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1.
Prey of different quality can be distinguished by their effects on fitness parameters (e.g., survival, growth, development)
of the predator. This paper describes a series of experiments with wolf spiders, Schizocosa sp., designed to analyze the behavioral and physiological mechanisms by which these effects are brought about. Schizocosa responded to prey of inferior quality by developing an aversion. The number of prey encounters needed for the aversion to
develop depended on the prey type and the quality of alternative prey available. As expected, fewer low-quality prey were
accepted if prey of higher quality were available; however, acceptance was also reduced if alternative prey were of even lower
quality. An aversion disappeared within a few hours to about 1 day. Consumption by Schizocosa of even small amounts of some “toxic” prey species reduced growth by inhibiting feeding rate and impairing utilization of
food derived from prey of higher quality. These results have implications for understanding the interactions of generalist
predators in community food webs.
Received: 29 July 1998 / Accepted: 1 February 1999 相似文献
2.
Individual specialization and trophic adaptability of northern pike (Esox lucius): an isotope and dietary analysis 总被引:3,自引:0,他引:3
Catherine P. Beaudoin William M. Tonn Ellie E. Prepas Leonard I. Wassenaar 《Oecologia》1999,120(3):386-396
Northern pike (Esox lucius) are often considered to be specialist piscivores, but under some circumstances will continue to eat invertebrates as adults.
To examine effects of fish assemblage composition on the trophic ecology of pike, we combined stable isotope analysis (SIA)
of carbon and nitrogen and stomach content analysis (SCA) on pike from five lakes in northern Alberta, three of which contain
only pike (“pike-only”) and two that also contain yellow perch (Perca flavescens) or white sucker (Catostomus commersoni) (“pike-other”). Fish were more important as prey and empty stomachs, which often characterize piscivores, were significantly
more frequent in pike-other than in pike-only lakes. However, even though invertebrates were more important for pike in pike-only
lakes, SIA and SCA indicated that invertebrates were also an important component of pike diets in pike-other lakes. SIA and
SCA also revealed considerable intrapopulation variation in trophic ecology, with individuals in some populations differing
by as much as two trophic levels. Comparisons of stomach contents and isotope signatures of the same fish suggested that within
these variable populations, specialization on invertebrates or fish was a long-term trait of some individuals. SIA indicated
that trophic position increased and diets shifted to a greater importance of littoral prey as pike grew in pike-only lakes,
but not in lakes with other fish present. Trophic adaptability in northern pike is expressed at both the population level,
where the trophic ecology is sensitive to differences in prey regimes, and at the organismal level, in the form of intrapopulation
variation and individual specialization.
Received: 1 July 1998 / Accepted: 3 February 1999 相似文献
3.
We propose a simple experiment to study delocalization and extinction in inhomogeneous biological systems. The nonlinear
steady state for, say, a bacteria colony living on and near a patch of nutrient or favorable illumination (“oasis”) in the
presence of a drift term (“wind”) is computed. The bacteria, described by a simple generalization of the Fisher equation,
diffuse, divide A→A + A, die A→ 0, and annihilate A + A→ 0. At high wind velocities all bacteria are blown into an unfavorable region (“desert”), and the colony dies out. At low
velocity a steady state concentration survives near the oasis. In between these two regimes there is a critical velocity at
which bacteria first survive. If the “desert” supports a small nonzero population, this extinction transition is replaced
by a delocalization transition with increasing velocity. Predictions for the behavior as a function of wind velocity are made
for one and two dimensions.
Received: 3 August 1998 / Revised version: 17 July 1999 / Published online: 4 July 2000 相似文献
4.
Stomach contents of the landlocked dwarf ayu in Lake Biwa, Japan 总被引:1,自引:1,他引:0
5.
A new species Dolichopteryx minuscula is described on the basis of three specimens [49.4–59.6 mm in standard length (SL)] collected from the Indo-West Pacific.
The new species is characterized by pouchlike eyes with a small lens (lens diameter 2.2% SL), an adipose fin, the anal fin
base originating posterior to the dorsal fin base, and 16–17 (= 5–6 + 1 + 10–11) gill rakers. Total fecundity was relatively
low, only 658 ova being obtained from one specimen, despite the ovary being mature. Ovarian eggs were clearly subdivided into
“undeveloped” (0.1–0.7 mm diameter classes, n = 561) and “developed” (1.0–1.3 mm classes, n = 97) groups, based on their frequency distribution. Such relatively low fecundity and frequency distributions of ovarian
eggs suggest that Dolichopteryx species spawn iteratively during spawning season. 相似文献
6.
A new species, Dolichopteryx rostrata, is described on the basis of a single specimen (66.2 mm in standard length) collected west of the Hebrides Islands, eastern
North Atlantic Ocean. The new species is characterized by an elongate snout and head, small pouchlike eyes, an adipose fin,
short dorsal fin base, anal fin base originating under dorsal fin base, a clear longitudinal suborbital brownish band extending
forward from behind posterior margin of orbit to snout tip, and 41 (=26 + 15) vertebrae. Total fecundity is low; the ovarian
eggs number only 473, despite the ovary having developed ova. Ovarian eggs could be clearly subdivided into an “undeveloped
group” (0.1–0.7 mm diameter classes, n = 405) and a “developed group” (0.9–1.3 mm classes, n = 68), based on their frequency distribution.
Supplementary material to this paper is available in electronic format at http://dx.doi.org/10.1007/s10228-005-0306-2 相似文献
7.
Marc Holderied Carmi Korine Thorsten Moritz 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2011,197(5):425-433
Over 70% of the droppings of the gleaning bat Otonycteris hemprichii can contain scorpion fragments. Yet, some scorpions found in its desert habitat possess venom of the highest known toxicity,
rendering them a very dangerous prey. In this study, we describe how O. hemprichii catches and handles scorpions, quantify its flight and echolocation behaviour in the field, investigate what sensory modality
it uses to detect scorpions, and test whether it selects scorpions according to their size or toxicity. We confirmed that
O. hemprichi is a whispering bat (approx. 80 dB peSPL) with short, multi-harmonic calls. In a flight room we also confirmed that O. hemprichii detects scorpions by their walking noises. Amplitudes of such noises were measured and they reach the flying bat at or below
the level of echoes of the loess substrate. Bats dropped straight onto moving scorpions and were stung frequently even straight
in their face. Stings did not change the bats’ behaviour and caused no signs of poisoning. Scorpions were eaten including
poison gland and stinger. Bats showed no preference neither for any of the scorpion species nor their size suggesting they
are generalist predators with regard to scorpions. 相似文献
8.
D. D. Gaffin P. H. Brownell 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1997,181(3):301-307
The pectines of scorpions are ventral bilateral appendages supporting 104–105 chemosensory sensilla called pegs. Each peg contains 10–18 sensory neurons, some of which show ultrastructural evidence of
axo-axonic synapses with other sensory neurons in the same sensillum. In extracellular recordings from single-peg sensilla,
individual sensory units can be distinguished by impulse waveform and firing frequency. Cross-correlation analysis of impulse
activity showed that at least two of these units, types `A1' and `A2', are inhibited during the 100-ms period immediately
following activity of a third unit, type `B'. This interaction between sensory units in a single sensillum also occurs in
surgically isolated pectines, indicating that it does not involve efferent feedback from the central nervous system. Other
sensillar neurons appear to have excitatory interactions. Thus, in scorpion pectine, chemosensory information undergoes some
form of processing within individual sensilla prior to its relay to the CNS, making this an unusually accessible preparation
for study of first-order chemosensory processing events.
Accepted: 12 April 1997 相似文献
9.
Lourenço WR 《Comptes rendus biologies》2003,326(12):1149-1155
A new genus and species of humicolous buthid scorpion are described on the basis of a single specimen collected in French Guyana. New considerations on the taxonomy and morphology of some micro-buthoid humicolous scorpions are proposed, mainly based on the study by scanning electron microscopy of the peg-shaped sensillae of the pectines. 相似文献
10.
F. J. Gallego C. Benito 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,95(3):393-399
Aluminium (Al) tolerance in roots of two cultivars (“Ailés” and “JNK”) and two inbred lines (“Riodeva” and “Pool”) of rye
was studied using intact roots immersed in a nutrient solution at a controlled pH and temperature. Both the cultivars and
the inbred lines analysed showed high Al tolerance, this character being under multigenic control. The inbred line “Riodeva”
was sensitive (non-telerant) at a concentration of 150 μM, whereas the “Ailes” cultivar showed the highest level of Al tolerance
at this concentration. The segregation of aluminium-tolerance genes and several isozyme loci in different F1s, F2s and backcrosses between plants of “Ailés” and “Riodeva” were also studied. The segregation ratios obtained for aluminium
tolerance in the F2s analysed were 3 : 1 and 15 : 1 (tolerant : non-tolerant) while in backcrosses they were 1 : 1 and 3 : 1. These results indicated
that Al tolerance is controlled by, at least, two major dominant and independent loci in rye (Alt1 and Alt3). Linkage analyses carried out between Al-tolerance genes and several isozyme loci revealed that the Alt1 locus was linked to the aconitase-1 (Aco1), nicotinamide adenine dinucleotide dehydrogenase-2 (Ndh2), esterase-6 (Est6) and esterase-8 (Est8) loci, located on chromosome arm 6RL. The order obtained was Alt1-Aco1-Ndh2-Est6-Est8. The Alt3 locus was not linked to the Lap1, Aco1 and Ndh2 loci, located on chromosome arms, 6RS, 6RL and 6RL respectively. Therefore, the Alt3 locus is probably on a different chromosome.
Received: 18 March 1997 / Accepted: 21 March 1997 相似文献
11.
Interspecific variation in the escape responses of aphids: effect on risk of predation from foliar-foraging and ground-foraging predators 总被引:1,自引:0,他引:1
A series of laboratory experiments was conducted to determine the effect of interspecific differences on prey defensive behavior
on the susceptibility of two aphid species (Acyrthosiphon pisum and A. kondoi) to a ground-foraging predator, Harpalus pennsylvanicus, and a foliar-foraging predator, Coccinella septempunctata. These organisms are representative of a biologically and economically important predator/prey system in alfalfa. The primary
defensive behavior of both aphid species toward C. septempunctata was to “drop” from the plant. Both aphid species were significantly more likely to drop from the plant in the presence of
C. septempunctata. However, when C. septempunctata was present, a significantly lower proportion of A. kondoi individuals dropped (0.42 ± 0.07) compared to A. pisum (0.73 ± 0.08). As a result of their lower propensity to drop from the plant A. kondoi individuals are significantly more likely to be consumed by C. septempunctata. Conversely, the higher propensity of A. pisum individuals to drop increased their susceptibility to ground-foraging predators. When A. pisum was the prey species, ground-foraging predators made a significant contribution to overall aphid suppression and there was
a significant synergistic interaction between ground and foliar-foraging predators. When A. kondoi was the prey there was no interaction between the predator species. As either a cause or consequence of its higher propensity
to drop, A. pisum seems to be more adapted for survival and dispersal off the plant. In comparison to A. kondoi individuals, A. pisum individuals relocate plants more quickly (63 ± 41 s vs. 164 ± 39 s), disperse farther (18 ± 1.7 cm vs. 13 ± 0.66 cm), and
survive longer (37 ± 2.0 h vs. 25 ± 2.0) off the plant. This study demonstrates the importance of prey defensive behavior
in determining the susceptibility of a prey species to a multiple-predator complex.
Received: 24 February 1997 / Accepted:17 December 1997 相似文献
12.
The adult feeding behavior of Liriomyza huidobrensis and L. trifolii was studied in beans of the variety “Catarino.” The insects
were placed on a bean leaf and its behavior observed and recorded on DVD for a period of 30 min. An ethogram was constructed
based on the different behavior parameters that were identified. The time that each species used in each behavior parameter
was registered and compared between the two species. When placed in the arena the two species behaved in a similar manner,
although some differences were observed. The adaptation of the leafminers species to the “Catarino” bean variety under these
experimental conditions and the possibility to use some behavioral parameters as indicators of the preference of these insects
in relation to the host plant are discussed. 相似文献
13.
P. J. Fonseca A. V. Popov 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1997,180(4):417-427
1. Laser vibrometry and acoustic measurements were used to study the biophysics of directional hearing in males and females
of a cicada, in which most of the male tympanum is covered by thick, water filled tissue “pads”. 2. In females, the tympanal
vibrations are very dependent on the direction of sound incidence in the entire frequency range 1–20 kHz, and especially at
the main frequencies of the calling song (3–7 kHz). At frequencies up to 10 kHz, the directionality disappears if the contralateral
tympanum, metathoracic spiracle, and folded membrane are blocked with Vaseline. This suggests some pressure-difference receiver
properties in the ear. 3. In males, the tympanal vibrations depend on the direction of sound incidence only within narrow
frequency bands (around 1.8 kHz and at 6–7 kHz). At frequencies above 10–12 kHz, the directionality appears to be determined
by diffraction, and the ear seems to work as a pressure receiver. The peak in directionality at 6–7 kHz disappears when the
contralateral timbal, but not the tympanum, is covered. Covering the thin ventral abdominal wall causes the peak around 1.8 kHz
to disappear. 4. Most observed tympanal directionalities, except around 1.8 kHz in males, are well predicted from measured
transmissions of sound through the body and measured values of sound amplitude and phase at the ears at various directions
of sound incidence.
Accepted: 18 October 1996 相似文献
14.
The genetic diversity and genetic relatedness of mei (Prunus mume; 2n = 16) were studied using amplified fragment length polymorphism (AFLP) markers. Eight EcoRI–PstI AFLP primer combinations were applied to 121 distinct genotypes of mei cultivars and related species. A total of 508 AFLP
product bands were produced, of which 382 were polymorphic. The unweighted pair group method with arithmetic averages analysis
was carried out based on these AFLP markers. From this analysis, “Qugeng Mei,” “Yan Mei,” “Chaodou Mei,” and mei cultivars
were seen to share the same P. mume genetic stem. The AFLP data were able to clearly discriminate P. mume from other species in the genus Prunus, with P. armeniaca aligning as its closest related species. Two major groups and nine subgroups of mei flower were identified, and there was
a strong coincidence of these AFLP-based groupings with the respective morphological characters of the accessions. The genetic
diversity of mei accessions was greatest in the Yunnan Province and decreased toward Eastern China and Japan, so supporting
the hypothesis that the southwest of China represents the genetic diversity center of the species. 相似文献
15.
We studied the predatory behavior of seven species of the genusLeptogenys from Mexico and Cameroon. The ants of this genus are armed with long, thin, curved mandibles articulated at the extreme corners
of the anterior margin of the head, permitting them easily to seize oniscoid isopods, the obligate or the principal prey of
mostLeptogenys species. Workers hunt these prey, which are able to roll themselves up, solitarily. Foraging behavior comprises sequences
of up to eight activities. The prey can be seized by the body (rolled up or not), or alternatively by the edge of the shell,
then turned over and stung on the ventral face. A relationship between the mandible size of the workers and the handling method
permitted us to established that the phase “seizure by the edge of the shell” (compared to grasping the prey by the body)
was more frequent as the prey size increased or the mandible length of the workers decreased. The rate of prey escape followed
the same pattern. When a prey escaped, workers reacted by using a local searching or “reserve” behavior: they moved by increasing
both sinuosity and speed. Recruitment occurred mainly after a worker found a group of prey or a large prey.L. mexicana are attractive at a distance to the isopods Bathytropidae living in the same natural environment. As a consequence, prey
capture is possible without foraging for this species. 相似文献
16.
Amphipod (Gammarus minus) responses to predators and predator impact on amphipod density 总被引:1,自引:0,他引:1
David E. Wooster 《Oecologia》1998,115(1-2):253-259
Recent theoretical work suggests that predator impact on local prey density will be the result of interactions between prey
emigration responses to predators and predator consumption of prey. Whether prey increase or decrease their movement rates
in response to predators will greatly influence the impact that predators have on prey density. In stream systems the type
of predator, benthic versus water-column, is expected to influence whether prey increase or decrease their movement rates.
Experiments were conducted to examine the response of amphipods (Gammarus minus) to benthic and water-column predators and to examine the interplay between amphipod response to predators and predator consumption
of prey in determining prey density. Amphipods did not respond to nor were they consumed by the benthic predator. Thus, this
predator had no impact on amphipod density. In contrast, amphipods did respond to two species of water-column predators (the
predatory fish bluegills, Lepomis macrochirus, and striped shiners, Luxilus chrysocephalus) by decreasing their activity rates. This response led to similar positive effects on amphipod density at night by both species
of predatory fish. However, striped shiners did not consume many amphipods, suggesting their impact on the whole amphipod
“population” was zero. In contrast, bluegills consumed a significant number of amphipods, and thus had a negative impact on
the amphipod “population”. These results lend support to theoretical work which suggests that prey behavioral responses to
predators can mask the true impact that predators have on prey populations when experiments are conducted at small scales.
Received: 21 March 1997 / Accepted: 15 December 1997 相似文献
17.
Lourenço WR 《Comptes rendus biologies》2004,327(1):77-83
A new genus and species of humicolous microcharmid scorpion are described on the basis of a single specimen collected in the Ankarana Reserve, Madagascar. New considerations regarding the taxonomy and morphology of micro-buthoid Malagasy scorpions are proposed, based mainly on the study of the peg-shaped sensillae of the pectines by scanning electron microscopy. 相似文献
18.
The inheritance of resistance to Plum pox virus (PPV) has been studied in 1,178 apricot hybrids. Seven hundred and eighteen F1 hybrids, obtained from controlled crosses
between the susceptible Greek cultivar “Bebecou” and the resistant PPV cultivars of American origin (“Stark Early Orange,”
‘NJA2,” ‘Veecot,” “Sunglo,” “Harlayne,” and “Orangered”) were evaluated for resistance to the PPV-M (Marcus) strain, 8 years
after artificial inoculation. The inheritance of resistance to PPV has been additionally studied for the first time in a BC1 population of 95 apricot hybrids for four vegetative periods. Reaction of each hybrid to PPV-M was scored through visual
symptoms, indexing onto GF-305 and double-antibody sandwich enzyme-linked immunosorbent assay tests. Segregation within the
hybrids, determined by Chi-squared analysis, fits a 1:1 ratio (P ≤ 0.05) of the resistant vs susceptible, indicating that resistance to PPV is controlled by a single dominant gene locus
and that the above six resistant cultivars are heterozygous for the trait. Plants carrying this gene may initially develop
disease symptoms on leaves but eventually recover and no virus can be detected in leaves. Susceptible plants show similar
symptoms initially but remain symptomatic. Inheritance of resistance to PPV also has been studied in 365 F1 hybrids by crossing
the resistant cultivar “Stella” with the susceptible “Bebecou” and the resistant cultivars “Sunglo” and “NJA2,” for 8 years
after inoculation. The segregation ratio was 1:0 (resistant/susceptible) suggesting that “Stella” is homozygous for the resistance
trait. The purpose of this work was the enhancement of the knowledge of inheritance of resistance to PPV for the selection
of new cultivars. 相似文献
19.
Philip Brownell Roger D. Farley 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1979,131(1):23-30
Summary The scorpionParuroctonus mesaensis locates prey by orienting to substrate vibrations produced by movements of the prey in sand. At the end of each walking leg of this scorpion there are two sense organs, the basitarsal compound slit sensillum and tarsal sensory hairs (Figs. 1, 3) that are excited by substrate vibrations conducted through sand. The slit sensilla appear to be most sensitive to surface (Rayleigh) waves while the tarsal sensory hairs respond best to compressional waves (Fig. 7). Both mechanoreceptors were activated by nearby disturbances of the substrate (Fig. 6) but only the slit sensilla responded to insects moving more than 15 cm away. Both receptors are highly sensitive to small amplitude (less than 10 Å) mechanical stimuli applied to the tarsus (Fig. 5).Behavioral studies of scorpions with ablated sense organs (Fig. 2) indicate that the basitarsal compound slit sensilla are necessary for determining vibration source direction.Abbreviation
BCSS
basitarsal compound slit sensillum (a)
Supported by PHS Environmental Science and Regents Intern Fellowships (PB), and by intramural research funds from the University of California (RDF) 相似文献
20.
ROGER D. FARLEY 《Invertebrate reproduction & development.》2013,57(2-3):193-208
Summary The scanning electron microscope was used to study changes in the ventral mesosoma of the vaejovid scorpion, Paruroctonus mesaensis. Observations are compared with those from scorpion fossils. The oldest fossils are from the Silurian period; migration from water to land occurred in the Carboniferous and Permian periods. All recent scorpions are terrestrial with four pairs of booklungs and spiracles in mesosomal sternites. Ancient eurypterids and scorpions had flap-like abdominal plates attached to the ventral surface of five mesosomal segments. The abdominal plates were apparently an aquatic adaptation, and authors have described possible gill tissue in the chamber above. In scorpion embryos, rectangular (holostem) plate-like structures precede the formation of sternites in the ventral mesosoma. Transverse folds were seen in the space above the abdominal plates. The lack of elaborate gill-like structures here supports an earlier hypothesis that aquatic scorpions had other mesosomal respiratory sites (e.g., pectines), resulting in less reliance on respiratory tissues above the abdominal plates. Spiracles initially appear as round or ovoid patterns in the epidermis at the latero-posterior margins of the ventral plates. The booklung spiracles are positioned farther anterior in sternites, but the developmental sequence for this transition is still unclear and may occur later than the stages of this study. The abdominal plates lengthen and enlarge laterally and/or epidermis is added at the lateral edges so that broad, overlapping sternites eventually cover the ventral surface of the mesosoma. 相似文献