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This work presents the phytosociological characteristics of Todos os Santos Bay mangrove communities in Brazil as well as the chemical composition of the leaves of the three mangrove species and their associated sediment. For the qualitative, phytosociological investigation, the contiguous parcel method was used at five sites associated with petroleum extraction (Site 4, Fontes Island), transportation (Site 2, Madre de Deus and 3, Pati Island), and refining (Site 1, Mataripe). Each site was divided into seven 10 x 10 m parcels. Results indicated that the Todos os Santos mangrove ecosystem has a fringe physiognomy with low bearing, containing the obligate species, Laguncularia racemosa, Rhizophora mangle, and Avicennia schaueriana, the former being the dominant species. The sediment presented a predominantly sandy texture and the average levels of the elements P, Ca, K, Mg, Na, Cu, Zn, Mn, and Fe were within the normal range of variation for this kind of environment. The chemical analysis of leaves revealed significant differences among the species, although Rhizophora mangle and Laguncularia racemosa demonstrated a great similarity in their average concentrations of the minerals N, P, K. Ca, Mg, S, Cu, Fe, Mn, and Zn. For the three species, the individuals collected at Mataripe (Site 1) site, presented significantly higher (p<0.05) concentration of the elements N, P,and Cu, when compared to the others sites, thus suggesting the influence of the oil refinery on mangrove plants.

Reproduction of the isopod Cubaris murina was studied in the laboratory in order to observe the offspring number per brood, the number and duration of the incubation periods, and the influence of repeated mating on number of young per brood. An experiment was conducted with two different groups: female/male pairs and females that were isolated after mating. No significant difference was found between the two reproductive female groups for the mean number of young per brood (x = 25) and the duration of the incubation periods (x = 17 days). One mating was enough for at least five broods, with no reduction in brood size. There was no significant difference between the number of adult males and females. Low-density cultures had a significantly higher growth rate compared to high-density cultures. Furthermore, the experimental results for optimization isopod culture conditions for terrestrial ecotoxicity testing are reported.Keywords: isopods, Cubaris murina, laboratory, reproduction, ecotoxicology.Reprodução de Cubaris murina (Crustacea: Isopoda) em condições de laboratório e seu uso em testes de ecotoxicidade Resumo A reprodução do isópodo Cubaris murina foi investigada em laboratório para observar: o número de filhotes por ninhada, número e duração dos períodos de incubação, e se repetidas cópulas influenciam o número de juvenis por ninhada. Um experimento foi conduzido com dois diferentes grupos: pares com uma fêmea e um macho e fêmeas mantidas individualmente depois da cópula. Não foram encontradas diferenças estatisticamente significantes entre os dois grupos de fêmeas em relação ao número de filhotes por ninhada (x = 25) e a duração dos períodos de incubação (x = 17 dias). Uma cópula foi suficiente para ao menos cinco ninhadas, sem redução em seu tamanho. A proporção sexual dos adultos de C. murina em laboratório não apresentou diferenças significativas entre a proporção de machos e fêmeas nos cultivos. A densidade influencia o crescimento dos isópodos de forma significativa: culturas com baixa densidade têm maior taxa de crescimento do que culturas com alta densidade. Os resultados experimentais sobre a eficiência dos cultivos em laboratório para ensaios ecotoxicológicos terrestres são apresentados.