Banca de DEFESA: REGIANE MÔNICA DOS REIS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : REGIANE MÔNICA DOS REIS
DATA : 25/11/2020
HORA: 14:00
LOCAL: Campus Universitário de Rolim de Moura
TÍTULO:

AGE AND GROWTH OF Serrasalmus rhombeus, AN AMAZON PREDATOR FISH

PALAVRAS-CHAVES:

Growth dimorphism, Growth models, Retrocalculation. Otoliths.

PÁGINAS: 59
GRANDE ÁREA: Ciências Biológicas
ÁREA: Ecologia
SUBÁREA: Ecologia Aplicada
RESUMO:

The growth pattern is one of the most important biological characteristics in terms of assessing population dynamics and managing natural stocks. The Amazonian ichthyofauna is considered one of the largest in the world, with about 2,406 valid fish species. Among this vast biodiversity is the "piranha-preta" (Serrasalmus rhombeus), a predatory fish that acts by regulating the abundance of other species, thus playing a fundamental role in the balance of aquatic ecosystems. In order to generate biological data on ichthyofauna species and contribute to appropriate management plans and the conservation of Amazonian fishery resources, this study aimed to estimate the somatic growth parameters for S. rhombeus and to assess whether there is a difference in growth trajectories between individuals, sex and location. The sampling was carried out with bimonthly collections in the reservoirs of the SHPs Ângelo Cassol and Cachimbo Alto located in the Branco River, Rondônia, between October 2018 and November 2019. The analysis of the marginal increment based on data from 163 otoliths indicated the formation of a single annual ring between February and April, at the peak of the rainy season. Based on the reading of the growth rings, the age for the captured individuals ranged from one to nine years. The retrocalculation method was applied to establish length estimates at ages prior to capture. Three mixed non-linear growth models, based on the von Bertalanffy equation, were constructed considering the individual effect as a random factor, while sex and location were considered as fixed factors. The Akaike Information Criterion (AIC) was used to decide between the three models, which better explains the growth parameters of S. rhombeus. The best model that explained the variation in length in age was obtained by the model that considered individual variation and gender, followed by the model that considered an individual and local variation. The results show that the growth of S. rhombeus varies between individuals and sex. In this way, sex is a source of variation in growth for the species, with growth dimorphism in favor of females. Thus, the biological data and the individual growth trajectories constructed in this study can be used as subsidies for the management and conservation of Amazonian fishing resources, as such information makes it possible to make predictions of the effect of the species on the structure of the fish community in reservoirs.

MEMBROS DA BANCA:
Presidente - 2248433 - IZAIAS MEDICE FERNANDES
Interno - 1798567 - PAULO VILELA CRUZ
Externo à Instituição - LUCIA APARECIDA DE FÁTIMA MATEUS - UFMT
Externo à Instituição - JHONY VENDRUSCOLO - UFAM
Externo à Instituição - MARÍLIA HAUSER DOS SANTOS - FIMCA