نتایج جستجو برای: gills
تعداد نتایج: 3262 فیلتر نتایج به سال:
Osmoregulating decapods such as the Mediterranean green crab Carcinus aestuarii possess two groups of spatially segregated gills: anterior gills serve mainly respiratory purposes, while posterior gills contain osmoregulatory structures. The co-existence of similar tissues serving different functions allows the study of differential adaptation, in terms of free radical metabolism, upon salinity ...
Pharyngeal gills are a fundamental feature of the vertebrate body plan [1]. However, the evolutionary history of vertebrate gills has been the subject of a long-standing controversy [2-8]. It is thought that gills evolved independently in cyclostomes (jawless vertebrates-lampreys and hagfish) and gnathostomes (jawed vertebrates-cartilaginous and bony fishes), based on their distinct embryonic o...
Plasticity in hatching timing allows embryos to balance egg- and larval-stage risks, and depends on the ability of hatching-competent embryos to continue developing in the egg. Hypoxia can slow development, kill embryos and induce premature hatching. For terrestrial eggs of red-eyed treefrogs, the embryonic period can extend approximately 50% longer than development to hatching competence, and ...
background: the increasing use of nanomaterials and nanoproducts has increased the possibility of contamination of the environment, which may have adverse effects on different organisms. the aim of this study was to evaluate the effects of silver nanoparticles on histopathology and gill ultrastructure of zebrafish (danio rerio) under laboratory conditions. methods: zebrafish were exposed to fou...
Calcitonin is an important physiological regulator of salmon gills. Although the calcitonin receptor was found in salmon gills, the critical question concerning the source of the hormone remained unanswered. In this communication, evidence is presented for expression of calcitonin mRNA and its encoded peptide in gills of the pink salmon, Oncorhynchus gorbuscha. The expression of calcitonin gene...
A leading hypothesis for the origin of insect wings is that they evolved from thoracic gills that were serial homologues of the abdominal gills present in fossil pterygotes and in the nymphs of some modern mayflies, damselflies and stoneflies. Co-occurrence of thoracic wings and abdominal gills is the primitive condition for fossil pterygote insects, whereas the winged stage of modern insects a...
Some kinetic properties of gill Na(+),K(+)-ATPase of the estuarine crab, Chasmagnathus granulata, and its involvement in osmotic adaptation were analyzed. Results suggest the presence of different Na(+),K(+)-ATPase isoforms in anterior and posterior gills. They have different affinities for Na(+), but similar affinity values for K(+), Mg(2+), ATP and similar enzymatic profiles as a function of ...
Na(+)/H(+) exchangers (NHE) are a family of ion exchangers with diverse functions that are well defined in mammals. NHE-1 is expressed in the plasma membrane of most mammalian cells where it regulates intracellular pH, and usually in the basolateral membrane of epithelial cells. It has also been detected in teleost gills where it may participate in systemic pH regulation. NHE-3 is usually expre...
The gills of Ichthyophis bannanicus have yet to be investigated. This paper describes the external morphological features of the gills of mature I. bannanicus embryos exhibiting three pairs of gills on their neck region. Each gill is composed of an axis and filaments. In newly released embryos, the filaments and the axis form at approximately 90° relative to each other; eventually, this angle d...
Levels of Zn, Cu, Cd, As, and Pb in the kidney, Liver, Gills and Heart of African cat fish (Clarias gariepinus) from the Ogun River in Ogun State located close to six major industries in the South Western part of Nigeria, were determined using Bulk Scientific Atomic Absorption Spectrophotometer. Fishes were also collected from Government owned fish farm in Agodi, Ibadan which was considered a r...
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