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21.
Aspects of the reproductive biology of the concha wrasse, Nelabrichthys ornatus, at Tristan da Cunha 总被引:1,自引:0,他引:1
Synopsis The reproductive biology of the concha wrasse, Nelabrichthys ornatus, at Tristan da Cunha in the South Atlantic Ocean is described. Histological evidence shows that the species is a monandric protogynous hermaphrodite. N. ornatus displays full permanent sexual dichromatism with all males occurring in the upper size classes of the population. Size specific habitat preference is described. Aspects of the mating system of the species resemble a lek although the possibility of mating site selection by females is not discounted. Spawning groups have a sex ratio of between 4 and 7 females per male. 相似文献
22.
Klaus Zuberbühler Lorenz Gygax Nerida Harley Hans Kummer 《Primates; journal of primatology》1996,37(1):1-12
In a captive group of long-tailed macaques, tool-using behavior by a single competent individual had a significant effect on the synchronous manipulative behavior of naïve animals. Group members engaged in manipulations on the same object class more frequently during times when the model was working than when it was not. The form of their behavior, however, in no way resembled the technique used by the model. All three animals that later became successful tool users were among the few subjects that exhibited a significant increase in manipulations on the same object class while the model was working. Possible causal relationships between this stimulus enhancement and the transmission of the new behavior to other group members are analyzed and discussed. 相似文献
23.
It has been suggested by some that the acquisition of symbolic capital in terms of honor, prestige, and power translates into an accumulation of material capital in terms of tangible belongings, and that on the basis of these goods high reproductive success may be achieved. However, data on completed fertility rates over more than one generation in so-called traditional societies have been rare. Ethnographic and demographic data presented here on the pastoral Bakkarwal of northern India largely corroborate the hypothesis concerning the interdependence between the attainment of various cultural goals and differential reproduction rates and indicate that the numbers of (especially male) surviving offspring and siblings are crucial to a man’s position in society. 相似文献
24.
Summary 1. The amygdaloid complex is a key structure in mechanisms of fear and anxiety. Expression of the immediate-early gene c-fos has been reported in the central nucleus of the amygdala following various stressors, but the functional role of this phenomenon has remained unknown.2. c-fos expression was observed in the central nucleus when rats were subjected to a pharmacologically validated animal model of anxiety, the Vogel conflict test, but not after mere exposure to the test apparatus. Bilateral amygdala injection of a 15-mer phosphorothioate c-fos antisense oligodeoxynucleotide prior to testing blocked conflict-induced c-fos expression and had behavioral effects similar to those of established antianxiety drugs.3. Separate experiments determined that antisense treatment did not affect conflict behavior by acting on shock thresholds or drinking motivation.4. These findings provide evidence that neuronal activation and c-fos induction in the amygdala may be of importance for mechanisms of fear and anxiety. 相似文献
25.
Raphael Chalmeau 《Primates; journal of primatology》1994,35(3):385-392
The aim of this study was to assess the ability of chimpanzees (Pan troglodytes) to cooperate in an instrumental task. A specially constructed fruit distributor was presented to a group of six captive
chimpanzees. A cooperative response required two chimpanzees: both had to pull a handle simultaneously to make a fruit fall
into the cage. The dominant male of the group and an infant produced most of the operant responses, and the male got nearly
all the fruits. Other conspecifics avoided the dominant male at the apparatus. Social influences appear to limit the possibility
of co-operation between individuals because a certain level of interindividual tolerance is required. The results revealed
a significant increase in the number of pulls each time both chimpanzees were together at the apparatus. Operant chimpanzees
learn to coordinate their actions in time and space. 相似文献
26.
27.
Kenji Kawanaka 《Primates; journal of primatology》1993,34(3):255-270
Proximity partner choice by male chimpanzees of various age classes was analyzed in relation to their spatial positioning.
Field work was carried out twice at the Mahale Mountains National Park, Tanzania. Proximity data were recorded at 3 and 10m
from the focal animal. The data for the proximity between the focal male and other individuals allowed the males to be classified
into two categories according to both criteria: early adolescence to young adult, and prime to old age. Between the males,
the 3m proximity data permitted a classification into two categories as above, but those for 10m did not. These two spatial
distances thus probably have different meanings for the males. The numbers of male proximity partners and proximity with the
alpha male also allowed the males to be classified into two categories: early and late adolescence, and young adult to old
age. Together, the above results support the classification of males into three age-graded categories: (1) early and late
adolescence, (2) young adult, and (3) prime to old age. This does not arise because the males of each category form an age
group. Prime or older males are most frequently in proximity, while their juniors consistently attempt to approach them. However,
even prime or older males are not equally in proximity with one another. Their proximity partners change as time passes. Probably
recognizing such changes, they form coalitions or are in rivalry. The sexual interest of adolescent males is probably a factor
stimulating them to separate from their mothers, and to approach older males. Young adult males, even though physically mature,
do not have equal proximity relations with older males. They are not yet sufficiently qualified to join the coalitions formed
by their seniors. 相似文献
28.
Troy A. Baird 《Environmental Biology of Fishes》1993,38(4):393-397
Synopsis The bar jack,Caranx Tuber, was commonly observed to follow individual puddingwife wrasses,Halichoeres radiatus, that were foraging on the substrate. Individuals of both species actively pursued the other to maintain these heterospecific foraging teams, were sometimes attracted to feeding acts initiated by team partners, and the foraging rates of teamed jacks and wrasses were positively correlated. Pilfering of food items was rare, suggesting little, if any, competition cost of this foraging association. The ratio of bites to search in teamed jacks was over three times that when solitary, and jacks were sometimes aggressive to conspecifics attempting to join their team, suggesting that the association is beneficial to the jacks. Both bite and search rates were higher in puddingwifes when teamed with a jack, indicating that the association also benefits the wrasses. Benefits to puddingwifes may be derived directly from attendants because wrasses were sometimes attracted to jack foraging acts. However, increased foraging in wrasses may also be a consequence of heightened motivation to feed owing to heterospecific social facilitation. 相似文献
29.
《L'Anthropologie》2023,127(1):103101
The Mesolithic is a fascinating period, where ancient traditions are tilting towards a new paradigm. Many changes can be recognised without being able to establish a real split with the Palaeolithic. Far from being just a bridge towards the Neolithic, the Mesolithic is truly a new and stable metaphysical structure. In our article, we are interested in the structural mechanisms by which Palaeolithic metaphysics slides towards the Mesolithic, where the individual occupies a central role. 相似文献
30.
This study investigates the effects of partial exhalation to feelings of anxiety. Thirty five volunteer subjects (14 male, 21 female, mean age 40.6) were first trained in slow diaphragmatic breathing (SDB). Then subjects rated their anxiety levels on a scale from 1 (none) to 5 (extreme) in sequential conditions of SDB, 70% subjective exhalation, and SDB. During the 70% subjective exhalation phase, subjects were instructed to breathe and limit their exhalation to 70% of the inhaled volume during each consecutive breath. The 70% subjective condition significantly (P<.0005) increased=" subjects'=" anxiety=" levels=" as=" compared=" to=" the=" initial=" sdb=" baseline,=" while=" a=" return=" to=" sdb=" significantly=" reduced=" the=" anxiety=" levels.=" the=" 70%=" approach=" appears=" useful=" in=" demonstrating=" to=" the=" client=" that=" possible=" changes=" in=" breathing=" patterns=" can=" affect=">We gratefully acknowledge the assistance of Richard Steiner, Ph.D. for his comments and help with the statistical analysis in this article. The preliminary findings of this article were presented at the Twenty-first Annual Meeting of the Association for Applied Psychophysiology and Biofeedback. 相似文献