Preferência alimentar de espécies de Aplysia sp. sobre ... - Proac

ABSTRACT
Most marine herbivores are generalist feeders that eat whatever resources are
abundant and available in the environment. Despite that, some opistobranch herbivores
have shown some level of specialization on certain macroalgae through the course of
plant-herbivore interaction evolution, developing the ability to tolerate such defenses by
associating with, living on, consuming and using the chemical compounds produced by
the host plant. In this study we evaluated the food preference of two species of Aplysia
collected at two different places of the coast of Rio de Janeiro State (Praia de Boa
Viagem – Niterói, and Praia do Forno – Armação de Búzios), over the macroalgae Ulva
fasciata, Laurencia filiformis, Osmundaria obtusiloba, Sargassum sp. and Dictyota sp.,
collected at Praia Rasa and at Praia do Forno, both located in the city of Armação de
Búzios. These results were correlated with the feeding behaviour of each species,
wether generalized or specialized. The experiments were performed with living
macroalgae, based on multiple choice assays and statistically analyzed through
comparison of the variation in the biomass from the treatment (consumption) versus
control (autogenic variations), and incorporating autogenic values in the consumption’s
values. Both species of Aplysia significantly exhibited a preference for only one of the
five macroalgae offered, though not the same. However, Aplysia specimens from B.
Viagem consumed Ulva fasciata, while those individuals from P. do Forno ate the
macrolga Laurencia filiformis according to both statistical analysis. The two species of
Aplysia possess specialized feeding behavior as the result of distinct
ecological/evolutionary history, since the species from B. Viagem consume a macroalga
usually eaten by herbivores, while that from P. Forno is specialized to eat the
chemically defended macroalga L. filiformis.
Keywords: Aplysia, food preference, herbivory, macroalgae, especialist, generalist.
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