The goal of this study was to study the distribution of potential habitat markers (Sr/Ca, Ba/Ca, Mn/Ca and Li/Ca) in water from the Paranaguá Estuarine Complex (Brazil) and to study habitat use patterns of Cathorops spixii through ontogeny employing otolith microchemistry. Fish were caught from three sampling sites while water samples were collected at eight stations covering a salinity range from 4.5–33. Elemental concentrations in otolith and water were determined by LA-ICP-MS and ICP-MS, respectively. When the relationship between salinity and elements or ratios in water was studied, significant positive relationships were found for Sr, Li, Ca, Sr/Ca, and negative for Ba, Mn, Ba/Ca and Mn/Ca (P < 0.05). No relationship was observed between water Li/Ca and salinity. A significant positive correlation was found between otolith edge Sr/Ca and salinity (r = 0.63; P < 0.05), positioning this ratio as the best natural tag for reconstructing environmental histories of C. spixii. Change point analysis (CPA) based on otolith Sr/Ca signature through ontogeny revealed potential migrations between environments with different salinity. According to CPA, the number of displacements among different salinities ranged from 3–9 (6.1 ± 1.9), suggesting high plasticity in the migratory patterns. Ba/Ca, Li/Ca and Mn/Ca peaks were observed on the outer margin of the primordium, and could be influenced by physiological, environmental and maternal factors.
Aim This paper aims to concatenate and update the records of non-native species in a subtropical River, in Southern Brazil, warning about their possible impacts in this and other water bodies. Methods Monitoring was carried out in the Guaraguaçu River, the largest River of the Paraná coastal plain, located in the Atlantic Rainforest biome. Fishes were sampled in two periods: from 2002 to 2007 (monthly) and from 2016 to 2018 (semiannually), and the other organisms were collected in isolated samplings. Results The monitoring recorded the presence of six non-native species of animals in this River – four species of fish (Clarias gariepinus, Ictalurus punctatus, Oreochromis niloticus and Salminus brasiliensis), one invertebrate (Macrobrachium rosenbergii) and one foraminifera (Ammoglobigerina globigeriniformis) introduced by escapes from aquaculture, sport fishing and ballast water. These introductions are problematic because they have the potential to impact upon the endangered native species in the River through predation, competition or novel diseases. Conclusions In Guaraguaçu River the increasing number of introductions is worrying because these species have in common a set of traits that turns them into potential invaders. It is of great importance to keep monitoring their populations in order to detect and minimize their negative impacts on native biota, once there is a conservation unit in the region (Guaraguaçu Ecological Station), with the aim to protect the environment in its pristine condition.
The aim of this study is to characterize Guaraguaçú River (Paraná, Brazil) based on sediment analysis and on the distribution of foraminifers and thecamoebians. In November 2005 thirty-three surface sediment samples were collected from the river bottom with a van Veen grab to perform sediment analysis. Fauna analysis was performed in twenty-three of those samples. Preliminary results are presented here. The river belongs to the estuarine system of Paranaguá Bay (Paraná, Brazil); it is a meandering river with saline intrusions influencing up to 14 km upstream. Close to river mouth salinity varies from 27 to 13; at the middle river varies from 15 to 3 and at the upper river the values range from 3 to 0 (zero). Sand fractions dominate the sediments all over the studied area. Close to river mouth very fine to medium sand prevail with a small percentage of silt and clay. At the middle river fine and very fine sand prevail; silt and clay were find only near the river edges. At the upper river sand grains represent almost 100% of the sediment; fine sand prevails. Along the river total carbonate lies around 1% and 5%, but near the edges of lower and middle river it is higher than 5% (up to 13%). Total organic carbon shows similar trends, remaining bellow 2.5% in most parts; in the lower part it can reach up to 6.6%. Near the edges of middle part it lies between 2.5% and 5.5%. Samples with 50 cm 3 for foraminiferal and thecamoebian analysis were preserved in 4% buffered formaldehyde solution and stained with Bengal Rose. Close to river mouth the following foraminifers occur Bolivina striatula, Cibicides sp., Rosalina globularis, Quinqueloculina laevigata, Cribroelphidium poeyanum, Ammonia tepida, Caronia exilis, Ammobaculites exiguus, Acupeina triperforata, Miliamminina fusca, Paratrochammina stoeni, Portatrochammina sp., Arenoparrella mexicana, Haplophragmoides wilberti, Trochammina inflata, Siphotrochammina lobata and Paratrochammina (L.) guaratibaensis) and the thecamoebians Difflugia oblonga and Difflugia corona. At the middle river occur Anuário do Instituto de Geociências -UFRJ
O objetivo deste trabalho é caracterizar o conteúdo fossilífero dos depósitos que constituem a planície com cordões litorâneos pleistocênica para auxiliar na interpretação dos ambientes de deposicionais, na determinação de paleoníveis marinhos. Foram identificadas as seguintes fácies: areia com estratificação cruzada swaley (Ssw), planar (Sp), acanalada (St), sigmóide (Ssg), de baixo ângulo (Sli); areia com ondulações e laminação cruzada (Sr), maciça (Sm), com acamamento flaser (Sf); lama maciça (Fm) e lama com linsen (Fl). Associados a esta fácies foram observados tubos, moldes de conchas e fragmentos e detritos vegetais. As associações de fácies correspondem a um sistema clástico dominado por ondas com influência de maré num contexto de delta de enchente. Foram identificados dois ichnofósseis: Ophiomorpha atribuída a Callichirus sp e moldes de bivalves. Nos areais ocorrem troncos, raízes e outros fragmentos de madeira associados a lama (fácies Fm e Fl), que foram identificadas como Ilex sp (Aquifoliaceae), Inga sp (Leguminosae Mimosoideae), Calyptranthes sp (Myrtaceae) e Laguncularia racemosa (Combretaceae). Nos testemunhos de sondagens o foraminífero Blysmasphaera brasiliensis, espécies características de mangue e estuários. A amostra de madeira proveniente da fácies de lama maciça (Fm), forneceu idade > 40.000 anos A.P. Tubos de Ophiomorpha atribuídos a Callichirus sp, permitem estimar que o paleonível marinho à época de formação da barreira era de oito 8 m superior ao atual. A espécie Blysmasphaera brasiliensis indica fácies depositadas em ambiente estuarino ou marinho raso.
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