Dietary selection of Tegula atra (Lesson, 1830) as an approximation of preference over different species of macroalgae from south of Chile

Abstract

Among the causes that determine food preference are the properties of diets, consumer or consumer- prey interactions. Due to the challenge of integrating all these causes to assess food preference, it was chosen a measuring the food selection the selection of a particular food type. The food selection was measured thoughout the consumption rate, assuming that those food that satisfy the body’s physiological requirements more quickly, will be most consume. If there is selection for a particular type of food, consumption rate on that food will be different if it is presented as a mono- or mixed- diet. In order to evaluate dietary preference in the black snail Tegula atra,manipulative experiments of selectivity were carried out with individuals from two localities in Southern Chile: Bahía Metri (Puerto Montt) and Punta Santa Ana (strait of Magellan). The specimens were exposed to monospecific diet of macroalgae and macroalgae mixed-diet. The results of consumption rate showed the capacity of this organism to feed on varied species of macroalgae, but also certain selective behaviours, mainly due to the greater consumption of the macroalgae, Macrocystis pyrifera. These results coincide with the frequency of co-occurrence of both species on their natural environment.