Name: GABRIEL COSTA CARDOZO FERREIRA
Type: PhD thesis
Publication date: 26/04/2019
Advisor:
Name |
Role |
|---|---|
| Jean-Christophe Joyeux | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| Angelo Fraga Bernardino | Internal Examiner * |
| Ciro Colodetti Vilar de Araujo | External Alternate * |
| Jean-Christophe Joyeux | Advisor * |
| Ronaldo Bastos Francini Filho | External Examiner * |
| Ryan Carlos de Andrades | External Examiner * |
| Vinicius José Giglio | External Examiner * |
Summary: The trophic ecology of herbivorous fishes is a constantly debated subject. Discussions permeate between how species capture their food till which are their real targets on the reef substrate and how it does imply on their functional roles on the environment. Different biotic and abiotic aspects may influence in this group trophic ecology. Seasonal events such as upwelling may, for example, enrich the whole system as a consequence of the input of cold and nutrient-rich deep waters. Similarly, different sites may present particular characteristics, as benthic composition, directly affecting ingestion and nutrient assimilation by
herbivorous reef fishes. This thesis was conducted in four reef environments along the Brazilian coast:
Natal (state of Rio Grande do Norte), Abrolhos Archipelago (state of Bahia), Guarapari (state of Espírito Santo) and Arraial do Cabo (state of Rio de Janeiro). In the latter, studies were conducted on a seasonal
scale but also in a latitudinal approach when it was compared to the other three sites aforementioned. Was verified that the main items in each species diet trend to remain similar in both approaches: seasonal and latitudinal. However, the nominally herbivorous fishes have presented differences in diet composition and
diversity of ingested items in both scales. Likewise, nutrient assimilation and trophic relationships among species also varied in the latitudinal comparison among sites. This work indicates that nominally herbivorous fishes have specificities regarding their nutritional ecology and that environmental variations
or habitats characteristics must be considered to avoid generalizations on the ecology of such important, diverse, and widely-distributed fishes. Finally, this study expands the comprehension on how herbivorous reef fishes partition the available resources and reinforces that each species function in the ecosystem should not be underestimated by grouping them as single unities without site/species-specific analysis.
