CORRELATES OF GROWTH AND FEEDING IN LABORATORY-MAINTAINED ELEDONE-CIRRHOSA (CEPHALOPODA, OCTOPODA)

Octopuses (Eledone cirrhosa (Octopoda: Cephalopoda)) held in an aquari um were subjected to varying conditions of feeding and starvation to e valuate putative indices of feeding and growth. Specific growth rate ( %d(-1)) was linearly related to feeding rate (% of the body mass d(-1) ) in animals with a mean body mass of 250 g at 15 degrees C. Maximum g rowth rates varied between >2% d(-1) (body weights <300 g) to <1% d(-1 ) (body weights less than or equal to 900 g) but specific growth rates were not related to body weight. Growth rates became negative (weight loss) after one week without food. The digestive gland index (DGI) wa s significantly correlated with short and long-term feeding and specif ic growth rates, and with body weight. Muscle RNA concentration was li nearly correlated with growth rate during the previous 1-3 weeks but n ot with feeding rate. RNA:protein ratios were not different between mi d arm and mantle sample sites but arm tip values were significantly hi gher. RNA:protein ratio was related to body weight only in feeding ani mals. It is concluded that DGI is an index of feeding rate and that RN A:protein ratio can be used as an index of recent (similar to 4 weeks) growth rate.