Banca de DEFESA: FERNANDA LEAL LORDERS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : FERNANDA LEAL LORDERS
DATA : 24/03/2017
HORA: 09:00
LOCAL: Salão Nobre IBIO
TÍTULO:

Spongivory by fishes on South Atlantic coral reefs: no evidences of 

top-down control in assemblage level

PALAVRAS-CHAVES:

Predation; Angelfishes; Porifera; Sponge-coral interaction 

PÁGINAS: 55
GRANDE ÁREA: Ciências Biológicas
ÁREA: Ecologia
SUBÁREA: Ecologia Aplicada
RESUMO:

Predator-prey dynamics can affect assemblage structure and ecosystem process representing a central theory in ecology. In coral reef ecosystems, recent evidences have suggested that sponge assemblages in high diversity sites in Caribe are controlled by reef fishes (i.e. top-down control). However, this was not evaluated on South Atlantic reefs, an important region with high endemism and relatively low diversity of hermatypic coral. This study investigated the influence of fish predators on sponge assemblage structure in coral reefs in Todos os Santos Bay, Bahia, Brazil. We investigated whether sponge cover negatively respond to spongivorous fish density, spongivorous fishes foraging preferences and potential spongivory effects on competitive interactions between sponges and hermatypic corals. The results showed that fish predation do not control sponge assemblages. However, there was a significant negative relationship between Scopalina ruetzleri cover and Pomacanthus arcuatus density, indicating specific top-down control. The selected sponges by spongivorous were Desmapsamma anchorata, Scopalina ruetzleri, Aplysina cauliformis and Niphates erecta, knowed as palatable to chemically not tolerated species. The increase of spongivorous density did not reflect in significant decrease of coral-sponges encounters. Thus, we suggest that effects of spongivorous fishes on sponges cover and competitive interactions with hermatypic corals might be weak in South Atlantic coral reefs. We discuss how local human impacts (e.g. fishing and nutrients input) can influence the observed patterns and that management plans must urgently be implemented in marine protected areas in the region, suggesting a reassessment of pre-established quotas of fishery for ornamental proposes. 

MEMBROS DA BANCA:
Interno - 859.394.105-29 - ANTOINE LEDUC - NENHUMA
Interno - 1522389 - FRANCISCO CARLOS ROCHA DE BARROS JUNIOR
Externo à Instituição - GUILHERME RAMOS DA SILVA MURICY - UFRJ