2021-09-162021-09-162021-02-23RUSSO, Camila Ferreira. Dinâmica populacional de Austinixa patagoniensis (Rathbun, 1918) (Decapoda, Pinnotheridae) em uma praia exposta do litoral sudeste do Brasil. Orientador: Marcelo Petracco. 2021. 30 f. Trabalho de Curso (Bacharelado em Oceanografia) - Faculdade de Oceanografia, Instituto de Geociências, Universidade Federal do Pará, Belém, 2021. Disponível em: https://bdm.ufpa.br:8443/jspui/handle/prefix/3498. Acesso em:.https://bdm.ufpa.br/handle/prefix/3498The pinoterid crab Austinixa patagoniensis is a filter feeding decapod and usually inhabits the upper portion of galleries excavated by calyanassid crustaceans of the species Callichirus major, or ecologically similar species. The present study aimed to analyze the population structure and estimate parameters of the population dynamics such as growth and life expectancy of this crab in the intertidal zone of the exposed Una Beach, located at the Juréia-Itatins Ecological Station, south coast of the state of São Paulo, Brazil. The sampling was carried out monthly between October 2004 and November 2005, during low spring tides, in two areas in the northern segment of the beach (area A and area B) that presents dissipative morphodynamic state. There were no samples collected in January 2005 in both areas and in April 2005 only in area B. In each area, a transect was established with sampling stations every 8 meters along the dune-waterline axis. The samples were collected through a manual suction pump in 10 galleries of C. major per station. A total of 662 individuals were collected during the study’s period in the two areas, grouped by the width of the carapace in 0.5 mm size classes and by the observed sex. The age-length key obtained was used to adjust von Bertalanffy's growth function and life expectancy was estimated using the length at which 99% of the population was represented (L99) and the longest observed length (Lmax). In area A, 119 juveniles, 120 females, and 134 males were found, while in area B 85 juveniles, 94 females, and 110 males were observed. The largest size observed for females and males was 11.2 mm and 11.5 mm, respectively. The abundance of A. patagoniensis was determined by the number of individuals collected per C. major gallery. The average density in the areas was approximately 1.19 ind.galeria-1 in area A and 1.04 ind.galeria-1 in area B, the value of the average annual density approached 1 ind.galeria-1 and about 6 ind.m-2. Life expectancy, for both males and females, was about 2 years. Seasonality did not show significant influence on the patterns of temporal distribution and reproduction of the species. A tendency to generate similar estimates was observed, when comparing the population dynamics parameters of A. patagoniensis from the Una Beach with parameters analyzed by other studies on sandy beaches in South America.Acesso AbertoPraias arenosasEcologia de praiasCosta brasileiraBrachyuraSandy beachesBeach ecologyBrazilian coastCNPQ::CIENCIAS EXATAS E DA TERRA::OCEANOGRAFIATrabalho de Curso - Graduação - Monografia