The effect of ration size, temperature and body weight on specific dynamic action of the common cuttlefish Sepia officinalis

The effect of meal size (shrimp Crangon crangon) [0.83-18.82% dry body weight (Dw)] on specific dynamic action (SDA) was assessed in cuttlefish Sepia officinalis (1.03-6.25 g Dw) held at 15 and 20 degrees C. Cuttlefish < 2 g significantly expended less energy in feeding and digesting their meal than cuttlefish > 2 g when given the same quantity of food. Handling, eating and digesting a shrimp meal was temperature dependent with cuttlefish processing and digesting a similar sized shrimp meal faster at 20 degrees C than at 15 degrees C. The proportional increase in oxygen consumption (2.07 +/- 0.02) was not correlated with feeding rate (FR) and was independent of temperature and cuttlefish size. The SDA peak was not correlated with FRs, and increased as cuttlefish size and temperature increased. The mean SDA coefficient was 0.87 +/- 0.07% of the ingested energy; one of the lowest SDA values recorded amongst vertebrates and invertebrates. Daily energy requirements (KJ day(-1)) for S. officinalis were calculated from laboratory estimates of energy losses due to standard (MO(2) (Standard)), routine (MO(2) (Routine)) and feeding (MO(2) (SDA)) oxygen consumption. Laboratory estimates of daily metabolic expenditures were combined with results from previous investigations to construct an energy budget for 1 and 5 g cuttlefish consuming a meal of 5 and 15% Dw at 20 degrees C and the amount of energy available for growth was estimated to be between 35 and 80.3% of the ingested energy.