Flow-rate requirements for captive western rock lobsters (Panulirus cygnus): effects of body weight, temperature, activity, emersion, daily rhythm, feeding and oxygen tension on oxygen consumption

Abstract

Oxygen consumption (Mo 2) of P. cygnus was measured in intermittent flow respirometers. A log–log relationship with body weight (W ) remained constant over the range 15–31 °C. Mo 2 was related to body weight and temperature (T) : log 10 Mo 2 =0.814log 10W +0.051 T – 2.075.I n 400 –500 g lobsters it showed a strong response to acute temperature changes (23 –19 –15 –11 and 23 –27 –31 °C): log 10 Mo 2 = 0.045 T – 2.38. Activity caused a significant (P <0.001) increase in Mo 2, with the response being modulated by temperature and body weight. Lobsters took 5–8 h to recover from exposure to handling and emersion, the duration of the recovery period being longer at higher temperatures. A nocturnal rhythm to oxygen consumption was evident. There was a large and sustained specific dynamic action, with a peak Mo 2 of 2.19 times the standard rate occurring 7 h after feeding. Mo 2 at 23 °C was independent of the oxygen tension down to a critical oxygen tension (P c) of 46.2 Torr, be low which Mo 2 varied directly with the oxygen tension. P c varied with temperature and activity state. The data allow the design of live-holding systems and practices that provide the oxygen requirements of captive P. cygnus . Extra keyword: live holding.