-ANALYSIS OF SPONGE SPICULES AS PALEOENVIRONMENTAL INDICATORS IN WESTERN BAHIA LACUSTRINE SEDIMENTS.The use of sponge spicules in sediments as proxy data has been successful in paleoenvironmental reconstructions. We recovered two sedimentary cores in two ponds located in San Francisco lowland in Western Bahia to understand the paleoclimatic and the lacustrine system dynamics. Sedimentary facies and granulometric analysis were perfomed. Also, organic matter content and presence of diatoms frustules were studied, besides the identification and quantification of sponge spicules detected in sediments, which were dated by 14 C. The sediment age ranged between 8410 to 3929 yrs cal BP, corresponding to the Holocene. Sponge spicules of the following species were found: Dosilia pydanieli, Heterorotula fistula, Metania spinata, Oncoslera sp., Radiospongilla inesi and Tubella variabilis. Analysis of the results suggest that the two lakes have a standardized climate pattern alternating between drier and wetter climates in relation to the current climate condition. However, the two lakes differ regarding the sedimentation rate and the microfossil content the pond of the northern portion showed lentic and lotic alternated phases, indicating a paleodrainage at the beginning of the upper Holocene, while the evidences in the southern pond of the lake system there are only lentic phases. Such evidences suggest that other physiographic factors and climate influenced the dynamics of these lakes, such as structure, litholog and tectonics of the ponds substrates.Key words: Quaternary, Holocene, San Francisco lowland, sponges.RESUMO -A utilização de espículas de esponjas em sedimentos como dado proxy vem obtendo sucesso em proposições de reconstruções paleoambientais. Para compreender as condições paleoclimáticas e dinâmicas do sistema lacustre, localizado na Depressão do São Francisco, no oeste do estado da Bahia, foram recuperados dois testemunhos em duas lagoas. Foram realizadas análises de fácies, ensaios granulométricos, de conteúdo de matéria orgânica e presença de diatomáceas, além da identificação e quantificação de espículas de esponjas detectadas nos sedimentos holocênicos, que foram datados por 14 C. A idade das amostras dos sedimentos variou entre 8.410 a 3.929 cal. AP. Foram encontradas espículas das esponjas Dosilia pydanieli, Heterorotula fistula, Metania spinata, Oncoslera sp, Radiospongilla inesi e Tubella variabilis. As análises sugerem que as duas lagoas tiveram situações climáticas com alternância entre fases mais secas e mais úmidas em relação ao clima atual. No entanto, as duas lagoas diferem no que tange à taxa de sedimentação e conteúdo microfossilífero. Para a lagoa da porção norte os resultados evidenciaram alternância de fases lênticas e lóticas, indicando uma paleodrenagem no início do Holoceno superior, enquanto as evidências da lagoa ao sul do sistema lacustre indicam apenas fases lênticas. Tais evidências sugerem que outros fatores fisiográficos, além do clima, influenciaram a dinâmica dessas la...

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This paper provides a comprehensive review of the environments where freshwater sponges occur and evaluates the use of sponge spicules as a proxy in paleoenvironmental studies in the Neotropical region. The paper aims to: I) review the information about the ecology of inland sponges to facilitate the use of spicules as a paleoenvironmental tool; and II) identify possible incongruities in the use of this information in paleoenvironmental reconstructions that have been conducted in Neotropical regions. The study compiled data on 77 sponge species, specialist or generalist that occur under certain environmental conditions, such as: substrate type for growth, hydrodynamic types, as well as salinity and acidity concentrations. In addition, it provides a comparison of the paleoenvironmental conditions applied to reconstruction studies that have been carried out within this biogeographic region, highlighting incongruities regarding the current ecology of the sponges.

This paper deals with niphatid sponges from the coast of the Bahia State, northeastern coast of the Brazilian shelf (southwestern Atlantic). Two new species are described, Amphimedon estelae sp. nov. and Niphates luizae sp. nov. A taxonomic study of those samples is given, including description and illustrations. Both species were compared with their congeners present in the Atlantic Ocean.