Banca de QUALIFICAÇÃO: ÁLVARO CARVALHO DE LIMA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE : ÁLVARO CARVALHO DE LIMA
DATA : 22/11/2018
HORA: 14:00
LOCAL: Departamento de Ecologia
TÍTULO:

Consumer driven nutrient recycling by amazonian fish

PALAVRAS-CHAVES:

Excretion rate; excretion ratio; nitrogen; phosporous; Ecological Stoychyometry; Metabolic Theory of Ecology

PÁGINAS: 85
GRANDE ÁREA: Ciências Biológicas
ÁREA: Ecologia
RESUMO:

Fish are important in processes of uptake, transfer and transformation of energy and nutrients in aquatic food webs. Through their excretions, fish supply nutrients for autotroph organisms, representing the main source of Nitrogen and Phosphorous for primary producers in some fresh water systems. Body size, diet, as well as environment light-nutrient conditions, affect excretion rates and ratios of nutrient recycled by fish. The Amazon basin encompasses the most diverse fish fauna in the world, however nutrient recycling by fish in that ecosystem had never being surveyed so far. The main purpose of this thesis was to assess nitrogen and phosphorus recycling by fish, measuring their excretions in field conditions. One hundred fifty three incubation experiments were performed using 59 wild caught native species. The thesis is structured in three chapters. In the first chapter, nitrogen and phosphorous excretion rates and N:P ratio in excretion by large bodied species (which have maximum length smaller than 10 cm) and by small bodied species (which have maximum length bigger than 15 cm) were evaluated. Results evidence that excretions normalized for body mass were inversely related to variation on fish body mass, while N:P excretion ratio increased with fish body mass. Although, regarding the effect of body mass on excretion rates and N:P excretion ratio, there was no difference between small bodied species to large bodied ones. In the second chapter, excretion rates and N:P excreted by fish living in two different environments: várzea (low light and nutrient rich) and igapó (more light and nutrient poor). Excretion rates were similar, despite differences in the light- nutrient conditions. In the third chapter, the relationship between body N:P and excretion N:P was investigated in omnivorous and carnivorous species. Results revealed that carnivorous fish excrete slightly higher N:P than omnivorous species.

MEMBROS DA BANCA:
Interno - 1714892 - ADRIANO CALIMAN FERREIRA DA SILVA
Interno - 1362202 - JOSE LUIZ DE ATTAYDE
Presidente - 1177742 - RONALDO ANGELINI