Cannibalism, among Other Solutions of Adaption, in Habitats Where Food Is Not Available for Salamandra infraimmaculata Larvae Diet in Breeding Places in Xeric Habitats

The present study examines the inherent flexibility in the feeding responses of S. infraimmaculata larvae to various breeding places. In addition, the study examines the hypothesis that in dry conditions, the water breeding places are the limiting factor for the survival and completion of the life cycle of populations of S. infraimmaculata. In the breeding sites, the food for larvae is not available, and cannibalism is the specific adaptation for larvae to grow and complete metamorphosis. S. infraimmaculata larvae feed on various invertebrates in different habitats, and cannibalism involves the adaptation to breeding places where food is not available. The growth only by cannibalism as the only way to adapt to these habitats because no food is found in breeding places at the southern border of its distribution is described here for the first time, not only in salamanders but in other animals as well.

A Conceptual Approach for Cannibalism Between Goods

The launching of a new product is an essential strategy for the survival and success of a company. However, in certain cases, it can reduce the results obtained by other products of the same company. This fact is named ＂cannibalism＂. Following by a review of the literature on cannibalism between goods, this paper outlines a conceptual approach, showing the way it happens, its impacts, and the possibility of its uses as a marketing tool. A new product should, wherever possible, be carefully designed to avoid cannibalizing old products, unless this process is carefully planned. Concludes that creating and launching of new products are critical to companies who want to stand out next to their markets and need to survive over time. A lot of new products launched each year, coupled with the fact that most are line extensions already worked by companies, so we assume that the occurrence of cannibalism is common, or that a significant amount of resources are designed to prevent or dilute it. There is a high probability of transfer of results obtained by established products to new products, since similarity between

Cannibalism and the Applicablity on Brand Name Translation

Good brand name translation involves knowledge and expertise from many disciplines,such as linguistics,translation studies,marketing,aesthetics,psychology,law,etc.It is really an interdisciplinary practice that requires strenuous research and experience.In addition,the research methodology thereof is also quite problematic.This paper aims at bringing a latest translation theory—cannibalism into brand name translation and test its applicability in brand name translation practice.

A thelytokous predatory mite is more cannibalistic towards distant kin

Kin recognition has been widely observed in various taxa.Cannibalism avoidance may be a strong driver for the evolution of kin recognition,as it may avoid a reduction in inclusive fitness.Kin recognition has recently been observed in a generalist phytoseiid,Amblyseius herbicolus(Acari:Phytoseiidae).This study experimentally examined the degree of relatedness needed between prey larvae and cannibal adults of A.herbicolus for the occurrence of kin discrimination.The adults were individually placed in enclosed arenas with two prey,a daughter and a more distant related larva,to observe their cannibalizing choice.The adults of A.herbicolus did not discriminate between close relatives(daughter versus niece)but preferably cannibalized more distant kin(i.e.,first and second cousins once removed).Phenotype matching and familiarization seem prominent as recognition mechanisms used by A.herbicolus adults.The effect of learning on kin recognition through prior contact in A.herbicolus requires further investigation.Studies on other adaptive functions of kin recognition of A.herbicolus,such as cooperation and parental care,may provide meaningful insights.

Exploring the dynamics of a Holling-Tanner model with cannibalism in both predator and prey population

Cannibalism is an intriguing life history trait, that has been considered primarily in the predator, in predator-prey population models. Recent experimental evidence shows that prey cannibalism can have a significant impact on predator-prey population dyna- mics in natural communities. Motivated by these experimental results, we investigate a ratio-dependent Holling-Tanner model, where cannibalism occurs simultaneously in both the predator and prey species. We show that depending on parameters, whilst prey or predator cannibalism acting alone leads to instability, their joint effect can actually stabilize the unstable interior equilibrium. Furthermore, in the spatially explicit model, we find that depending on parameters, prey and predator cannibalism acting jointly can cause spatial patterns to form, while not so acting individually. We discuss ecologicalconsequences of these findings in light of food chain dynamics, invasive species control and climate change.

Amino acid compounds released by the giant freshwater prawn Macrobrachium rosenbergii during ecdysis:a factor attracting cannibalistic behaviour?

Ecdysis is a comm on phe nomenon that happe ns throughout the life phase of the giant freshwater prawn Macrobrachium rosenbergii.It is vital to better understand the correlation between cannibalism and biochemical compound that exists during the moulting process.The objective of the present study was to determine the amino acid profile released by M.rosenbergii during the ecdysis process that promotes cannibalism.To accomplish this,changes in amino acid levels(total amino acid(TAA)and free amino acid(FAA))of tissue muscle,exoskeleton,and sample water of culture medium from the moulting(E-stage)and non-moulting(C-stage)prawns were analysed using highperformanee liquid chromatography(HPLC).Comparison study revealed that among the TAA compounds,proline and sarcosine of tissues from moulting prawn were found at the highest levels.The level of FAA from water that contains moulting prawns(E-stage)was dominated by tryptophan and proline.Significant values obtained in the present study suggested that these amino acid compounds act as a chemical cue to promote cannibalism in M.rosenbergii during ecdysis.The knowledge of compositions and compounds that were released during the moulting process should be helpful for better understanding of the mechanism and chemical cues that play roles on triggering cannibalism,and also for future dietary man ipulati on to improve feeding efficie ncies and feeding man agement,which in directly impacts productivity and profitability.

Time to feed： How diet, competition, and experience may influence feeding behaviour and cannibalism in wood frog tadpoles Lithobates sylvaticus

Wood frog Lithobates sylvaticus tadpoles develop in temporary wetlands where high population densities can force tadpoles into aggregations that intensify competition and can lead to cannibalism. However, chemical alarm cues released from injured conspecifics could also dissuade cannibalism. The purpose of this study was to test mechanisms that may influence can- nibalistic behaviour. We tested whether the tendency of tadpoles to consume conspecifics would increase with the presence of competition and/or cues of profitable diets. Tadpoles placed in 1L experimental containers were tested for feeding initiation times of multiple diets, including conspecific tissues and conspecific tissues combined with chemical cues from the alternative diets （brine shrimp and comrneal）. Tadpoles were tested in the presence and absence of a competitor, and at multiple times over the course of the study. Tadpoles exhibited an altered response to diets over time; however the presence of a competitor reduced re- sponse times to all diets including conspecific tissues. Similarly, the presence of specific diets also reduced the response time of tadpoles to conspecific tissues. These results suggest competition among feeding tadpoles could result in aggressive behaviour leading to indiscriminate predation and cannibalism [Current Zoology 60 （5）： 571-580, 2014 ].

Cannibalism in the pea aphid, Acyrthosiphon pisum

Previous observations of cannibalism have been made in the aphid Acyrthosiphon pisum （L.）： this article seeks to quantify factors contributing to such be- haviors. We observed and quantified the responses of a number of clones and life stages to varying levels of starvation, in the form of increasingly desiccated Vicafaba L. plants （receiving 50, 25, or 10 mL every second day） or a complete absence of host plant. We found that, while the longest incidences of cannibalism are carried out by juveniles （F = 3.45, P = 0.019, df = 3） and targeted at adults, the starvation treatments had the most significant effect on the prevalence of cannibalism in mature A. pisum （F ---- 2.24, P = 0.025, df = 9）. Furthermore, there was no difference between the prevalence or dura- tion of cannibalistic activities within and between different clones （P 〉 0.05 in all cases）, though juveniles were more likely to target unrelated aphids （V = 6 112, P = 0.011）, and spent more time feeding on aphids from the same culture （V = 6 062, P = 0.018）.

Reducing feather pecking and cloacal cannibalism by providing layer breeders with nest boxes in colony cages for natural mating

Colony cages for natural mating have been applied on many layer breeder farms.However,feather pecking and cloacal cannibalism are considered as prominent problems for these systems.This study aimed to investigate the effects on feather pecking and vent pecking behaviors by providing layer breeders with nest boxes(0.90 m L×0.40 m W×0.60 m H)in colony cages for natural mating(4.80 m L×1.20 m W×0.71 m H).Video recording and artificial observation were adopted.The results showed that the usage of nest boxes gradually increased from the beginning of nest boxes providing at the age of 37 weeks to the end of the experiment at the age of 55 weeks.The utilization rates of nest boxes were 36.75%,44.75%and 50.38%at the ages of 41 weeks,47 weeks and 53 weeks,respectively.The hens in the cages without nest boxes showed significantly more frequent gentle feather pecks(both given and received)than hens in the cages with nest boxes at the ages of 41 weeks,47 weeks and 53 weeks.A decreasing trend of gentle feather pecking frequency(both given and received)was found with the increasing age for both the two groups.No significant difference was found in the number of given or received severe feather pecks at the age of 41 weeks.The hens in the cages without nest boxes showed a significantly higher frequency of given and received severe feather pecks than hens in the cages with nest boxes at the ages of 47 weeks and 53 weeks(p<0.05).Both cannibalistic injury occurrence and mortality rate in the cages with nest boxes were significantly lower than those in the cages without nest boxes.In conclusion,providing nest boxes in colony cages for natural mating could decrease abnormal pecking behaviors and improve animal welfare conditions of layer breeders.

Global analysis of a juvenile-adult model for cannibalistic species

Cannibalism is a life trait occurring in a wide variety of species.To describe the population dynamics of cannibalistic species,we develop a stage-structured population model in which axJults prey on juveniles with a Holling type I functional response.We make a rigorous analysis of the global dynamics in the model.The results of theoretical analysis show that the model has no boundary equilibrium other than the extinction one since juveniles and adults are cooperative(adults reproduce juveniles and juveniles grow into adults).Under certain conditions,the model has multiple interior equilibria and exhibits several types of bistable dynamics,in which different initial densities of juveniles and adults produce different long-term outcomes.

Who eats whom,when and why?Juvenile cannibalism in fish Asian seabass

While juvenile cannibalism plays an important role in the evolution of organisms in natural populations,it is a serious problem in aquaculture.A number of genetic and environmental factors result in different rates of cannibalism.Whether there is kin recognition in juvenile cannibalism in fish is poorly understood.We studied cannibalism and kinship recognition in juveniles of Asian seabass using molecular parentage analysis with polymorphic microsatellites.In the three mass crosses,under an ordinary feeding scheme without size grading,the rate of juvenile loss due to cannibalism was 1.08% per day.In the group without feeding for 24 h,2.30%±0.43% of offspring per day were lost within 24 h due to cannibalism.We detected that juveniles avoided cannibalizing their siblings when they were not hungry,whereas cannibalism among siblings increased when they were hungry.These data suggest that there is kin discrimination in fish cannibalism.Raising genetically closely related offspring in the same tanks and appropriate levels of feeding may reduce the rate of cannibalism.We hypothesized that the chemical cues for kin discrimination might be secreted by fish skins.To test this hypothesis,we analyzed gene expression profiles in the skins of juveniles under slightly and very hungry conditions using RNA sequencing and bioinformatics analysis.Genes differently expressed under slightly and very hungry conditions were identified.Among them,genes from the trypsin family were significantly downregulated under starved conditions,suggesting that they may play a role in kin discrimination.

A model of inter-cohort cannibalism and paedomorphosis in Arizona Tiger Salamanders, Ambystoma tigrinum nebulosum

Cannibalism is widespread in size-structured populations. If cannibals and victims are in different life stages, dominant cohorts of cannibals can regulate recruitment. Arizona Tiger Salamanders, Ambystoma tigrinum nebulosum, exhibit facultative paedomorphosis in which salamander larvae either metamorphose into terrestrial adults or become sexually mature while still in their larval form. Although many salamanders exhibit cannibalism of larvae, the Arizona Tiger Salamander also exhibits cannibalism of young by the aquatic adults. We formulate a differential equations model of this system under the assumption that the terrestrial adults do not impact the system beyond their contribution to the birth of young larvae. We establish non-negativity, boundedness and persistence of the salamander population under certain assumptions. We consider the equilibrium states of the system in the presence or absence of a birth contribution from the terrestrial or metamorph adults. Constant per capita paedomorphosis leads to asymptotically stable equilibria. The per capita paedomorphosis rate of the larvae must be density dependent in order for periodic solutions to exist. Furthermore, the stage transition rate must be sufficiently decreasing in order to guarantee the existence of an unstable equilibrium. Periodic solutions are only possible in the presence of a unique non-trivial unstable equilibrium. Our results conform to previous theory on paedomorphosis which suggests general applicability of our results to similar systems.

Cuticular compounds inhibit cannibalism of early-instar spiderlings by pulli-carrying Pardosa pseudoannulata females

Cannibalism is common in spiders.Wolf spider(Lycosidae)females,which exhibit extensive maternal care,have been reported to cannibalize less when they are carrying egg sacs and juveniles.In a laboratory experiment,we demonstrated that cannibalism of early-instar spiderlings(EIS)by a wolf spider(Pardosa pseudoannulata)mother was almost completely inhibited when she was carrying spiderlings.Compared with virgin and mated-females,mother spiders tolerated more and predated fewer spiderlings,including gregarious pulli and newly dispersed spiderlings(NDS).Cannibalism of EIS by females during their reproductive period exhibited a V-shaped pattern,with a gradual decrease from the egg sac-carrying to pulli-carrying(PC)stage,and a recovery from the PC stage to post-reproductive(PR)stage.Notably,there was 0 cannibalism at the PC stage.PC females exhibited no interest in pulli,while PR females were attracted to and predated pulli and NDS as they did their natural prey,Nilaparvata lugens.Interestingly,PC females captured and released NDS in a foraging assay,although attraction was observed from olfactometer measurements.PC mothers possessed a cuticular volatile profile that was closer to that of pulli and NDS than to that of PR females.Moreover,NDS cuticular extract provoked an electrophysiological response in legs of PC females.Therefore,cuticular compound-mediated chemical communication may be involved in inhibiting cannibalism of EIS by spider mothers,and especially in eliminating cannibalism by PC mothers.Future studies will aim to characterize the specific cuticular compounds and chemoreception mechanism in females,which will facilitate our understanding of intraspecific recognition and cannibalism in spiders.

Adult cannibalism in an oligophagous herbivore, the Colorado potato beetle

Cannibalism, or intraspecific predation, can play a major role in changing individual fitness and population processes. In insects, cannibalism frequently occurs across life stages, with cannibals consuming a smaller or more vulnerable stage. Predation of adult insects on one another is considered to be uncommon. We investigated adult cannibalism in the Colorado potato beetle, Leptinotarsa decemlineata （Say）, which is an oligophagous herbivore specializing on plants in family Solanaceae, and an important agricultural pest. Under laboratory conditions, starvation and crowding encouraged teneral adults to feed upon each other, which reduced their weight loss during the period of starvation. However, pupae were attacked and consumed before adults. Injured beetles had a higher probability of being cannibalized than intact beetles. Males were more frequently attacked than females, but that appeared to be a function of their smaller size rather than other gender-specific traits. Cannibalizing eggs at a larval stage did not affect beetle propensity to cannibalize adults at an adult stage. When given a choice between conspecific adults and mealworrns, the beetles preferred to eat conspecifics. Cannibalistic behavior, including adult cannibalism, could be important for population persistence in this species.

Oviposition behavior of the mirid Macrolophus pygmaeus under risk of intraguild predation and cannibalism

Zoophytophagous mirid species,that feed and develop either on prey or plant resources,are often found simultaneously on the same host.Hence,these species can engage in both intraguild predation and cannibalism,which can pose a threat to mirid eggs.Ovipositing females may respond to such risks of predation on their eggs by reducing the number of eggs laid or selecting safer oviposition sites.We tested the oviposition behavior of Macrolophus pygmaeus(Rambur)(Hemiptera:Miridae)females under the risk of cannibalism by M.pygmaeus males and intraguild predation by Nesidiocoris tenuis(Reuter)males(Hemiptera:Miridae)under laboratory conditions.Intraguild predators and cannibals were introduced during or after the oviposition period.The number of eggs laid(using counts of newly hatched nymphs)and their proportion on each part of a tomato plant were both measured.The results reveal that only cannibalism by M.pygmaeus males after the period of oviposition significantly decreased the number of hatched eggs.Cannibalism thus represents a greater risk to mirid eggs than intraguild predation.The M.pygmaeus female responded to the presence of potential intraguild predators(or competitors)by decreasing the nu mber of eggs laid in the upper leaves.The results suggest that M.pygmaeus females avoid competition by N.tenuis,by laying fewer eggs on upper leaves.Cannibalism could regulate zoophytophagous predator populations under prey scarcity conditions and minimize the risk of crop damage associated with those biological control agents.

Male opportunistic mating increases with intensity of female sexual cannibalism in 3 web-building spiders

Sexual conflict is common in animals,and female sexual cannibalism represents an extreme form of sexual conflict.Males in many species have evolved a variety of strategies to circumvent or decrease the risk of female sexual cannibalism.Opportunistic mating,by which a male mates with a female when she is disturbed or when she is feeding or undertaking moulting,is one of such kinds of strategies,and widely occurs in many animals,especially in spiders.However,whether the occurrence of male opportunistic mating depends on the intensity of female sexual cannibalism remains largely unexplored.We predicted a positive correlation between them.In this study,we tested this prediction by performing a series of mating trials in the laboratory using 3 species of web-building spiders with different intensities of female sexual cannibalism:Nephila pilipes,Nephilengys malabarensis,and Parasteatoda tepidariorum.We found that the occurrence of male opportunistic mating was positively,though not statistically significantly,correlated with the intensity of female sexual cannibalism,thus supporting our hypothesis.All together,we provide evidence that male opportunistic mating may have evolved to respond to the selection pressure posed by female sexual cannibalism.

Differential pricing and production strategies for heterogeneous products under cannibalization and promotional effects

This study examines the optimal pricing and production strategy of a closed-loop supply chain consisting of a manufacturer, a recycler, and consumers. Considering the cannibalization and promotion effects of remanufactured products on new and secondhand products, we constructed Stackelberg game models under different scenarios. We analyze the impact of the changes in the two effects on the optimal prices and production strategies of the manufacturer and recycler, as well as their countermeasures. We find that (i) how the cannibalization and promotional effects influence the manufacturer and the recycler's pricing and production strategies differ under different scenarios;(ii) when the two effects exceed a threshold, the manufacturer abandons new or remanufactured products, and the recycler prefers to stop production on its new products or continue to remanufacture products;and (iii) the two effects always reduce the profits of the manufacturer and increase the profits of the recycler.

Effect of multiple delays on the dynamics of cannibalistic prey-predator system with disease in both populations

In the present paper, we investigate a prey-predator system with disease in both prey and predator populations and the predator population is cannibalistic in nature. The model is extended by introducing incubation delays in disease transmission terms. Local stability analysis of the system around the biologically feasible equilibria is studied, The bifurcation analysis of the system around the interior equilibrium is also studied, The sufficient conditions for the permanence of the system are derived in the presence of delays. We observe that incubation delays have the ability to destabilize the cannibalistic prey-predator system. Finally, we perform numerical experiments to substantiate our analytical findings.

Comparative transcriptomics highlights convergent evolution of energy metabolic pathways in group-living spiders

Although widely thought to be aggressive, solitary,and potentially cannibalistic, some spider species have evolved group-living behaviors. The distinct transition provides the framework to uncover groupliving evolution. Here, we conducted a comparative transcriptomic study and examined patterns of molecular evolution in two independently evolved group-living spiders and twelve solitary species. We report that positively selected genes among groupliving spider lineages are significantly enriched in nutrient metabolism and autophagy pathways. We also show that nutrient-related genes of group-living spiders convergently experience amino acid substitutions and accelerated relative evolutionary rates. These results indicate adaptive convergence of nutrient metabolism that may ensure energy supply in group-living spiders. The decelerated evolutionary rate of autophagy-related genes in group-living lineages is consistent with an increased constraint on energy homeostasis as would be required in a group-living environment. Together, the results show that energy metabolic pathways play an important role in the transition to group-living in spiders.