Respiratory adaptations of the burrowing marine teleost Lumpenus lampretaeformis (Walbaum). II. Metabolic adaptations

• Published in: Journal of experimental marine biology and ecology 1988-12, Vol.124 (1), p.43-55
• Main Authors: Pelster, B., Bridges, C.R., Grieshaber, M.K.
• Format: Article
• Language: English
• Subjects: Agnatha. Pisces; Animal and plant ecology; Animal, plant and microbial ecology; Animals; Autoecology; Biological and medical sciences; Burrowing fish; Energy metabolism; Fundamental and applied biological sciences. Psychology; O 2 consumption; Vertebrata
• ISSN: 0022-0981; 1879-1697
• DOI: 10.1016/0022-0981(88)90204-3

Aerobic and anaerobic metabolism in relation to environmental oxygen tensions has been analysed in the burrowing fish Lumpenus lampretaeformis (Walbaum). Under normoxic conditions, the O 2 consumption (M O 2 ) of L. lampretaeformis (weight range 4.7–14.3 g) averaged 2.66 ± 0.41 μmol · g −1 · h −1 at 15 °C. The respiratory quotient (RQ) was 0.82 ± 0.07. Investigation of the enzyme activities of L. lampretaeformis muscle tissue demonstrated a high anaerobic capacity, while the enzymes of aerobic catabolism, e.g., hexokinase and citrate synthase, had very low activities. Measurement of O 2 uptake and ventilation frequency (opercula movements) in relation to declining environmental P O 2 revealed a critical P O 2 (P c) of 50–60 Torr. Defining the critical P O 2 as the transition from aerobic to predominantly anaerobic metabolism, with accumulation of lactate and degradation of creatine phosphate in the muscle tissue, gave a P c value of < 65 Torr. The critical P O 2 is discussed in relation to the prevailing environmental conditions in the burrow water of L. lampretaeformis.