caa a22 4500 477096867 CHVBK 20180405111530.0 cr unu---uuuuu 170330e19960601xx s 000 0 eng 10.1007/BF01995827 doi (NATIONALLICENCE)springer-10.1007/BF01995827 A comparative allometric study of the morphometry of the gills of an alkalinity adapted cichlid fish, Oreochromis alcalicus grahami , of Lake Magadi, Kenya [Elektronische Daten] [J. Maina, S. Kisia, C. Wood, A. Narahara, H. Bergman, P. Laurent, P. Walsh] A morphometric analysis of the gills ofOreochromis alcalicus grahami has been carried out on specimens from ecologically distinct lagoons and a water-holding tank of Lake Magadi, a highly alkaline salt lake situated in a volcanically active region of the southern part of the Great Rift Valley in Kenya. The data were compared with those fromOreochromis niloticus, a close relative that lives in fresh water and with data from other fresh water and marine fish. Our primary goal was to identify the possible adaptive features which enable the fish to survive in an environment characterized by severely fluctuating levels of oxygen, a condition exacerbated by factors such as high temperature, alkalinity and osmolarity. The specimens ofO. a. grahami from the south-western lagoons of the lake had gills better adapted for gas exchange with a body mass specific diffusing capacity for oxygen which was about 2 times greater than that of the gills of the specimens from the fish spring lagoons and 2.5 times that of those from the water-holding tanks. Some parameters of the gills ofO. a. grahami, e.g. the gill filament length and number of gill filaments are significantly greater than those ofO. niloticus but the number of secondary lamellae, area of secondary lamellae and the diffusing capacity of the gills are similar in the two species. Compared with most other fish, the gills ofO. a. grahami appear to be particularly well adapted for gas exchange especially by having a thin water-blood barrier. Perhaps in no other extant fish have the gills had to be so exquisitely designed to meet environmental extremes and regulate complex and at times conflicting functions such as gas exchange, iono-regulation, acid-base balance and nitrogenous waste excretion as inO. a. grahami Kluwer Academic Publishers, 1996 Lake Magadi nationallicence lagoons nationallicence tilapia nationallicence alkalinity nationallicence gills nationallicence diffusion nationallicence respiration nationallicence Maina J. Department of Veterinary Anatomy, University of Nairobi, P.O. Box 30197, Nairobi, Kenya aut Kisia S. Department of Veterinary Anatomy, University of Nairobi, P.O. Box 30197, Nairobi, Kenya aut Wood C. Department of Biology, McMaster University, L8S 4K1, Hamilton, Ontario, Canada aut Narahara A. Department of Zoology and Physiology, University of Wyoming, 82071, Laramie, Wyoming, USA aut Bergman H. Department of Zoology and Physiology, University of Wyoming, 82071, Laramie, Wyoming, USA aut Laurent P. Laboratoire de Morphologie Fonctionnelle et Ultrastructurale des Adaptations Centre d'Ecologie et de Physiologie Energetique, CNRS, BP 20CR, F-67037, Strasbourg, Cedex, France aut Walsh P. Division of Marine Biology and Fisheries, Rosentiel School of Marine and Atmospheric Science, 33149, Miami, Florida, USA aut International Journal of Salt Lake Research Kluwer Academic Publishers 5/2(1996-06-01), 131-156 1037-0544 5:2<131 1996 5 10770 https://doi.org/10.1007/BF01995827 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF01995827 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Maina J. Department of Veterinary Anatomy, University of Nairobi, P.O. Box 30197, Nairobi, Kenya aut NATIONALLICENCE 700 1- Kisia S. Department of Veterinary Anatomy, University of Nairobi, P.O. Box 30197, Nairobi, Kenya aut NATIONALLICENCE 700 1- Wood C. Department of Biology, McMaster University, L8S 4K1, Hamilton, Ontario, Canada aut NATIONALLICENCE 700 1- Narahara A. Department of Zoology and Physiology, University of Wyoming, 82071, Laramie, Wyoming, USA aut NATIONALLICENCE 700 1- Bergman H. Department of Zoology and Physiology, University of Wyoming, 82071, Laramie, Wyoming, USA aut NATIONALLICENCE 700 1- Laurent P. Laboratoire de Morphologie Fonctionnelle et Ultrastructurale des Adaptations Centre d'Ecologie et de Physiologie Energetique, CNRS, BP 20CR, F-67037, Strasbourg, Cedex, France aut NATIONALLICENCE 700 1- Walsh P. Division of Marine Biology and Fisheries, Rosentiel School of Marine and Atmospheric Science, 33149, Miami, Florida, USA aut NATIONALLICENCE 773 0- International Journal of Salt Lake Research Kluwer Academic Publishers 5/2(1996-06-01), 131-156 1037-0544 5:2<131 1996 5 10770 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer