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Issue Aquat. Living Resour. Volume 11, Number 2, March 1998 Page(s) 87 - 92 DOI 10.1016/S0990-7440(98)80064-8

Aquat. Living Resour. 11 (1998) 87-92
DOI: 10.1016/S0990-7440(98)80064-8

Metabolic responses of Nephrops norvegicus to progressive hypoxia

André S. C. Schmitt and Roger F. Uglow

Department of applied biology, the University of Hull, Kingston upon Hull, HU6 7RX, England

(Received 12 March 1997; accepted 27 January 1998. Available online 11 November 1999.)

Abstract
This work studied some of the metabolic responses of Nephrops norvegicus to a progressive reduction in water oxygen tension (PwO₂) at 12 °C. Experiments were designed to simulate water quality conditions that may occur during the trade of live crustaceans. Oxygen consumption rates and ammonia efflux rates were found to be constant over a wide range of PwO₂ values (20.4-5.9 kPa). A similar result was found for the difference between post-branchial and pre-branchial oxygen concentrations (20.4-2.6 kPa), obtained from a separate experiment. Anaerobic pathways, however, were activated after PwO₂ reached 6.3 kPa, as blood lactate and glucose concentrations increased from 1.24 ± 0.08 and 1.17 ± 0.19 (T₀ values) to 10.55 ± 8.99 and 3.63 ± 0.89 mg · 100 mL^-1 respectively. N. norvegicus was able to maintain blood pH levels at relatively constant values despite a drop in water pH levels and the accumulation of lactate observed at low PwO₂. Heart rates also remained stable during PwO₂ reductions, but scaphognathite beat rate increased considerably, probably as an attempt to maintain steady weight-specific oxygen consumption rates. N. norvegicus appeared to be well adapted to cope with progressive hypoxia as may occur during holding and transportation procedures.

Key words: Hypoxia / metabolism / Nephrops norvegicus


© Elsevier, IRD, Inra, Ifremer, Cemagref, CNRS 1998

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