The Breeding Season of the Multimammate Mouse Praomys (Mastomys) Natalensis (A. Smith) in the Transvaal Highveld |
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| Authors: | C G Coetzee |
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| Institution: | Medical Ecology Centre, State Dept. of Health, Johannesburg |
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| Abstract: | Certain aquatic Oligochaeta live successfully in organic-polluted waters while others cannot tolerate such conditions. Tubifex tempUtoni Southern and Llmnodrttus hoffmeisteri (Clap.), two non-gilled species, are compared to Branchiura sowerbyi (Beddard) and Dero nivea (Aiyer), two gilled species, concerning their haemoglobin concentration, the influence of low oxygen availability on the respiration rate and their reactions in an oxygen gradient. In contrast with L. hoffmeisteri and T. templetoni where a very narrow range of respiration dependency (pO2, 0-12 mm Hg) is found, B. sowerbyi and D. nivea have a level of respiratory dependence from pO2, 0-131 mm Hg. Haemoglobin concentrations are 6,238 - and 6,452 g/100 cm2 blood in L. hoffmeisteri and T. templetoni and 3,011 and 1,611 g/100 cm2 in B. sowerbyi and D. nivea respectively. In the oxygen gradient all four species have a preference for water with a high oxygen content. |
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| Keywords: | low shore pool species abundance seasonal abundance seasonal recruitment teleosts |
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