Banca de DEFESA: ÁLVARO CARVALHO DE LIMA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : ÁLVARO CARVALHO DE LIMA
DATA : 30/05/2019
HORA: 14:00
LOCAL: Sala de aula do DECOL
TÍTULO:

Excretions of Amazonian fishes using Ecological Stoichiometry and Metabolic Theory of Ecology approaches

PALAVRAS-CHAVES:

Excretion rate, N:P ratio, nitrogen, phosphorous, ontogeny

PÁGINAS: 45
GRANDE ÁREA: Ciências Biológicas
ÁREA: Ecologia
RESUMO:

Fishes are important to uptake processes as well as energy and nutrients transfer in aquatic food webs. Fish excretion supplies nutrients for autotroph organisms, representing the main source of nitrogen and phosphorous for primary producers in several freshwater ecosystems. 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 release by fish, measuring their excretions in field conditions. One hundred fifty-three incubation experiments were performed using 59 native species. This thesis is structured in five sections: the first one presents a general introduction; the second section describes the study area, and methods used to get field data and the laboratory analysis; The third section deals about the results, which are presented in form of two independent chapters, each one with a brief contextualization about the problem addressed, results and discussion. The fourth and fifth sections, respectively, present a general conclusion and all the references cited. The main two results showed that: 1) excretion rates were negatively related to body mass and body stoichiometry, while excreted N:P ratio was positively related to body mass. We could reveal the indirect effect of body mass on excretion because body mass also affects body stoichiometry; 2) we used literature data to create a proxy to growth rate, assuming the fish growth is faster as smaller they are far from their maximum size, than we compared body stoichiometry and excretion ratios of juvenile in contrast to adult fishes. Results revealed that growth affects body stoichiometry and excretion ratios in the beginning of the juvenile phase. Overall, our conclusions point out that body size, body stoichiometry and growth affect N and P release by fishes.   

MEMBROS DA BANCA:
Externo à Instituição - CARLOS EDWAR DE CARVALHO FREITAS - UFAM
Externo à Instituição - GUILHERME GERHARDT MAZZOCHINI - UFSC
Interno - 1362202 - JOSE LUIZ DE ATTAYDE
Externo à Instituição - RAFAEL DETTOGNI GUARIENTO - UFMS
Presidente - 1177742 - RONALDO ANGELINI