Integrative and Comparative Biology 

About: Integrative and Comparative Biology is an academic journal published by Oxford University Press. The journal publishes majorly in the area(s): Population & Biology. It has an ISSN identifier of 1540-7063. Over the lifetime, 5371 publications have been published receiving 272822 citations. The journal is also known as: Integrative and comparative biology & Integr. Comp. Biol..

Parent-Offspring Conflict

Abstract: When parent-offspring relations in sexually reproducing species are viewed from the standpoint of the offspring as well as the parent, conflict is seen to be an expected feature of such relations. In particular, parent and offspring are expected to disagree over how long the period of parental investment should last, over the amount of parental investment that should be given, and over the altruistic and egoistic tendencies of the offspring as these tendencies affect other relatives. In addition, under certain conditions parents and offspring are expected to disagree over the preferred sex of the potential offspring. In general, parent-offspring conflict is expected to increase during the period of parental care, and offspring are expected to employ psychological weapons in order to compete with their parents. Detailed data on mother-offspring relations in mammals are consistent with the arguments presented. Conflict in some species, including the human species, is expected to extend to the adult reproductive role of the offspring: under certain conditions parents are expected to attempt to mold an offspring, against its better interests, into a permanent nonreproductive.

Stress in Fishes: A Diversity of Responses with Particular Reference to Changes in Circulating Corticosteroids

Abstract: Physical, chemical and perceived stressors can all evoke non-specific responses in fish, which are considered adaptive to enable the fish to cope with the disturbance and maintain its homeostatic state. If the stressor is overly severe or long-lasting to the point that the fish is not capable of regaining homeostasis, then the responses themselves may become maladaptive and threaten the fish's health and well-being. Physiological responses to stress are grouped as primary, which include endocrine changes such as in measurable levels of circulating catecholamines and corticosteroids, and secondary, which include changes in features related to metabolism, hydromineral balance, and cardiovascular, respiratory and immune functions. In some instances, the endocrine responses are directly responsible for these secondary responses resulting in changes in concentration of blood constituents, including metabolites and major ions, and, at the cellular level, the expression of heat-shock or stress proteins. Tertiary or whole-animal changes in performance, such as in growth, disease resistance and behavior, can result from the primary and secondary responses and possibly affect survivorship.Fishes display a wide variation in their physiological responses to stress, which is clearly evident in the plasma corticosteroid changes, chiefly cortisol in actinopterygian fishes, that occur following a stressful event. The characteristic elevation in circulating cortisol during the first hour after an acute disturbance can vary by more than two orders of magnitude among species and genetic history appears to account for much of this interspecific variation. An appreciation of the factors that affect the magnitude, duration and recovery of cortisol and other physiological changes caused by stress in fishes is important for proper interpretation of experimental data and design of effective biological monitoring programs.

Morphology, Performance and Fitness

Abstract: Synopsis. Selection can be measured in natural populations by the changes it causes in the means, variances and covariances of phenotypic characters. Furthermore the force of selection can be measured in conventional statistical terms that also play a key role in theoreticai equations for evolutionary change. The problem of measuring selection on morphological traits is simplified by breaking the task into two parts: measurement of the effects of morphological variation on performance and measurement of the effects of performance on fitness. The first part can be pursued in the laboratory but the second part is best accomplished in the field. The approach is illustrated with a hypothetical analysis of selection acting on the complex trophic morphology of snakes.

Integrating Thermal Physiology and Ecology of Ectotherms: A Discussion of Approaches

Abstract: synopsis. An understanding of interactions between the thermal physiology and ecology of ectotherms remains elusive, partly because information on the relative performance of whole-animal physiological systems at ecologically relevant body temperatures is limited. After discussing physiological systems that have direct links to ecology (e.g., growth, locomotor ability), we review analytical methods of describing and comparing certain as? pects of performance (including optimal temperature range, thermal performance breadth), apply these techniques in an example on the thermal sensitivity of locomotion in frogs, and evaluate potential applications.

Cellular and dynamic aspects of oocyte growth in teleosts

Abstract: SYNOPSIS. Four principal stages of oocyte growth are recognized among teleosts. During gonadotropin-independent primary growth, multiple nucleoli form as well as a Balbiani body which eventually disperses throughout the ooplasm. The first gonadotropin-dependent stage involves the formation of yolk vesicles, the precursors to the cortical alveoli. True vitellogenesis follows during which vitellogenin is sequestered from the maternal blood and packaged into yolk granules or spheres. The latter generally fuse centripetally at some time during oocyte growth to give a continuous fluid phase surrounded by a peripheral layer of cytoplasm containing the cortical alveoli. Maturation represents the final stage and is accompanied in many teleosts by water uptake; among marine teleosts with pelagic eggs, most of the final egg volume may be achieved by this process. Ovaries may be synchronous, asynchronous, or group-synchronous. Among the latter, a clutch of oocytes may be recruited from an asynchronous population of earlier stages into any of the subsequent stages. In teleosts which spawn repeatedly, recruitment of new clutches can usually be associated with the transition of a previously recruited clutch from one stage to the next. Teleosts thus offer examples of virtually every conceivable type of ovarian physiology and provide a wealth of experimental material for exploring the cellular and hormonal mechanisms which regulate oocyte recruitment and growth throughout ovarian recrudescence.