نتایج جستجو برای: larger benthic foraminifera
تعداد نتایج: 254174 فیلتر نتایج به سال:
Evolution of planktic organisms from benthic ancestors is commonly thought to represent unidirectional expansion into new ecological domains, possibly only once per clade. For foraminifera, this evolutionary expansion occurred in the Early-Middle Jurassic, and all living and extinct planktic foraminifera have been placed within 1 clade, the Suborder Globigerinina. The subsequent radiation of pl...
The discovery that foraminifera are able to use nitrate instead of oxygen as an electron acceptor for respiration has challenged our understanding of nitrogen cycling in the ocean. It was thought before that only prokaryotes and some fungi are able to denitrify. Rate estimates of foraminiferal denitrification have been very sparse and limited to specific regions in the oceans, not comparing sta...
abtalkh formation is a part of late cretaceous sedimentary unit in the kopet- dagh basin, ne iran. this study deals with the study of this formation in the eastern parts of the basin in padeha village. it thickness is about 991m, and lithologically consists of grey, greyish to blue shale and marl. the lower contact with abderaz formation is conformable and transitional, but the upper boundary w...
Large benthic foraminifera are unicellular calcifying reef organisms that can form symbiotic relationships with a range of different microalgae. However, the cellular functions, such as symbiosis and calcification, and other aspects of cellular physiology in large benthic foraminifera are not fully understood. Amphisorus kudakajimensis was used as a model to determine the detailed cellular char...
Abstract We analyze the spatial distributions of two groups of benthic foraminifera (Adelosina spp. + Quinqueloculina spp. and Elphidium spp.), along Sicilian coast, and their correlation with six different heavy metals, responsible for the pollution. Samples were collected inside the Gulf of Palermo, which has a high level of pollution due to heavy metals, and along the coast of Lampedusa isla...
Factors influencing the composition of shallow water benthic foraminifera along the SW coast of South Africa at two locations (Table Bay, TB; St Helena Bay, SHB) ∼200km from each other were examined. Small taxa dominated in both locations; living assemblages from SHB (28 species, Ammonia parkinsoniana dominant) differed from TB (34 species, Elphidium articulatum dominant). Environmental paramet...
Many species of Indo-Pacific holobenthic foraminifera have been introduced and successfully established sustainable populations in the Mediterranean Sea over the past few decades. However, known natural and anthropogenic vectors do not explain how these species were introduced long distances from their origin. We present evidence for a novel marine bioinvasion vector explaining this long-distan...
Dockyards and harbors are recognized as being important locations where sediment-associated pollutants can accumulate, which constitutes an environmental risk to aquatic life due to potential uptake and accumulation of heavy metals in the biota. The aim of this paper is to assess the concentrations and the effects of some heavy metals in the benthic foraminifera assemblage in Niterói Harbor. Lo...
Increased atmospheric CO2 concentrations lead to decreased pH and carbonate availability in the ocean (Ocean Acidification, OA). Carbon dioxide seeps serve as ‘windows into the future’ to study the ability of marine invertebrates to acclimatise to OA. We studied benthic foraminifera in sediments from shallow volcanic CO2 seeps in Papua NewGuinea. Conditions follow a gradient from present day pH...
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