title: Effect of environmental factors on the abundance of decapod crustaceans from soft bottoms off southeastern Brazil.
abstract: This study investigated the importance of variations in environmental factors affecting the abundance patterns of decapods on the southeastern Brazilian coast. Sampling was carried out monthly from January 1998 through December 1999 in Ubatumirim and Mar Virado, Ubatuba region, using a commercial shrimp fishing boat equipped with double-rig nets. Six areas adjacent to rocky shores were chosen. Bottom-water samples were collected using a Nansen bottle, to measure the temperature and salinity. Sediment samples were also obtained by means of a Van Veen grab, for determination of texture and organic-matter content. The association of environmental factors with species abundance was evaluated by Canonical Correspondence Analysis (α = 0.05). Forty-one species of Decapoda were used in the multivariate analysis. The analysis indicated that sediment texture (phi) and bottom temperature were the main factors correlated (p < 0.05) with the spatial and temporal abundance of the species. Considering the study region as faunal transition zone, including a mixture of species of both tropical and subantarctic origin, the species responded differently to environmental factors, mainly temperature. It is conceivable that the decapods adjust their distribution according to their intrinsic physiological limitations, possibly as a result of the available resources.
authors.affiliation: Universidade Estadual Paulista, F Instituto de Biociências, Departamento de Zoologia, BotucatuSP, Brasil.
authors.forename: Michele
authors.initials: M
authors.lastname: Furlan
authors.affiliation: Universidade Estadual Paulista, F Instituto de Biociências, Departamento de Zoologia, BotucatuSP, Brasil.
authors.forename: Antonio L
authors.initials: AL
authors.lastname: Castilho
authors.affiliation: Universidade Estadual do Piauí, ParnaíbaPI, Brasil.
authors.forename: Lissandra C
authors.initials: LC
authors.lastname: Fernandes-Góes
authors.affiliation: Universidade Estadual do Sudoeste da Bahia, Departamento de Ciências Naturais, Vitória da ConquistaBA, Brasil.
authors.forename: Vivian
authors.initials: V
authors.lastname: Fransozo
authors.affiliation: Universidade Estadual Paulista, RegistroSP, Brasil.
authors.forename: Giovana
authors.initials: G
authors.lastname: Bertini
authors.affiliation: Universidade Estadual Paulista, Faculdade de Ciências, Departamento de Ciências Biológicas, BauruSP, Brasil.
authors.forename: Rogério C da
authors.initials: RC
authors.lastname: Costa
mesh_terms: D000818:Animals; D001938:Brazil; D033364:Decapoda / Q000145:classification*; D017753:Ecosystem; D004784:Environmental Monitoring; D019015:Geologic Sediments; D015999:Multivariate Analysis; D011156:Population Density; D011157:Population Dynamics; D054712:Salinity; D013696:Temperature