Name: Carolina Bellumat Borges da Silva
Type: MSc dissertation
Publication date: 20/03/2018

Name Role

Examining board:

Name Role
Raphael Mariano Macieira External Examiner *
Maurício Hostim Silva Internal Alternate *
Jean-Christophe Joyeux Internal Examiner *
Angelo Fraga Bernardino External Alternate *

Summary: Popularly known as a Brazilian damselfish, the Stegastes fuscus is recognized as a
key species in infralittoral environments, acting as an ecosystem engineer due to its
territorialist behavior pattern. Considering this possible effect on the coastal reef
habitats, the objective of this study was to evaluate if the species had in fact some
influence on tidepool reef intertidal environments, used as nursery by the species, and
yet so little studied. The Vegetation Cover Rate (TCV) and the percentage of nonforage
environments (sand and rock), inside and outside the territories were compared.
In order to evaluate the variability of the environment independent of S. fuscus, the
relative percentage of macroalgae was used throughout the months of collection. The
environment was very variable, considering the physical and anthropogenic factors, S.
fuscus had no influence on this variables, once the TCV in its territories was similar to
the TCV in the adjacent areas. However, the territories presented less forage areas
(sand and rock) than adjacent unprotected areas, which may be the result of the
animal's ability to allocate its territories in areas with higher food patches, according to
optimal foraging theory. In addition, it was possible to verify that, although reef
environments usually present top-down control, environments of flat reefs are mainly
controlled bottom-up, thus being more susceptible to the physical and anthropogenic
factors, due to the little control and capacity of biological restructuring.