Toxicity ranking of estuarine sediments on the basis of Sparus aurata biomarkers

Sparus aurata biomarkers were used to rank sediments from the Sado River estuary (Portugal) according to their toxicity. Initially, the activities of liver ethoxyresorufin-O-deethylase, liver and gill glutathione S-transferases, muscle lactate dehydrogenase, and brain acetylcholinesterase were tested in a laboratory bioassay with the reference compound benzo[a]pyrene. Enzymatic activities were determined in different tissues of fish exposed for 48, 96, or 240 h to three concentrations of benzo[a]pyrene (25, 50, and 100 g/L). Induction of liver ethoxyresorufin-O-deethylase was observed at all the exposure periods and concentrations, suggesting a continuous response of this system to toxicant exposure. Induction of liver glutathione S-transferases activity was only observed after 240 h of exposure, whereas gill glutathione S-transferases activity was significantly inhibited at all the exposure periods, suggesting a direct or indirect effect of the toxicant on these enzymes. Inhibition of lactate dehydrogenases activity was only observed after 96 h of exposure to 25 g/L of benzo[a]pyrene. No significant effects were observed on acetylcholinesterase activity, suggesting that cholinergic function of S. aurata is not affected by benzo[a]pyrene. In a second phase, fish were exposed for 240 h to sediments collected at five sites of the Sado River estuary, and the same biomarkers were analyzed. For all the enzymes assayed, significant differences among sites were found. In this study, the battery of biomarkers used allowed to discrimination among sites with different types of contamination, levels of contamination, or both, after multivariate data analysis. Discrimination of sites was similar to the ranking provided by a more complex and parallel study (including chemical analysis of sediments, macrobenthic community analysis, amphipod mortality toxicity tests, and sea urchin abnormality embryo assays), suggesting its suitability to evaluate the toxicity of estuarine sediments.info:eu-repo/semantics/publishedVersio

Phenotypic variation of Fucus ceranoides, F. spiralis and F. vesiculosus in a temperate coast (NW Portugal)

Brown algae includes several species of Fucus, reported both in the tidal and intertidal zones of cold and temperate regions. Environmental parameters induce wide biological variability in intertidal algae, manifested by alterations at several levels, and this has lead to the failure of some reports to discriminate between closely related taxa, particularly Fucus species. As the genus Fucus is widely represented on the Portuguese coast, the biometric parameters of three species (F spiralis, F. vesiculosus and F. ceranoides) collected from several sampling sites in Portugal, were studied over twelve months. Environmental parameters (water temperature, pH, dissolved oxygen, salinity, phosphorous - orthophosphate and total phosphate, nitrate, nitrite and ammonia) were analysed. The objective of this study was to understand how environmental parameters influence and establish morphological variation in the Fucus species. Canonical Correspondence Analysis (CCA), which helps define the relationships between morphological and physicochemical variables, was carried out for each species in order to determine which physicochemical parameter most affects the morphology of Fucus. The variable biometric that strongly separates the three Fucus species is the number of receptacles per thalli, and this parameter was highly correlated with F ceranoides. The two others species were distinguished principally by the height of the bigger receptacle, the midrib height of the holdfast, the height of the smaller receptacle, and the midrib width of the holdfast. The CCA analysis also showed that the dominant factor influencing morphometric parameters was salinity, being always in strict correlation with water temperatures and orthophosphate. For F ceranoides, physicochemical parameters (especially a higher concentration of orthophosphate and lower salinity) seem to influence morphological parameters, mainly in the raised number of receptacles per thalli. Salinity was the most important environmental parameter to distinguishing F spiralis and F vesiculosus in northern Portugal.FCT/CONTROL project - PDCTM/C/MAR/15266/199

Características termorreguladoras e desempenho de cabras leiteiras no terço inicial da lactação em clima tropical.

Resumo: Teve-se como objectivo avaliar o comportamento de características termorreguladoras, a condição corporal e a produção de leite no início da lactação de 45 cabras de diferentes tipos raciais (15 da raça Saanen, 15 cruzadas Sem Padrão Racial Definido (SPRD) x Murciana e 15 Alpinas Americanas). Foram tomadas a temperatura retal, a freqüência respiratória, o escore da condição corporal a produção diária de leite e as concentrações plasmáticas de triiodotironina (T3) e tiroxina (T4) avaliados até os 36 dias da lactação. As concentrações de T3 e T4 foram obtidas pelo método de radioimunoensaio. As variáveis meteorológicas foram registradas às 15 h, no mesmo horário da coleta dos dados fisiológicos. Os resultados obtidos indicaram que as cabras da raça Alpina Americana tiveram as maiores temperaturas retais e frequencias respiratórias, além de menores concentrações de triiodotironina e tiroxina, associados a menor produção de leite e condição corporal possivelmente como reflexo de menor adaptação ao clima. As cabras Saanen e _ Murciana SPRD apresentaram menores temperaturas retais e frequencias respiratórias, maior escore da condição corporal e concentrações séricas de triiodotironina e tiroxina. As temperaturas retais foram iguais entre os grupos genéticos _ SPRD x _ Murciana e diferente para as cabras saanen. No terço inicial de lactação animais mestiços leiteiros juntamente com as cabras Saanen, demonstraram maior adaptabilidade, bom desenvolvimento corporal e melhor desempenho lactacional. As cabras Alpinas Americanas mostraram menores respostas adaptativas e produtivas o que evidencia a importância do ambiente térmico na criação desses animais. [Thermoregulatory traits and performance of dairy goats in early lactation in tropical weather]. Abstract: The objective of this study was to evaluate physiological and performance characteristics in early lactation of dairy goats of several breeds, namely thermoregulation, body condition and milk production. Forty five females were used (15 Saanen, 15 of crosses between undefined breed and _ Murciana and 15 American Alpine). Records were made of rectal temperature, respiratory rate, body condition score and daily milk production in the 36 first days of lactation. Plasma concentrations of triiodothyronine and thyroxine were obtained by radioimmunoassay method. The meteorological variables were registered at 15 pm, at the same time as the collection of physiological indicators. Results indicate that American Alpine goats had higher rectal temperatures and respiratory frequency, lower concentration of triiodothyronine and thyroxine, associated to a smaller milk production and body condition, possibly due to the worse climate adaptation. Saanen and _ Murciana crosses presented lower rectal temperatures and respiratory frequency, higher body score and triiodothyronine and thyroxine concentrations. Rectal temperatures were similar between the genetic groups undefined breed x _ Murciana and different for Saanen goats. In the initial third of lactation crossbred goats along with Saanen goats showed greater adaptability, good physical development and better milk production. The American Alpine goats showed less productive and adaptive responses which highlights the importance of the thermal environment in the management of these animals

Characterization of Cholinesterases in Plasma of Three Portuguese Native Bird Species: Application to Biomonitoring

Over the last decades the inhibition of plasma cholinesterase (ChE) activity has been widely used as a biomarker to diagnose organophosphate and carbamate exposure. Plasma ChE activity is a useful and non-invasive method to monitor bird exposure to anticholinesterase compounds; nonetheless several studies had shown that the ChE form(s) present in avian plasma may vary greatly among species. In order to support further biomonitoring studies and provide reference data for wildlife risk-assessment, plasma cholinesterase of the northern gannet (Morus bassanus), the white stork (Ciconia ciconia) and the grey heron (Ardea cinerea) were characterized using three substrates (acetylthiocholine iodide, propionylthiocholine iodide, and S-butyrylthiocholine iodide) and three ChE inhibitors (eserine sulphate, BW284C51, and iso-OMPA). Additionally, the range of ChE activity that may be considered as basal levels for non-exposed individuals was determined. The results suggest that in the plasma of the three species studied the main cholinesterase form present is butyrylcholinesterase (BChE). Plasma BChE activity in non-exposed individuals was 0.48±0.11 SD U/ml, 0.39±0.12 SD U/ml, 0.15±0.04 SD U/ml in the northern gannet, white stork and grey heron, respectively. These results are crucial for the further use of plasma BChE activity in these bird species as a contamination bioindicator of anti-cholinesterase agents in both wetland and marine environments. Our findings also underscore the importance of plasma ChE characterization before its use as a biomarker in biomonitoring studies with birds

GM 01. Study of some fertility indices of dairy herds monitored by computerized information systems

The objective of this work is to verify the tendency of some fertility indices of monitored dairy herds from 1992 to 1995. In developed countries the use of computerized information systems has contributed significantly to the increase milk production. Data from a program of monitoring dairy farms developed by the “Estação Experimental de Zootecnia de Ribeirão Preto, IZ/SAA, SP, Brasil” were studied from 1992 to 1995. The fertility indices used to assess the performance are described: a) calving interval to conception (days); b) days open; c) percentage of cows that re-calved; d) number of services per conception. There was a tendency for the calving interval to conception to decrease over the years. This indice is a good parameter to assess herd efficiency. It reflects improvements of the herds in cow fertility, heat detection efficiency and artificial insemination. The days open take into account all cows that did not yet conceive within 12 month period, hence it shows the poorest cows in the herd. Surprisely, the percentage of cows that re-calved tended to decrease over the years. This work showed that it is difficult to state if the herd performance has improved or not based only in the studied indices. The results suggested that many factors are involved when assessing dairy herd fertility indices, specially in developing countries where milk policy does not always motivate the dairy farmer to have a tight policy with his cows. It is also important to understand that over the years farmers have learnt ‘what’ and ‘how’ to record, as a consequence, some fertility indices seemed to be worse but they were more realistic than previous figures. Educational programmes for dairy farmers on the information needs and use for farm management should be supported and implemented

Differences in the macrozoobenthic fauna colonising empty bivalve shells before and after invasion by Corbicula fluminea

Bivalve shells can potentially alter the structure of aquatic benthic communities. However, little is known about the effect that different shell morphologies have on their associated fauna. This study aimed to understand how empty shells, from four different freshwater bivalve species, affect macrozoobenthic communities, using the River Minho (Iberian Peninsula) as a study area. Three native (Anodonta anatina, Potomida littoralis, Unio delphinus) and one non-indigenous (Corbicula fluminea) species were used for this research. Comparisons among species and between scenarios (i.e. before and after invasion by C. fluminea) were performed. Our results suggest that macrozoobenthic community structure did not vary among treatments, with the exception of species richness, which was higher on shells of native species. Furthermore, little difference was detected when comparing scenarios with and without C. fluminea shells, despite dissimilarities in size and morphology between species. The empty shells of C. fluminea partially (in terms of density and biomass, but not in species richness) replaced the role of empty shells of native species as a physical substratum for the associated macrozoobenthic community.Martina Ilarri is supported by a Post-doc grant (SFRH/BPD/90088/2012) from the Portuguese Foundation for Science and Technology – FCT through POPH/FSE funds. This study was conducted within the scope of the project ECO-IAS: Ecosystem-level impacts of an invasive alien species, supported by FCT and COMPETE funds (contract: PTDC/AAC-AMB/116685/2010) and was also partially supported by the European Regional Development Fund (ERDF) through COMPETE funds (PEst-C/MAR/LA0015/2011) and by FCT/MEC through Portuguese funds (PIDDAC – PEst-OE/BIA/UI4050/2014).info:eu-repo/semantics/publishedVersio

Akutna oralna toksičnost organofosfornih insekticida i inhibicija kolinesteraza u pilića

Acute toxic effects of three commonly used insecticidal preparations of the organophosphates chlorpyrifos, diazinon, and dichlorvos were examined in mixed breed broiler chicks, and cholinesterase activity in plasma and brain were measured. The acute (24 h) oral median lethal doses (LD50) of chlorpyrifos, diazinon, and dichlorvos were 10.79 mg kg-1, 6.32 mg kg-1, and 6.30 mg kg-1, respectively, as determined by the up-and-down method in chicks. Signs of cholinergic toxicosis in the chicks appeared within two hours after dosing, and they included salivation, lacrimation, gasping, frequent defecation, drooping of wings, tremors, convulsions, and recumbency before death. Halving the oral LD50 of chlorpyrifos (5 mg kg-1), diazinon (3 mg kg-1), and dichlorvos (3 mg kg-1) caused immobility and wing drooping, but not the clinical signs of cholinergic toxicity. However, at full LD50 doses of these insecticides, chicks showed clinical signs of cholinergic toxicity similar to those seen in the LD50 experiments. Two out of six chicks died within two hours after treatment with LD50 doses of chlorpyrifos and dichlorvos, whereas LD50 dosing with diazinon caused death in three out of six chicks. Compared to control values, the insecticides reduced plasma and whole brain cholinesterase activities by 29 % to 84 % and 18 % to 77 %, respectively, depending on the dose. The decrease in plasma cholinesterase correlated well (r = 0.82) with that of the brain. These data suggest that organophosphate insecticides administered orally at LD50 doses induce clinical signs of cholinergic poisoning and concurrently reduce brain and plasma cholinesterase activities in chicks.Ispitano je akutno toksično djelovanje triju često rabljenih organofosfornih insekticida klorpirifosa, diazinona i diklorvosa u brojlera te je izmjerena aktivnost kolinesteraza u njihovoj plazmi i mozgu. Srednja letalna doza LD50 klorpirifosa iznosila je 10,79 mg kg-1, diazinona 6,32 mg kg-1 te diklorvosa 6,30 mg kg-1. Prvi su se znakovi kolinergičkoga sindroma u pilića javili unutar dva sata od oralne primjene, a obuhvaćali su slinjenje, suženje, teško disanje, učestalu defekaciju, obješena krila, drhtavicu, grčenje i nesposobnost stajanja uoči smrti. Oralna primjena polovice srednje letalne doze insekticida klorpirifosa (5 mg kg-1), diazinona (3 mg kg-1) i diklorvosa (3 mg kg-1) dovela je do nepokretnosti i obješenih krila, ali bez kliničkih znakova kolinergičke toksičnosti koji su uočeni kod pokusa radi utvrđivanja srednje letalne doze (LD50). Međutim, doze ovih insekticida koje su odgovarale LD50, dovele su do kliničkih znakova kolinergičke toksičnosti sličnih onima zamijećenim kod utvrđivanja LD50. Dva od šest pilića uginula su unutar dva sata od primjene bilo klorpirifosa bilo diklorvosa u dozama koje su odgovarale LD50, dok je diazinon u odgovarajućoj srednjoj letalnoj dozi uzrokovao smrt triju od šest pilića. U odnosu na kontrolne vrijednosti, insekticidi su doveli do smanjenja aktivnosti kolinesteraze koja je ovisila o dozi, a kretala se od 29 % do 84 % u plazmi te od 18 % do 77 % u mozgu. Pad aktivnosti kolinesteraze u plazmi dobro je korelirao s njezinim padom u mozgu (r=0,82). Ovi podaci upućuju na to da oralna primjena organofosfornih insekticida u dozama koje odgovaraju srednjoj letalnoj dozi dovode do znakova kolinergičkoga trovanja u pilića te do istodobnoga pada aktivnosti kolinesteraza u mozgu i plazmi