Gross growth efficiency as a function of food intake level in the “Pulpito” Octopus tehuelchus: A multimodel inference application

Abstract

Multimodel inference theory was used to investigate the relationship between gross growth efficiency (GGE) and food intake level (FI) in Octopus tehuelchus for immature octopus kept at 10 °C and 15 °C. Multimodel inference was carried out using the model averaging methodology over the entire set of candidate models. The main results indicated that in O. tehuelchus GGE is an increasing and asymptotic function of FI showing a maximum approaching the partial growth efficiency (PGE). The model-averaged estimates of PGE and maintenance level (MaL) did not differ from those estimated using the rectilinear relationship between growth and FI in previous work. For FI higher than MaL, both GGE and PGE were higher in immature octopus at 10 °C than octopus at 15 °C. It is noteworthy that as FI increases to a satiability state, the difference between GGE at 10 °C and 15 °C decreases as a potential function of FI. These results would indicate that O. tehuelchus maximizes the energy used in growth by keeping a constant MaL for any value of FI. Multimodel inference theory proved to be an efficient tool to build averaged functions taking each candidate model into account. On the other hand, the present work presents a method to understand the intensity feeding needed to reach an optimum growth efficiency, avoiding wasting of food, work energy and investment for octopus rearing or culture activities.