This study concerns the Veneridae bivalves sampled during the research programs "Fauna de Praia/UNICAMP" and "Biota/FAPESP" carried out between August 1995 and July 1997 and between March 2001 and December 2002 respectivelly, in the north coast of São Paulo State, Brazil. A total of 2769 individuals belonging to sixteen species, twelve genera and seven subfamilies were recorded and the characterization of each species improved with detailed redescription and illustrations based on the shell characters. Comparative tables and a identification dichotomic key for subfamilies focused in this study are provided. IntroduçãoA família Veneridae (Mollusca, Bivalvia) reúne aproximadamente 500 espécies viventes, pertencentes à aproximadamente cinquenta gêneros e doze subfamílias (Canapa et al. 1996); essa diversidade está relacionada à grande variedade de habitats para os quais estão adaptados, como praias arenosas, areno-lodosas, manguezais e fundos arenosos em ambientes coralíneos (Cantera 1991), todos ocorrendo no litoral paulista, com exceção de ambientes coralíneos. No Brasil foram registradas 35 espécies de venerídeos, pertencentes a quatorze gêneros e sete subfamílias (Rios 1994). Desse total, 24 espécies, treze gêneros e sete subfamílias têm distribuição que inclui a costa do estado de São Paulo, Brasil (Rios 1994). Dentre os estudos sobre os bivalves da costa brasileira que incluem a família Veneridae, alguns se referem à distribuição geográfica (Morretes 1949;Kempf & Matthews 1968), a aspectos anatômicos e funcionais (Narchi 1972, 1974, Narchi & Gabrieli 1980, Guerón & Coelho 1989Guerón & Narchi 2000;Narchi & Dario 2002), e a uma breve caracterização das espécies (Clench 1942, Fischer-Piette et al. 1970, Rios 1994 Materiais e MétodosExemplares das espécies da família Veneridade coletados pelos programas Fauna de Praia/UNICAMP e Biota/FAPESP, durante o período de agosto de 1995 a julho de 1997 e de março de 2001 a dezembro de 2002, respectivamente, foram analisados sob microscópio estereoscópico e identificados através da bibliografia especializada. Esta última possibilitou a constatação de problemas de ordem taxonômica, os quais são discutidos, quando pertinentes, junto à redescrição detalhada, apresentada para cada espécie e elaborada com base nas conchas coletadas íntegras. Cada redescrição é acompanhada de fotos ilustrativas de estruturas e detalhes relevantes para a caracterização da espécie. As fotos foram obtidas com câmera digital Nikon modelo Coolpix 995, com 3.34 megapixels. As medidas de comprimento, altura e largura, foram feitas com o auxílio de paquímetro digital Mitutoyo modelo CD-6 CS. As medidas mencionadas na redescrição de cada espécie correspondem à do exemplar de maior tamanho presente nas amostras.As diagnoses da família, das subfamílias e dos gêneros foram elaboradas com base nas publicações de Dall (2000) e confirmadas e/ou complementadas com base nos exemplares examinados. A maioria dos espécimes examinados encontra-se depositado na coleção científica do Museu de História Natural da Uni...
ABSTRACT. The spatial distribution of mollusks in the intertidal zone was examined monthly from August 1995 through July 1997, in Enseada, Barra Velha and Araçá beaches in southeastern of Brazil. One study sector was selected in Enseada and Barra Velha, and two sectors in Araçá (Araçá I and Araçá II). The sectors were 10 m wide and equivalent in length to the width of the intertidal zone. Each sector was divided into three horizontal levels: lower, middle and upper, where the samples were taken with a cylinder corer with a base area of 0.16 m 2 . In order to characterize the intertidal environment in these areas, some environmental variables were analyzed. In general, the mollusks were distributed in the sectors as follows: Enseada -Olivella minuta (Link, 1807)
Macoma biota n. sp. is described from material collected in the intertidal zone of Praia da Cidade, Caraguatatuba Bay on the northern coast of the state of São Paulo, Brazil. The species is characterized by its shell features and gross anatomy. The western Atlantic M. constricta (Bruguière, 1792) is the most similar species to M. biota, both hardly distinguishing by their shell characteristics. The main shell feature distinguishing M. biota from M. constricta is the ventral limb of the pallial sinus that is shorter, steeper and confluent with the pallial line along the first quarter of this scar in M. biota, and long, closely parallel to and confluent with the pallial line far posteriorly in M. constricta. Anatomical characters distinguishing M. biota are: ventral channel formed by asymmetrical left and right additional mantle folds; paired, asymmetrical siphonal organs; all four labial palps provided of short conical papillae on their outer surface and simple, acute terminal tip; both demibranchs equally long; and presence of a single short, stout “accessory adductor muscle” adjacent to the cruciform muscle. Macoma constricta has ventral channel formed by the right additional mantle fold only; unpaired, left siphonal organ; all four labial palps lacking papillae on their outer surface and terminal tip of the left inner labial palp produced into a thin sheath with undulated plicae; inner demibranch longer and extending beyond the antero-dorsal limit of the outer demibranch; and “accessory adductor muscle” absent.
Aim The aim of the present study, was to apply two biological indexes based on benthic macroinvertebrates (BMWP and ICB RES-P) using as model the Itupararanga Reservoir to know what the advantages and disadvantages of the application of each index in that environment. Methods The methodology consisted on three stages: 1) macroinvertebrates sampling and determination of limnological variables in situ, and sorting of the organisms in laboratory, 2) taxonomic identification of organisms and 3) determination of the saprobic degree for the collection sites and effectiveness of the application of the BMWP (Biological Monitoring Working Party score system) index and the Benthic Community Index created by CETESB (Environmental Sanitary Company of State of São Paulo) for deep regions (ICB RES-P index). Results The study was performed over two periods (spring/summer and autumn/winter), and 8,841 organisms were sampled and divided in 17 families. The Chaoboridae (genus Chaoborus), Chironomidae (subfamilies Chironominae and Tanypodinae) and Tubificidae families had the most abundant taxa. The saprobic degree of the Itupararanga reservoir region resulted in the general classification of the reservoir as β-α mesasaprobic (βms- αms), considered critical due to its organic charge content. The BMWP index was adapted to the sample points and the scores subsequently obtained ranked the reservoir as category V, representing very poor water quality. The ICB RES-P index classified the sample points in the spring/summer period as having regular water quality, and the autumn/winter period as having good water quality. Conclusions From previous findings, it can be concluded that further study and refinement of the components of both indexes are required in order to effectively assess the quality of water in reservoirs.
The ability to use oxygen from both air and water has been considered key to the colonization of terrestrial environments by invertebrates. The freshwater gastropod Pomacea figulina generally lives submerged, although females lay their eggs mainly above water during nighttime, on the stems of aquatic plants, and the embryos develop inside the air-exposed calcareous egg capsules. However, little is known about the physiological adaptations that the ovipositing females and the developing embryos have developed to breathe in air. In this study, we report sexual differences in the aerial and aquatic oxygen consumption of adults and embryonic respiration in aerially developing egg clusters. We found that the males and females of this species can obtain oxygen from both water and air, although uptake rates for both sexes were much lower in air than in water. Females in air consumed oxygen 42% faster than males, which may be related with the habit of egg laying above water level. Developing embryos inside calcareous eggs obtained oxygen faster when submersed under water than when exposed to air, although embryos near hatching were better able to use oxygen from both air and water than embryos at earlier stages of development. Our data suggest that for P. figulina, laying eggs in the terrestrial environment may be more a strategy for protecting embryos from predators than a respiratory adaptation.
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