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1.
Summary. Recent studies indicate that amphibian eggs are capable of hatching plasticity in response to chemical cues released by predators
feeding on conspecific eggs or larvae. However, information is scarce on the relative importance of predator and conspecific
cues in such a process. In particular, no attempt has been made to compare the effects of embryonic exposures to chemical
cues indicative of a predation risk for eggs and larvae, although both life stages can co-occur in natural habitats. In this
context, common frog embryos (Rana temporaria) were raised until hatching in the presence of crushed conspecific extracts from eggs and tadpoles to assess their respective
influences on some hatching and larval traits. While a significant delay in hatching time was observed in embryos exposed
to chemical cues from tadpole extract, this life-history shift appeared unaffected by embryonic exposure to egg extract. Hatchlings
derived from eggs incubated in the presence of both conspecific extracts showed a significantly greater weight than unexposed
controls. However, such an effect was no longer apparent 15, 30 and 50 days after hatching, suggesting that embryonic exposure
to chemical cues from damaged conspecific eggs and tadpoles has no influence on larval growth. Lastly, morphological measurements
performed on hatchlings and older tadpoles (15, 30 and 50 days old) revealed no significant effect of embryonic treatments
on the shape of body and tail. 相似文献
2.
Juan Camilo Marín Loaiza Carlos L. Céspedes Till Beuerle Claudine Theuring Thomas Hartmann 《Chemoecology》2007,17(2):109-115
Summary. The occurrence of pyrrolizidine alkaloids (PAs) in Pittocaulon (ex Senecio) praecox (Asteraceae) a species endemic to Mexico was established. The aboveground plant organs contain the 1,2-saturated monoester
7-angeloyl-dihydroxyheliotridane together with a small proportion of its 9-angeloyl isomer as major alkaloid. The monoesters
are accompanied by the macrocyclic otonecine derivative senkirkine. Roots contain only related macrocyclic PAs with senecionine,
senkirkine and platyphylline as major components; monoesters are absent. The broom-like succulent stems of P. praecox are infested by the scale insect Ceroplastes albolineatus conspicuously visible by its huge wax cover. All life-history stages, i.e. females, eggs, first instar nymphs (crawlers)
and the wax cover were found associated with PAs. The measured PA concentrations clearly indicate sequestration. The highest
PA concentrations (mg / g dry weight) reached are: mature females, 0.44; eggs, 0.58; crawlers, 0.37; wax cover, 0.08. The
host plant as well as in the infesting scale insect contain the PAs exclusively as free bases. As a phloem-feeder C. albolineatus must acquire the PAs with the ingested phloem sap. This appears plausible since in Senecio species PA are transmitted and circulated through the phloem path. It is suggested that PAs may protect particularly the
crawlers as the most endangered stage in the life-cycle of the scale insect. 相似文献
3.
Fleur E. Champion de Crespigny Nina Wedell 《Behavioral ecology and sociobiology》2007,61(8):1229-1235
The maternally inherited bacterium Wolbachia pipientis generates strong reproductive incompatibilities between uninfected females and infected males (cytoplasmic incompatibility),
significantly reducing both female and male reproductive success. Such fitness costs are thought to place selective pressure
on hosts to evolve pre-copulatory preferences for mating with compatible mates, thereby enabling them to avoid the reproductive
incompatibilities associated with Wolbachia. Therefore, uninfected females are predicted to prefer mating with uninfected males, whereas infected males are predicted
to prefer mating with infected females. Despite these predictions, previous investigations of pre-copulatory mate preferences
in Wolbachia-manipulated Drosophila have not found evidence of female preference for uninfected or compatible males. However, none of these studies utilised
a design where focal individuals are provided with a simple choice in a relatively non-competitive situation. We examined
both female and male pre-copulatory mate preference based on mate infection status in Drosophila simulans and D. melanogaster using simple choice assays involving between 30–50 replicates per treatment. Although we found no evidence of female pre-copulatory
mate preferences in either species, male D. simulans exhibited some preference for mating with females of the same infection status. However, this preference was not evident
when we repeated the experiment to confirm this finding. Consequently, we conclude that neither male nor female D. melanogaster and D. simulans exhibit significant Wolbachia-associated pre-copulatory mate preferences. 相似文献
4.
Summary. Males of dacine tephritids, Bactrocera carambolae and B. dorsalis are strongly attracted to, and compulsively feed on methyl eugenol (ME), a potent attractant for many Bactrocera species. While ME was shown to be biotransformed into phenylpropanoids, 2-allyl-4,5-dimethoxyphenol and (E)-coniferyl alcohol, and temporarily stored in the rectal gland of male B. dorsalis prior to release during courtship at dusk, B. carambolae male produces only the latter compound along with its de novo synthesized pheromone components. Both species were also shown to have different age-related response, sensitivity and consumption
levels of ME. Here, we monitored and compared temporal changes in the accumulation profiles of these phenylpropanoids by the
two sibling species, with male rectal glands being individually excised at different time intervals from 15 minutes to 20
days after initial ME feeding and analysed quantitatively. Results are discussed in light of plant-fruit fly co-evolution
relationship. 相似文献
5.
Nestmate recognition for eggs in the honeybee (<Emphasis Type="Italic">Apis mellifera</Emphasis> L.)
Christian W. W. Pirk Peter Neumann Randall Hepburn 《Behavioral ecology and sociobiology》2007,61(11):1685-1693
Colony integrity is fundamental to social insects and is threatened by the reproduction of non-nestmates. Therefore, discrimination
between eggs derived from nestmates and non-nestmates would constitute an adaptation to prevent exploitation of the entire
cooperative group by unrelated individuals. The removal of nestmate and non-nestmate queen and worker-laid eggs was evaluated
in honeybees using colonies of Apis mellifera capensis to test female and of A. m. scutellata to test male eggs. The data show that honeybees can distinguish between nestmate and non-nestmate eggs of both sexes. Moreover,
non-nestmate female queen-laid eggs were removed significantly faster than nestmate female worker-laid eggs in A. m. capensis, indicating that nestmate recognition cues can override caste-specific ones. While the experimental manipulation accounts
for 37.2% (A. m. scutellata) or 1.6% (A. m. capensis) of variance in relation to egg removal, nestmate recognition explains 33.3% for male eggs (A. m. scutellata) and 60.6% for female eggs (A. m. capensis), which is almost twice as high as the impact of caste (16.7% A. m. scutellata; 25% A. m. capensis). Our data show a stronger effect of nestmate recognition on egg removal in the honeybee, suggesting that cues other than
caste-specific ones (viability/kin) can dominate egg removal behavior. In light of intraspecific social parasitism, preventing
the reproduction of unrelated individuals (group selection) rather than preferring queens’ eggs (kin selection) appears to
be the driving force behind the evolution of egg removal behavior in honeybees. 相似文献
6.
Nataliya Voloshchuk Mona Knop Thomas Colby Erich Kombrink Lothar Hennig Diana Hofmann Dieter Sicker Andrej Gryganski Margot Schulz 《Chemoecology》2007,17(1):1-12
Summary. Doratomyces stemonitis (Hyphomycetales, Dematiaceae) is a saprotrophic fungus belonging to the mycobiota of the cereal rhizosphere. The fungus is
able to metabolize benzoxazolin-2-(3H)-one and a variety of its derivatives including higher plant detoxification products, microbial degradation products and
the chemically rather stable 2-amino-(3H)-phenoxazin-3-one. D. stemonitis can use all of these compounds as sole C-sources but their utilization, especially that of microbial degradation products
and 2-amino-(3H)-phenoxazin-3-one, seems to be highly energy consuming, resulting in slow mycelium growth and a change of colony morphology.
Benzoxazolin-2-(3H)-one derived compounds induce the synthesis of different isoforms of a glycosylated protein with sequence homologies to the
endo-1,3-β-glucanase Asp f2, an allergen from Aspergillus fumigatus and other Asp f2-like proteins e.g., from Verticillium dahliae or PRA1 antigen from Candida albicans. The induction of the protein is regarded as a stress response. 相似文献
7.
A conflict over male production arises in social insects where workers are able to lay unfertilized male eggs. This happens
because each female (queen or worker) is most closely related to her own sons and is thus predicted to reproduce. The conflict
is modulated by worker policing where workers prevent each other from reproducing by aggression or egg cannibalism. In this
study, we show that in the ant Formica fusca, worker policing occurs by egg cannibalism rather than by overt aggression among workers. Furthermore, we show that, contrary
to bees, wasps and other ant species, egg discrimination in F. fusca is not based only on a universal queen signature chemical and that nest mate recognition of eggs occurs. 相似文献
8.
Summary. The formicine ant Paratrechina longicornis is known for its extremely opportunistic foraging behaviour. Only a single trail pheromone source, the rectum, was previously
described from this ant. Our detailed examination of this ant’s chemical communication system revealed the presence of at
least four sources of pheromones. Rectum, poison sac, and Dufour gland contain orientation components with decreasing effectiveness
and persistence (in the sequence mentioned) as well as attractants with increasing effectiveness. Furthermore, the mandibular
gland contains repellents, and a releaser of defensive behaviour. This set of various signals of different strength and persistence
allows an extraordinary degree of flexibility and efficiency in the collective behaviour of P. longicornis, especially food exploitation, and thus may contribute to this insect’s overall ecological success. 相似文献
9.
Eldridge S. Adams Lynn Atkinson Mark S. Bulmer 《Behavioral ecology and sociobiology》2007,61(8):1195-1201
Loss of aggression between social groups can have far-reaching effects on the structure of societies and populations. We tested
whether variation in the genetic structure of colonies of the termite Nasutitermes corniger affects the probability of aggression toward non-nestmates and the ability of unrelated colonies to fuse. We determined the
genotypes of workers and soldiers from 120 colonies at seven polymorphic microsatellite loci. Twenty-seven colonies contained
offspring of multiple founding queens or kings, yielding an average within-colony relatedness of 0.33. Genotypes in the remaining
93 colonies were consistent with reproduction by a single queen and king or their progeny, with an average within-colony relatedness
of 0.51. In standardized assays, the probability of aggression between workers and soldiers from different colonies was an
increasing function of within-colony relatedness. The probability of aggression was not affected significantly by the degree
of relatedness between colonies, which was near zero in all cases, or by whether the colonies were neighbors. To test whether
these assays of aggression predict the potential for colony fusion in the field, we transplanted selected nests to new locations.
Workers and soldiers from colonies that were mutually tolerant in laboratory assays joined their nests without fighting, but
workers and soldiers that were mutually aggressive in the assays initiated massive battles. These results suggest that the
presence of multiple unrelated queens or kings promotes recognition errors, which can lead to the formation of more complex
colony structures. 相似文献
10.
Marissa L. Parrott Simon J. Ward Peter D. Temple-Smith 《Behavioral ecology and sociobiology》2007,61(7):1075-1079
Females show mate preferences for males that are genetically dissimilar to themselves in a variety of taxa, but how females
choose these males is not clearly understood. In this study, we examined the effects of olfactory stimuli and genetic relatedness
on female mate choice in a small carnivorous marsupial, the agile antechinus (Antechinus agilis), during two breeding seasons. Captive female antechinus in oestrus were provided with a combination of male urine and body
scent from two novel males, one more genetically similar and one more dissimilar to the females, in a Y-maze olfactometer.
Genetic relatedness between females and pairs of males was determined using highly polymorphic, species-specific, microsatellite
markers. Females consistently chose to visit the scents of males that were genetically dissimilar to themselves first, spent
significantly more time near the source of those scents and showed more sexual and non-exploratory behaviours near those scents.
These data demonstrate that chemosensory cues are important in mate choice in the agile antechinus and that females prefer
males that are genetically dissimilar to themselves. 相似文献
11.
Offspring should be selected to influence maternal effort to maximize their own fitness, whereas mothers are selected to limit
investment in present progeny. In mammals, this leads to a conflict over the amount of milk provided and the timing of weaning.
The intensity and time course of such conflict has so far mostly been investigated experimentally in altricial rodents. However,
it is expected that offspring options for conflict will depend on developmental state. We therefore investigated in the highly
precocial domestic guinea pig (Cavia aperea f. porcellus) who decides over nursing performance and weaning and how pup state influences these decisions. Specifically, we tested whether
a threshold mass of pups predicts weaning time. By exchanging older litters against neonates and vice versa, we produced a
situation in which females differed in lactational stage from the cross-fostered pups. Our results indicate that females decide
about the timing of weaning, as cross-fostered younger pups were weaned at a much younger age than controls and older pups
benefited from continuing lactation of foster mothers. Growth rates did not differ in the treatment groups, and different
weaning ages resulted in differing weaning mass refuting the hypothesis that weaning is based on a threshold mass of offspring.
This constitutes clear evidence that in a precocial rodent, the guinea pig, decisions about maternal care are primarily determined
by maternal state and little influenced by pup state despite the extreme precociality of offspring. We suggest that precocial
pups show little resistance to early weaning when food is abundant, as they reach sufficient nutritional independence by the
middle of lactation to enable independent survival. 相似文献
12.
Olivier Roux Charles Gers Josèphe Nathan Tene-Ghomsi Laurence Arvanitakis Dominique Bordat Luc Legal 《Chemoecology》2007,17(1):13-18
Summary. Cotesia plutellae is a specialist parasitoid of Plutella xylostella. This specificity is potentially under the control of several factors before and after oviposition. Thereby, the stimuli
that lead female parasitoids to host locations and to oviposition, might be at the basis of the specificity. We explore here
the response of C. plutellae females exposed to host cuticular lipids. A total cuticular lipid extract of host caterpillars was fractionated into a hydrocarbon
fraction and a non-hydrocarbon fraction. Neither fraction alone had any effect on oviposition behaviour in C. plutellae but the hydrocarbon fraction alone did seem to have a positive effect on the rate of antennal contact by the females. To
induce oviposition behaviour, both fractions were necessary and reflect cooperation between at least one compound in each
fraction. Identification of cuticular lipids shows that hydrocarbons were dominant (77%). Non-hydrocarbon compounds were mainly
represented by 15-nonacosanone (18% of the total lipid extract). This ketone is rare in insect cuticle lipids and is thought
to originate from the cabbage epicuticle where it is dominant with n-C29 and 14- and 15-nonacosanol also found among the cuticular lipids of the host caterpillar. 相似文献
13.
The experiments were undertaken to measure, for the first time, cardiac output in yellowtail (Seriola quinqueradiata) during exposure to a harmful red tide flagellate (Chattonella marina). The responses were compared with those during exposure to environmental hypoxia to evaluate the significance of the drop of arterial oxygen partial pressure (PaO2) in the fish-kill mechanisms by C. marina. PaO2 immediately decreased, whereas heart rate (HR) was maintained until shortly before death during exposure to C. marina. Suffocation developing during the exposure resulted from a decrease in blood oxygen content, but not from lowered blood flow to the tissue. Although exposure to both C. marina and hypoxia immediately decreased PaO2, arterial oxygen content (CaO2) and pH (pHa) were significantly lower, whereas HR and cardiac output (&Qdot;) remained significantly higher, for the C. marina-exposed fish than for hypoxia-exposed fish. Although the drop in PaO2 appears to play a pivotal role in the mechanisms of fish death by C. marina, other physiological response(s) should also be considered. 相似文献
14.
Rachel Vallender Vicki L. Friesen Raleigh J. Robertson 《Behavioral ecology and sociobiology》2007,61(12):1797-1807
We examined two components of reproduction in a population of golden-winged warblers in the initial stages of hybridization
with blue-winged warblers. First, we used genetic analyses of mate choice to determine whether copulations outside the social
pairbond (extra-pair copulations; EPCs) occur in these species and their hybrids. Second, we compared several aspects of reproduction
(pairing success, clutch size, hatching success, fledging success, and loss of paternity) in nests raised by phenotypic golden-winged
warblers to those raised by hybrid individuals. Together, these data provide us with the first quantitative analysis of reproduction
within this hybrid system. Our data suggest several reasons why the level of hybridization between these species is likely
being underestimated. First, many birds in our population showed only subtle phenotypic signs of introgression indicating
that hybrid status can only be determined by close examination. Second, high rates of extra-pair paternity indicate that we
cannot base our estimates of hybridization on pairbond data alone. More than 30% of nestlings were the result of EPCs, occurring
in 55% of all nests. Third, there was no difference in the number of hybrid or “pure” golden-winged warbler males chosen as
social mates, relative to their abundance. Indeed, based on several components of nesting success, it appears as though hybrids
are having as great realized reproductive success as are phenotypic golden-winged warblers in our population. Accordingly,
we argue that hybrid reproductive success and extra-pair fertilizations are likely playing a major role in the ongoing hybridization
between blue-winged and golden-winged warblers. Studies such as this one are important to our understanding of the process
and implications of hybridization, and findings may be applicable to other hybrid zones. 相似文献
15.
Johannes Stökl Robert Twele Dirk H. Erdmann Wittko Francke Manfred Ayasse 《Chemoecology》2007,17(4):231-233
Summary.
Ophrys flowers mimic the female produced sex pheromone of their pollinator species to attract males for pollination. The males try
to copulate with the putative female and thereby pollinate the flower. Using electrophysiological and chemical analyses, floral
volatiles released by O. iricolor as well as the female sex pheromone of its pollinator species, Andrena morio are investigated. Overall, 38 peaks comprising 41 chemical compounds, were found to release reactions in the antennae of
male A. morio bees. Analyses using coupled gas chromatography-mass spectrometry revealed the presence of alkanes and alkenes with 20 to
29 carbon atoms, aldehydes (C9 to C24) and two esters. Almost all of those compounds were found in similar proportions in
both, the floral extracts of O. iricolor and cuticle surface extracts of A. morio females. The pattern of biologically active volatiles described here is very similar to that used by other Ophrys species pollinated by Andrena males. 相似文献
16.
Piyamas Nanork Siriwat Wongsiri Benjamin P. Oldroyd 《Behavioral ecology and sociobiology》2007,61(10):1509-1514
Honey bee workers are able to distinguish queen-laid eggs from worker-laid eggs, and remove (‘police’) worker-laid eggs. The
cue that police workers use is as yet unidentified but is likely to be a chemical signal. This signal benefits queens for
it ensures their reproductive monopoly. It also benefits collective workers because it allows them to raise more closely related
queen-laid males than the less-related sons of half sisters. Because both parties benefit from the egg-marking signal, it
should be stable over evolutionary time. We show that Apis mellifera workers can distinguish queen-laid from worker-laid eggs of the dwarf honey bee A. florea, a phylogenetically distant species that diverged from the A. mellifera lineage 6–10 mya. However, A. mellifera workers are unable to distinguish worker-laid eggs of A. cerana, a much more recent divergence (2–3 mya). The apparent change in the egg-marking signal used by A. cerana may be associated with the high rates of ovary activation in this species. 相似文献
17.
Structure and complexity of the substrate are important habitat characteristics for benthic epifauna. The specific growth and mortality rates and inducible defence characters on medium-sized blue mussels (Mytilus edulis L.) exposed to shore crabs (Carcinus maenas L.) were examined on three different substrate types in combined field and laboratory experiments. The experiments showed that complexity of the substrate increased blue mussel survival significantly, through a decrease in predation pressure. However, increased intraspecific competition for food on the complex substrate resulted in significantly lower growth rates of the mussels. Inducible defence characters were also influenced by substrate type. Blue mussels were more affected by predators on the structurally simple substrate, where they developed thicker shells and a larger posterior adductor muscle. 相似文献
18.
Merrill A. Peterson Susanne Dobler Erica L. Larson Danielle Juárez Tim Schlarbaum Kirsten J. Monsen Wittko Francke 《Chemoecology》2007,17(2):87-96
Summary. Chemical signals frequently underlie sexual isolation between insect species. Our understanding of the evolutionary forces
influencing these signaling systems is known for very few systems, challenging both our efforts to understand insect speciation,
and our ability to predict long-term changes in the chemical communication systems of insects. Thus, we are in need of more
systems in which both the chemical signals causing sexual isolation and the evolutionary forces driving sexual isolation are
understood. Sexual isolation in the hybrid zone between Chrysochus cobaltinus and C. auratus has apparently increased in response to natural selection against hybridisation (i.e. reinforcement). Previous experiments
suggested that this isolation was due, at least in part, to male preferences for conspecific females. Here, we confirm this
role of male choice, and document that male mate choice in this system is influenced by cuticular hydrocarbon (CHC) profiles.
Specifically, male C. cobaltinus responses to control cadavers and conspecific female cadavers painted with different cuticular hexane extracts, together
with analyses of the composition of those extracts, revealed that male mate choice is governed by CHC profiles. Multivariate
analyses of GC profiles demonstrated that those profiles are indeed both sex- and species-specific. Although GC-MS enabled
identification and quantification of the specific cuticular hydrocarbons, we have not yet determined which individual compounds
govern mate choice. Having established that CHCs influence sexual isolation in this system, we can now assess the evolutionary
lability of these cues, which will inform both our understanding of speciation, and of the conditions under which the chemical
signaling systems that influence mate choice in insects can evolve. 相似文献
19.
Gabriele Gerlach Andrea Hodgins-Davis Bradley MacDonald Rebecca C. Hannah 《Behavioral ecology and sociobiology》2007,61(11):1765-1770
Zebrafish (Danio rerio) larvae prefer the olfactory cues of kin to non-kin. We examined the potential benefits of kin preference by comparing growth
rate, shoaling, and aggressive behavior in juvenile zebrafish housed in groups of either familiar kin or unfamiliar non-kin.
Over an observation period of 5 days, the animals grew 33% more in kin groups; however, neither shoaling nor the frequency
of aggressive interactions was different in groups of related versus unrelated individuals. Shoaling behavior increased with
increasing observation time and increasing age, while aggressive behavior remained the same. We conclude that associating
with kin probably creates a less stressful environment that allows for higher growth rates, which can lead to higher direct
fitness based on increased survival and earlier reproduction. Kin recognition leading to kin-structured groups may therefore
be under positive selection. 相似文献
20.
A. Machias S. Somarakis N. Papadroulakis M.-T. Spedicato M. Suquet G. Lembo P. Divanach 《Marine Biology》2003,142(1):45-52
The wreckfish (Polyprion americanus) is a panoceanic, long-lived, deep-water demersal species, characterized by an extended pelagic juvenile phase associated with floating objects. In the present study morphometric data from 435 specimens collected from Greece (Crete), Italy (Ionian Sea) and the Atlantic coast of France from September 1999 to March 2001 were analyzed to estimate the settlement size of the species and associated changes in morphology. The fishery sample included specimens from both the pelagic and the demersal stage. Length-at-settlement (TL50) and 95% confidence intervals were estimated by fitting a logistic function. Eleven morphometric characters were analyzed, and the existing inflection points, reflecting alterations in body shape, were defined: (1) iteratively, as the transition point, splitting the data set into two groups, for which the reduced major axis functions, between a character and total length, of the successive groups best fit (minimum sum of squares of residuals) the combined data set and (2) where the second derivative of the fitted third-order polynomial functions to morphometric ratios equaled zero. The main size range within which wreckfish settled was 56-65 cm, and the means of the inflection points defined by the two methods were 61 and 64 cm. These results indicate changes in functional morphology associated with settlement. The monitoring of wreckfish juveniles caught in the wild and kept individually in captivity showed changes in growth and food intake at approximately the estimated settlement length and suggested that temperature was the most likely factor triggering settlement. 相似文献