Name: Marcella Bueno Ribeiro
Type: MSc dissertation
Publication date: 04/03/2020
Advisor:
Name |
Role |
|---|---|
| Kyria Santiago do Nascimento | Co-advisor * |
| Luisa Maria Sarmento Soares Filho | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| Gabriel Fernando Rezende | External Alternate * |
| Kyria Santiago do Nascimento | Co advisor * |
| Leonardo Evangelista Moraes | External Examiner * |
| Luisa Maria Sarmento Soares Filho | Advisor * |
| Savana de Freitas Nunes | External Examiner * |
Summary: The present study was developed with the objective of
investigating the food trophic structure of stream fishes in
relation to temporal seasonality (dry and rainy seasons) in the
Itaúnas River Basin, within the scope of the Córrego Grande
Biological Reserve, far north of Espírito Santo. Primary data
were obtained in 2013, during the rainy season and repeated, with
the selection of four study points, in 2018 during the dry
season. the study points were inside the Biological Reserve, in
Riacho Doce and in its buffer zone, in the Grande and Dourado
streams. The specimens were collected with the aid of butterfly
net and trawl net. The characterization of the taxonomic
composition of the ichthyofauna occurred through the use of
ecological descriptors such as abundance, species richness and
diversity, in addition to the analysis of the Frequency of
Occurrence of the species. A total of 1991 individuals were
collected, distributed in five orders, 11 families and 27
species. 11 species were chosen for the analysis of stomach
contents, based on their constant or occasional occurrence, in
addition to species considered rare and threatened with
extinction such as Mimagoniates sylvicola and Acentronichthys
leptos. Abundant populations of Mimagoniates microlepis, a
species not found outside the protected area, were registered in
the reserve, as well as Aspidoras virgulatus, also found in
forested streams. The analysis of the fish diet was made based on
the analysis of stomachs and food items, inferred by the
investigation of the frequency of occurrence of food items in the
stomach contents, degree of digestion and degree of repletion.
The fish were distributed in trophic guilds based on the main
food consumed. The main source of food was of native origin,
during the rainy season, especially larvae and aquatic insect
nymphs; while in the dry season, the origin of most food items
was alien, such as terrestrial arthropods that fall from the
surrounding vegetation and remains of the riparian vegetation
itself. The results indicate that the stream environments are
interdependent in relation to the surrounding forest, food, shade
and shelter that comes from riparian vegetation. A number of
investigated aquatic organisms exist only within the protected
area. The adoption of more environmentally friendly agricultural
practices around the reserve will contribute to the protection of
fish both within the reserve and in its buffer zone.
