• M Peer Mohamed

      Articles written in Proceedings – Animal Sciences

    • Influence of ambient oxygen on random activity in some freshwater teleosts

      M Peer Mohamed M N Kutty

      More Details Abstract Fulltext PDF

      The influence of ambient oxygen concentrations on random (spontaneous) activity was tested in four freshwater teleosts (mullet,Rhinomugil corsula, cichlid,Tilapia mossambica, minor carp,Puntius sarana and goldfish,Carassius auratus) at various ambient oxygen concentrations below air saturation at two temperatures 30 and 35° C. A modification of Fry’s respirometer and fish activity counter was used for the experiments. The initial ambient oxygen gradually fell from air saturation to reach the asphyxial level (the concentration at which the fish begin to lose equilibrium) by the depletion of oxygen due to the respiration of the fish itself. Among the four species tested, only inTilapia mossambica the random activity decreased with decrease in ambient oxygen whereas the other three species indicated a reverse trend. The differences in responses of random activity to ambient oxygen may be due to a dichotomy in behavioural evolution and may have a major role in the survival of the species.

    • Metabolic rates and quotients in the cichlid fish,Tilapia mossambica (Peters) in relation to random activity

      M Peer Mohamed

      More Details Abstract Fulltext PDF

      Oxygen consumption, carbon dioxide production and NH3-N excretion increased with increase in random (spontaneous) activity inTilapia mossambica in air-saturated water in tests at 30 and 35° C. The random activity change did not affect the RQ which remained near unity at adequate ambient oxygen. But, the AQ decreased with increase in activity at both 30 and 35° C, suggesting that increased protein utilization in quieter fish when adequate ambient oxygen is available. The routine and standard metabolic rates at 35° C are slightly higher than at 30° C, but, in general, the overall metabolic rates and quotients are significantly in close proximity, suggesting that the temperature range (30–35° C) does not seem to cause a marked metabolic difference inTilapia mossambica.

    • Effects of handling on oxygen consumption and random activity in the freshwater mulletRhinomugil corsula (Hamilton)

      M Peer Mohamed

      More Details Abstract Fulltext PDF

      Handling caused excitement which resulted in lower random activity associated with higher rate of oxygen consumption. The routine and standard oxygen consumption rates were increased by 260 and 238%, and 291 and 277% at 30° and 35° C respectively. The temperature effect (30–35° C) did not cause a marked difference (P < 0·05) in the rate of oxygen consumption and random activity inR. corsula.

    • Influence of hypoxia on metabolism and activity inPuntius sarana (Hamilton) (Pisces: Cyprinidae)

      M Peer Mohamed M N Kutty

      More Details Abstract Fulltext PDF

      InPuntius sarana, changes in metabolic rates in relation to ambient oxygen fell into the general pattern at 30 and 55° C, the differences being mainly in the levels of metabolism, both aerobic and anaerobic. The mean RQs at high ambient oxygen were 0.77 and 0.63 revealing that the fish were aerobic under adequate ambient oxygen. The hypoxic RQ were 1.42 and 1.90 suggesting that the fish derived considerable energy anaerobically. The aerobic AQs ranged between 0.06 and 0.18 depending on the utilization of protein and the hypoxic AQs were in consonance with the corresponding changes in hypoxic RQs. As judged from the asphyxiai oxygen level,P. sarana can live, below air saturation, up to 0.41 and 0.49 mg O2/1 at 30° and 35°C respectively. The random activity of the fish increased with decrease of ambient oxygen.

    • Influence of ambient oxygen and random swimming activity on metabolic rates and quotients in the freshwater mulletRhinomugil corsula (Hamilton)

      M Peer Mohamed M N Kutty

      More Details Abstract Fulltext PDF

      Oxygen consumption and carbon dioxide production increased with increase in random (spontaneous) swimming activity in mullet,Rhinomugil corsula in high oxygen (normoxia), but the oxygen consumption in low oxygen (hypoxia) was negatively correlated with swimming activity in tests at both 30 and 35°C. The RQ of mullet under hypoxia always remained over unity and increased with increase in activity, clearly indicating intense utilization of anaerobic energy. The RQ under normoxia remained near unity irrespective of random swimming activity change. The AQ of normoxic and hypoxic mullet showed opposing trends, the quotient increasing with decreasing activity in the former and increasing with activity increase in the latter. The AQ change suggests increased protein utilization in quieter fish when adequate ambient oxygen is available, but the hypoxic mullet utilizes more protein the more active it is. The latter change in AQ is consonant with the change in hypoxic RQ and it is likely that increased anaerobic energy utilization demanded by the increased activity is accompanied by increased protein breakdown and ammonia release, thereby helping in acid-base balance and ionic (Na+) regulation. Results obtained at 30 and 35°C are almost identical. Within the small range temperature does not seem to cause a marked metabolic difference in mullet.

  •  

© 2021-2022 Indian Academy of Sciences, Bengaluru.