Oxygen consumption in spider crab (Maja brachydactyla): Effect of weight, temperature, sex, feeding and daily light–dark cycle

Spider crab (Maja brachydactyla) is considered a species of potential interest for intensive aquaculture, although physiological studies are necessary before the optimal conditions for its culture can be established. In this paper we develop equations to explain the oxygen consumption of the species as a function of weight (W: 15–1414 g), temperature (T: 13.5–27.9 °C), sex (S) and daily light–dark cycle (14L/10D to 10L/14D). The measurements were carried out over three days on single animals receiving one meal of mussels to satiation only on the first day of the measurements. The oxygen consumption values were divided into routine (MO2routine), post-prandial (MO2sda), maximum peak (MO2peak) and daily average between 0–24 h (MO2;0–24 h), 24–48 h (MO2;24–48 h) and 48–72 h (MO2;48–72 h) post-feeding. Feeding led to an increase in oxygen consumption 1.7–7.3 (2.90 ± 1.25) times the routine value, with maximum peaks between 2 and 16 h post-feeding (7.94 ± 4.12 h) the effect lasting 10–24 h (19.80 ± 3.56 h). The different levels of oxygen consumption were expressed as lnMO2routine = 0.206 + 0.837lnW + 0.302T − 0.006T2 − 0.153S, lnMO2sda = 0.294 + 0.736lnW + 1.372lnT − 0.171S, lnMO2peak = 3.032 + 0.667lnW + 0.083T − 0.158S and lnMO2;0–24 h = 0.403 + 0.769lnW + 1.305lnT − 0.147S, all to a statistically significant degree (P < 0.001) and explaining a percentage of variance above 92%. Although some specimens showed higher oxygen consumption during the night, in the overall analysis of the data the light–dark cycle did not have a statistically significant influence. Interspecific comparisons point to lower oxygen consumption rates other fish and cephalopods of aquacultural interest, and similar to that of other crustaceans in the same experimental conditions.