberinus, showed possible ontogenetic habitat shifts from mangroves and/or seagrass habitats to coral reefs. Moreover, over 20% of commercial fish species used multiple habitats, highlighting the importance of including different habitat types within marine protected areas to achieve efficient and effective resource management. Neither species richness nor abundance of fishes significantly differed between natural and transplanted mangroves. In addition, 14 fish species were recorded in a 20-year-old transplanted mangrove area, and over 90% of these species used multiple habitats, further demonstrating the key role of transplanted mangroves as a reef fish habitat in this region.  相似文献   

2.
The recruitment of juvenile corals and post-settlement mortalityare important processes for coral population dynamics and reefcommunity ecology. I monitored juvenile coral recruitment andsurvival on a severely disturbed reef in Bermuda from 1981 to1989 and on adjacent healthy reefs from 1986 to 1990. Poritesastreoides was the dominant recruiting species at all sites,due to the release of brooded planulae that may settle rapidly.The dominant corals on Bermuda's reef, Diploria spp., were poorrecruiters, perhaps due to the broadcast mode of reproductionof these species. However, Diploria spp. have lower juvenilemortality rates compared to P. astreoides, which may explaintheir abundance on Bermuda's reefs. Brooding corals, primarily agariciids, were the dominant recruitson Atlantic reefs compared to high recruitment rates by spawningacroporids in the Pacific, which may be the result of differentenvironmental conditions and/or evolutionary trends in the twooceans. The latter group also suffered high post-settlementmortality compared to brooding coralsin both the Atlantic andthe Pacific. Massive corals in both oceans had generally lowrecruitment rates, related to their spawning mode of reproduction,and low rates of post-settlement mortality. The dominant roleof long-lived massive corals on the Atlantic and Pacific reefscan be understood in terms of their life-history strategy incomparison to the relatively short-lived Pacific acroporidsand Atlantic agariciids that rely on different strategies tomaintain their populations.  相似文献   

3.
Understanding patterns in species richness and diversity over environmental gradients (such as altitude and depth) is an enduring component of ecology. As most biological communities feature few common and many rare species, quantifying the presence and abundance of rare species is a crucial requirement for analysis of these patterns. Coral reefs present specific challenges for data collection, with limitations on time and site accessibility making efficiency crucial. Many commonly used methods, such as line intercept transects (LIT), are poorly suited to questions requiring the detection of rare events or species. Here, an alternative method for surveying reef-building corals is presented; the point count transect (PCT). The PCT consists of a count of coral colonies at a series of sample stations, located at regular intervals along a transect. In contrast the LIT records the proportion of each species occurring under a transect tape of a given length. The same site was surveyed using PCT and LIT to compare species richness estimates between the methods. The total number of species increased faster per individual sampled and unit of time invested using PCT. Furthermore, 41 of the 44 additional species recorded by the PCT occurred ≤ 3 times, demonstrating the increased capacity of PCT to detect rare species. PCT provides a more accurate estimate of local-scale species richness than the LIT, and is an efficient alternative method for surveying reef corals to address questions associated with alpha-diversity, and rare or incidental events.  相似文献   

4.

Background

Coral reefs face increasing pressures particularly when on the edge of their distributions. The Houtman Abrolhos Islands (Abrolhos) are the southernmost coral reef system in the Indian Ocean, and one of the highest latitude reefs in the world. These reefs have a unique mix of tropical and temperate marine fauna and flora and support 184 species of coral, dominated by Acropora species. A significant La Niña event during 2011 produced anomalous conditions of increased temperature along the whole Western Australian coastline, producing the first-recorded widespread bleaching of corals at the Abrolhos.

Methodology/ Principal Findings

We examined long term trends in the marine climate at the Abrolhos using historical sea surface temperature data (HadISST data set) from 1900–2011. In addition in situ water temperature data for the Abrolhos (from data loggers installed in 2008, across four island groups) were used to determine temperature exposure profiles. Coupled with the results of coral cover surveys conducted annually since 2007; we calculated bleaching thresholds for monitoring sites across the four Abrolhos groups.

Conclusions/ Significance

In situ temperature data revealed maximum daily water temperatures reached 29.54°C in March 2011 which is 4.2°C above mean maximum daily temperatures (2008–2010). The level of bleaching varied across sites with an average of ∼12% of corals bleached. Mortality was high, with a mean ∼50% following the 2011 bleaching event. Prior to 2011, summer temperatures reached a mean (across all monitoring sites) of 25.1°C for 2.5 days. However, in 2011 temperatures reached a mean of 28.1°C for 3.3 days. Longer term trends (1900–2011) showed mean annual sea surface temperatures increase by 0.01°C per annum. Long-term temperature data along with short-term peaks in 2011, outline the potential for corals to be exposed to more frequent bleaching risk with consequences for this high latitude coral reef system at the edge of its distribution.  相似文献   

5.
Cyclone Yasi, one of the most severe tropical storms on record, crossed the central Great Barrier Reef (GBR) in February 2011, bringing wind speeds of up to 285 km hr−1 and wave heights of at least 10 m, and causing massive destruction to exposed reefs in the Palm Island Group. Following the cyclone, mean (± S.E.) hard coral cover ranged from just 2.1 (0.2) % to 5.3 (0.4) % on exposed reefs and no reproductively mature colonies of any species of Acropora remained. Although no fragments of Acropora were found at impacted exposed sites following the cyclone, small juvenile colonies of Acropora (<10 cm diameter) were present, suggesting that their small size and compact morphologies enabled them to survive the cyclone. By contrast, sheltered reefs appeared to be unaffected by the cyclone. Mean (± S.E.) hard coral cover ranged from 18.2 (2.4) % to 30.0 (1.0) % and a large proportion of colonies of Acropora were reproductively mature. Macroalgae accounted for 8 to 16% of benthic cover at exposed sites impacted by cyclone Yasi but were absent at sheltered sites. Mean (± S.E.) recruitment of acroporids to settlement tiles declined from 25.3 (4.8) recruits tile−1 in the pre-cyclone spawning event (2010) to 15.4 (2.2) recruits tile−1 in the first post-cyclone spawning event (2011). Yet, post-cyclone recruitment did not differ between exposed (15.2±2.1 S.E.) and sheltered sites (15.6±2.2 S.E.), despite the loss of reproductive colonies at the exposed sites, indicating larval input from external sources. Spatial variation in impacts, the survival of small colonies, and larval replenishment to impacted reefs suggest that populations of Acropora have the potential to recover from this severe disturbance, provided that the Palm Islands are not impacted by acute disturbances or suffer additional chronic stressors in the near future.  相似文献   

6.
Fishing and pollution are chronic stressors that can prolong recovery of coral reefs and contribute to ecosystem decline. While this premise is generally accepted, management interventions are complicated because the contributions from individual stressors are difficult to distinguish. The present study examined the extent to which fishing pressure and pollution predicted progress towards the Micronesia Challenge, an international conservation strategy initiated by the political leaders of 6 nations to conserve at least 30% of marine resources by 2020. The analyses were rooted in a defined measure of coral-reef-ecosystem condition, comprised of biological metrics that described functional processes on coral reefs. We report that only 42% of the major reef habitats exceeded the ecosystem-condition threshold established by the Micronesia Challenge. Fishing pressure acting alone on outer reefs, or in combination with pollution in some lagoons, best predicted both the decline and variance in ecosystem condition. High variances among ecosystem-condition scores reflected the large gaps between the best and worst reefs, and suggested that the current scores were unlikely to remain stable through time because of low redundancy. Accounting for the presence of marine protected area (MPA) networks in statistical models did little to improve the models’ predictive capabilities, suggesting limited efficacy of MPAs when grouped together across the region. Yet, localized benefits of MPAs existed and are expected to increase over time. Sensitivity analyses suggested that (i) grazing by large herbivores, (ii) high functional diversity of herbivores, and (iii) high predator biomass were most sensitive to fishing pressure, and were required for high ecosystem-condition scores. Linking comprehensive fisheries management policies with these sensitive metrics, and targeting the management of pollution, will strengthen the Micronesia Challenge and preserve ecosystem services that coral reefs provide to societies in the face of climate change.  相似文献   

7.
SYNOPSIS. Photosynthesis and calcification in zooxanthellatescleractinian corals and coral reefs are reviewed at severalscales: cellular (pathways and transport mechanisms of inorganiccarbon and calcium), organismal (interaction between photosynthesisand calcification, effect of light) and ecosystemic (communityprimary production and calcification, and air-sea CO2 exchanges). The coral host plays a major role in supplying carbon for thephotosynthesis by the algal symbionts through a system similarto the carbon-concentrating mechanism described in free livingalgal cells. The details of carbon supply to the calcificationprocess are almost unknown, but metabolic CO2 seems to be asignificant source. Calcium supply for calcification is diffusionalthrough oral layers, and active membrane transport only occursbetween the calicoblastic cells and the site of calcification.Photosynthesis and calcification are tightly coupled in zooxanthellatescleractinian corals and coral reef communities. Calcificationis, on average, three times higher in light than in darkness.The recent suggestion that calcification is dark-repressed ratherthan light-enhanced is not supported by the literature. Thereis a very strong correlation between photosynthesis and calcificationat both the organism and community levels, but the ratios ofcalcification to gross photosynthesis (0.6 in corals and 0.2in reef communities) differ from unity, and from each otheras a function of level. The potential effect of global climatic changes (pCO2 and temperature)on the rate of calcification is also reviewed. In various calcifyingphotosynthetic organisms and communities, the rate of calcificationdecreases as a function of increasing pCO2 and decreasing calciumcarbonate saturation state. The calculated decrease in CaCO3,production, estimated using the scenarios considered by theInternational Panel on Climate Change (IPCC), is 10% between1880 and 1990, and 9–30% (mid estimate: 22%) from 1990to 2100. Inadequate understanding of the mechanism of calcificationand its interaction with photosynthesis severely limits theability to provide an accurate prediction of future changesin the rate of calcification.  相似文献   

8.
The biological and economic values of coral reefs are highly vulnerable to increasing atmospheric and ocean carbon dioxide concentrations. We applied the COMBO simulation model (COral Mortality and Bleaching Output) to three major U.S. locations for shallow water reefs: South Florida, Puerto Rico, and Hawaii. We compared estimates of future coral cover from 2000 to 2100 for a “business as usual” (BAU) greenhouse gas (GHG) emissions scenario with a GHG mitigation policy scenario involving full international participation in reducing GHG emissions. We also calculated the economic value of changes in coral cover using a benefit transfer approach based on published studies of consumers'' recreational values for snorkeling and diving on coral reefs as well as existence values for coral reefs. Our results suggest that a reduced emissions scenario would provide a large benefit to shallow water reefs in Hawaii by delaying or avoiding potential future bleaching events. For Hawaii, reducing emissions is projected to result in an estimated “avoided loss” from 2000 to 2100 of approximately $10.6 billion in recreational use values compared to a BAU scenario. However, reducing emissions is projected to provide only a minor economic benefit in Puerto Rico and South Florida, where sea-surface temperatures are already close to bleaching thresholds and coral cover is projected to drop well below 5% cover under both scenarios by 2050, and below 1% cover under both scenarios by 2100.  相似文献   

9.
The coral reefs at the northernmost tip of Sabah, Borneo will be established under a marine protected area: the Tun Mustapha Park (TMP) by the end of 2015. This area is a passage where the Sulu Sea meets the South China Sea and it is situated at the border of the area of maximum marine biodiversity, the Coral Triangle. The TMP includes fringing and patch reefs established on a relatively shallow sea floor. Surveys were carried out to examine features of the coral reefs in terms of scleractinian species richness, and benthic reef assemblages following the Reef Check substrate categories, with emphasis on hard coral cover. Variation in scleractinian diversity was based on the species composition of coral families Fungiidae (n = 39), Agariciidae (n = 30) and Euphylliidae (n = 15). The number of coral species was highest at reefs with a larger depth gradient i.e. at the periphery of the study area and in the deep South Banggi Channel. Average live hard coral cover across the sites was 49%. Only 7% of the examined reefs had > 75% hard coral cover, while the majority of the reef sites were rated fair (51%) and good (38%). Sites with low coral cover and high rubble fragments are evidence of blast fishing, although the observed damage appeared old. Depth was a dominant factor in influencing the coral species composition and benthic reef communities in the TMP. Besides filling in the information gaps regarding species richness and benthic cover for reef areas that were previously without any data, the results of this study together with information that is already available on the coral reefs of TMP will be used to make informed decisions on zoning plans for conservation priorities in the proposed park.  相似文献   

10.
Although tropical coral reefs are one of the most spectrally complex habitats, there is relatively little known about colour vision of reef fish. In this study, we measured the spectral sensitivity of an endemic Hawaiian coral reef fish, Thalassoma duperrey (family Labridae), and assessed the possible role of visual sensitivity in mediating intraspecific communication. Electrophysiological recordings of compound action potentials from retinal ganglion cells were used to generate spectral sensitivity curves for specific wavelengths (380–620nm). We found at least 2 sensitivity peaks for the on response (max=460, 550nm). The off response lacked a short wavelength mechanism but a medium wavelength mechanism (max=545nm) and a longwave mechanism (max=570nm) were found. To quantify the visual stimulus provided by a conspecific individual, spectral reflectance from the colour pattern of T. duperrey was measured with a spectroradiometer. Luminance and spectral contrast were computed between colour patches of the pattern and between the patches and natural backgrounds (i.e., water and coral). Reflectance from the blue head and contrast from the blue, green and red patches matched the sensitivity maxima of T. duperrey, although this depended on the type of background. Our results indicate that T. duperrey should be able to visually detect the colour pattern of a conspecific fish and that T. duperrey's visual system is designed to enhance target detection in the coral reef habitat with matched and offset cone mechanisms.  相似文献   

11.
12.
Large areas of North American prairie have been planted with grasses introduced from Eurasia. We examined three strategies (herbicide, tilling, and nitrogen manipulation) for enhancing the establishment of seedlings of native species and suppressing the introduced grasses Agropyron cristatum (crested wheat grass) and Bromus inermis (smooth brome). Plots (5 × 15 m) were subjected to one of three levels of tilling (none, intermediate, complete) and four levels of nitrogen (none, intermediate, high, and sawdust added to immobilize nitrogen). Treatments were applied in a factorial design with twelve treatments and ten replicates. Seeds of 41 native species were drilled into the plots in May 1992. Following the failure of seeds to establish in 1992, a subplot (5 × 13 m) within each main plot was sprayed with the herbicide glyphosate in April 1993. The nitrogen treatments were repeated in Spring 1993. In August 1993, the density of native seedlings in sprayed subplots was 20 times that in unsprayed subplots. Within sprayed subplots, native seedling density and the cover of bare ground decreased significantly with increasing nitrogen availability. Plots receiving sawdust had significantly higher mean cover of bare ground and significantly lower concentrations of soil available nitrogen. Native seedling density was significantly higher in plots receiving the highest intensity of tilling. The responses of native seedlings to all these factors point to the importance of neighbor-free establishment sites as a prerequisite for prairie restoration.  相似文献   

13.
Radiotherapy often provides the only clinical recourse for those afflicted with primary or metastatic brain tumors. While beneficial, cranial irradiation can induce a progressive and debilitating decline in cognition that may, in part, be caused by the depletion of neural stem cells. Given the increased survival of patients diagnosed with brain cancer, quality of life in terms of cognitive health has become an increasing concern, especially in the absence of any satisfactory long-term treatments.To address this serious health concern we have used stem cell replacement as a strategy to combat radiation-induced cognitive decline. Our model utilizes athymic nude rats subjected to cranial irradiation. The ionizing radiation is delivered as either whole brain or as a highly focused beam to the hippocampus via linear accelerator (LINAC) based stereotaxic radiosurgery. Two days following irradiation, human neural stem cells (hNSCs) were stereotaxically transplanted into the hippocampus. Rats were then assessed for changes in cognition, grafted cell survival and for the expression of differentiation-specific markers 1 and 4-months after irradiation. Our cognitive testing paradigms have demonstrated that animals engrafted with hNSCs exhibit significant improvements in cognitive function. Unbiased stereology reveals significant survival (10-40%) of the engrafted cells at 1 and 4-months after transplantation, dependent on the amount and type of cells grafted. Engrafted cells migrate extensively, differentiate along glial and neuronal lineages, and express a range of immature and mature phenotypic markers.Our data demonstrate direct cognitive benefits derived from engrafted human stem cells, suggesting that this procedure may one day afford a promising strategy for the long-term functional restoration of cognition in individuals subjected to cranial radiotherapy. To promote the dissemination of the critical procedures necessary to replicate and extend our studies, we have provided written and visual documentation of several key steps in our experimental plan, with an emphasis on stereotaxic radiosurgey and transplantation.  相似文献   

14.
目的:探讨恒定磁场对日本三角涡虫(Dugesia japonica)无性横裂生殖及抗氧化酶活力的影响.方法:应用种群累积培养法,观察了恒定磁场对日本三角涡虫的种群增长、无性横裂生殖及涡虫体内超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活力的影响.结果:场强大小在200mT-500mT范围的恒定磁场能促进涡虫的无性横裂生殖,但恒定磁场显著抑制涡虫的SOD及CAT活力.结论:日本三角涡虫对恒定磁场的生理学响应较为敏感,可作为生物磁学研究适宜的实验材料.  相似文献   

15.
Our investigations were conducted from 1990 to 2002. Sampling of bottom sediments and biological objects, as well as photo and video shooting, were performed during scuba diving. The state of the environment and coral reef communities was assessed using the chemical–analytical, fluorometric, and luminometric methods, as well as the Ames test and the transect technique. The research results suggest that the spectrum and distribution pattern of persistent congeners of PCDD/Fs (dioxins) in bottom sediments are similar to those of the defoliant Agent Orange and that the bottom sediments are toxic and display photo inhibition and a mutagenic effect. The bottom of the bay is heavily silted throughout its depth. Many large dead colonies of corals without mechanical damage were observed everywhere. The total coverage by live corals in all sites investigated does not exceed 30%. Although, without a doubt, many factors contributed much to the disturbance of the bay ecosystems, the actual trigger for the degradation of the coral reefs seems to be the input of dioxin-containing chemicals used as defoliants during the American–Vietnamese war (Vietnam War).  相似文献   

16.
The use of acoustic signals by males during courtship and mating is well known. Nevertheless, their association with female unwillingness to mate is much less studied. In spiders, stridulation during sexual interactions is relatively common in some groups, but mainly restricted to males. In the pholcid spider Holocnemus pluchei, both sexes have stridulatory organs. The aims of the present work were (1) to establish whether female stridulation occurs during intra‐ and inter‐sexual interactions, (2) to determine whether female reproductive status affects the likelihood that she will stridulate and (3) to determine whether female stridulation is influenced by male sexual behaviour. We found that female stridulation usually occurs both during intrasexual interactions and, most frequently, during intersexual interactions. Females with more previous matings stridulated more frequently. Stridulation intensity was higher in females that did not accept new copulations compared with those that copulated. Female stridulation did not vary in elaborated and non‐elaborated courtship. Thus, females use stridulation to communicate levels of sexual receptivity. It is also possible that females use stridulation to indirectly assess male ability to persist and persuade.  相似文献   

17.
H Son  K Min  J Lee  GJ Choi  JC Kim  YW Lee 《Eukaryotic cell》2012,11(9):1143-1153
Fungi have evolved efficient metabolic mechanisms for the exact temporal (developmental stages) and spatial (organelles) production of acetyl coenzyme A (acetyl-CoA). We previously demonstrated mechanistic roles of several acetyl-CoA synthetic enzymes, namely, ATP citrate lyase and acetyl-CoA synthetases (ACSs), in the plant-pathogenic fungus Gibberella zeae. In this study, we characterized two carnitine acetyltransferases (CATs; CAT1 and CAT2) to obtain a better understanding of the metabolic processes occurring in G. zeae. We found that CAT1 functioned as an alternative source of acetyl-CoA required for lipid accumulation in an ACS1 deletion mutant. Moreover, deletion of CAT1 and/or CAT2 resulted in various defects, including changes to vegetative growth, asexual/sexual development, trichothecene production, and virulence. Although CAT1 is associated primarily with peroxisomal CAT function, mislocalization experiments showed that the role of CAT1 in acetyl-CoA transport between the mitochondria and cytosol is important for sexual and asexual development in G. zeae. Taking these data together, we concluded that G. zeae CATs are responsible for facilitating the exchange of acetyl-CoA across intracellular membranes, particularly between the mitochondria and the cytosol, during various developmental stages.  相似文献   

18.
Dandelions (genus Taraxacum) comprise a group of sexual diploids and apomictic polyploids with a complicated reticular evolution. Apomixis (clonal reproduction through seeds) in this genus is considered to be obligate, and therefore represent a good model for studying the role of asexual reproduction in microevolutionary processes of apomictic genera. In our study, a total of 187 apomictic individuals composing a set of nine microspecies (sampled across wide geographic area in Europe) were genotyped for six microsatellite loci and for 162 amplified fragment length polymorphism (AFLP) markers. Our results indicated that significant genetic similarity existed within accessions with low numbers of genotypes. Genotypic variability was high among accessions but low within accessions. Clustering methods discriminated individuals into nine groups corresponding to their phenotypes. Furthermore, two groups of apomictic genotypes were observed, which suggests that they had different asexual histories. A matrix compatibility test suggests that most of the variability within accession groups was mutational in origin. However, the presence of recombination was also detected. The accumulation of mutations in asexual clones leads to the establishment of a network of clone mates. However, this study suggests that the clones primarily originated from the hybridisation between sexual and apomicts.  相似文献   

19.
Agricultural intensification threatens grasslands worldwide and the restoration of grasslands from arable lands can at least partially counter this threat. We studied grassland restoration by following early successional changes of arthropod assemblages (spiders, Araneae; true bugs, Heteroptera; orthopterans, Orthoptera; and ground beetles, Carabidae) on 1‐ and 2‐year‐old restorations using arable lands and native grasslands as two ends of the succession timescale. To examine the changes in species composition among the habitat types, we used habitat affinity indices based on fidelity and/or specificity of the species. We found that the number of species did not differ between habitat types, while species composition changed markedly with time. Species richness was thus not adequate to detect favorable changes after grassland restoration. Habitat affinity indices, on the other hand, were useful to detect compositional changes caused by the increasing numbers of species characteristic of target grasslands as early as the second year after restoration. Habitat affinity indices are easy‐to‐use, easy‐to‐interpret measures of restoration success; therefore, we recommend their use as measures complementary to species richness and simple similarity. Our results show that sowing low‐diversity seed mixture followed by mowing and grazing can be particularly successful in grassland restoration in time periods as short as 2 years.  相似文献   

20.
One of the earliest recognized forms of sexual conflict was infanticide by males, which imposes serious costs on female reproductive success. Here I review two bodies of evidence addressing coevolved strategies of males and females. The original sexual selection hypothesis arguing that infanticide improves male mating success by accelerating the return of females to fertilizable condition has been generally supported in some taxa—notably, some primates, carnivores, rodents, and cetaceans—but not in other taxa. One result of recent research has been to implicate other selective benefits of infanticide by males in various taxa from insects to birds to mammals, such as acquisition of breeding status or improvement of the female breeding condition. In some cases, however, the adaptive significance of male infanticide remains obscure. The second body of data I review is arguably the most important result of recent research: clarifying the possible female counterstrategies to infanticide. These potential counterstrategies span diverse biological systems, ranging from sexual behavior (e.g., polyandrous mating), to physiology (e.g., the Bruce effect), to individual behavior (e.g., maternal aggression), to social strategies (e.g., association with coalitionary defenders of either sex). Although much remains to be studied, these current data provide compelling evidence of sexually antagonistic coevolution surrounding the phenomenon of infanticide.At its most elemental level, infanticide is the killing of a newborn individual by a conspecific. With the growing appreciation of its biological significance, however, infanticide came to be defined more broadly as any “behavior that makes a direct and significant contribution to the immediate death of an embryo or newly hatched or born member of the performer’s own species” (Mock 1984, p. 4) or “any form of lethal curtailment of parental investment in offspring brought about by conspecifics” (Hrdy and Hausfater 1984, p. xv). These definitions highlight the heterogeneous and variable nature of the phenomenon, which can be perpetrated by either sex, by parents or other kin, by individuals unrelated to the victim, in a wide variety of social and mating systems, under a range of seasonal or aseasonal breeding regimes, and across diverse taxa straddling vertebrates and invertebrates.One adaptive form of infanticide—the killing of infants by unrelated males—is arguably the archetype of sexual conflict. In 450 BCE, Herodotus not only documented the behavior among Egyptian cats, but explained it as a male “trick” to obtain sexual access to females otherwise preoccupied with maternal duties (Delibes et al. 2012). Among the myriad ideas inaugurating sociobiology in the 1970s, the hypothesis that infanticide is a male strategy that improves reproductive success at the expense of female fitness (Hrdy 1974) constituted one of the first demonstrations of the “battle of the sexes” theory developed by Williams (1966) and Trivers (1972). Partly because of the controversy surrounding the appearance of this hypothesis (Rees 2009), however, subsequent research focused more on male strategy than on the other party in this sexual dialectic, the female. Thus, field and laboratory research has helped to establish its many forms and conditional occurrence, describe its distribution across taxa, and clarify its adaptive significance, but it is only relatively recently that female counterstrategies have become the subjects of rigorous study, even though their potential importance was grasped early on (Hrdy 1979).In this article, I review selected aspects of this body of data and analysis. My focus is on nonparental male infanticide targeting dependent young—in mammals, nursing individuals—as opposed to older, weaned offspring, the killing of which is variably rendered “juvenilicide,” “pedicide,” or “filicide” (e.g., Agoramoorthy and Mohnot 1988; Palombit 2014, in press).  相似文献   

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