Agrupamentos de Brachyura relacionados com período nictemeral, sazonalidade, profundidade, temperatura e salinidade (31º 30'S - 30º 00'S, Rio Grande do Sul, Brasil)

Abstract

Jaccart s similarity coeficiente applied to presente/absence data was calculated using NTSY-S software for cluster analysis, relationship among 32 brachyurans species and season allty, depth, bottom salinity and temperature were done for the southem region of Rio Grande do Sul state, Brasil, between 8 anda 200 m depth. Arenaeus cribrarius, callinectes sapidus, hepatus pudibundus, leurocyclus, libinia spinosa, ovalipes trimaculus, portunus spinicar tylus crinitichelis, hexapanopeus angustifrons, hexapanopeus paulensis, homola barbata, lithadia oblique, mesorhoea sexspinosa, parthenope pourtunus spinimanus and rochinia gracilipes were present only during spring and/or summer (seasonal group). Depth levels were slightiy related and there was one group of species exclusive for each. Arenaeus cribrarius, callinectes danae, callinectes ornatus, callinectes sapidus, dissodactylus crinitichelis, portunus spinimanus and lithamnus obliqua occurred from 8-34m, criptodromiopsis, homola barbata, pelia rotunda, pilumnus reticulatus, pinnxa brevipollex, podochela gracilípes, rochina gracilípes, and stenorhynchus seticornis from 35-57m; chasmocarcius typicus and pseudorhombila octodentata from 58-131m, allactaea lithostrota and myropsis quinquespinosa from 132-200m, salinity of 30.0 was the bonndary value for most of the species, but 11 were able to support lower salinities. All the species accepted continental water influence except myropsis quinquespinosa which was only found in salinities higher thar 35.0. libinia spinosa and portunus spinicarpus presented eurybiotic characteristics for all variables, arenaeus cribarius, callinectes sapidus, hepatus pudibundus, leurocyclus tuberculosis and ovalipes trimaculatus also presentd similar characteristics.