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Identifying populations and establishing the connectivity between neighbouring stocks are central issues for the assessment and management of coastal marine fish species. In this paper, we analysed the population structure of the demersal sciaenid argentine croaker Umbrina canosai, endemic in the warm, temperate southwestern Atantic between southeastern Brazil (SE) and Argentina, by combining two phenotypic techniques: otolith shape analysis and fish growth rate. Three otolith morphotypes were consistently identified, one in the northern latitudinal range in SE, and two in the southern range of the species from southern Brazil to Argentina. Two stocks with differences in growth rate were identified, one with a significantly smaller asymptotic length in the northern range (L∞ = 340.08; k = 0.267; t0 = −2.177) and the second in the southern range (L∞ = 425.08; k = 0.236; t0 = −2.46), where no growth differences were observed between fishes with the two otolith morphotypes. Although genetically U. canosai can be considered to form a single panmictic population, growth and otolith shape indicate that there are two different stocks, one in southeastern Brazil and another in the southern distribution, confirming previous parasitological studies. The difference in otolith morphotypes in the southern range suggests that two subpopulations share the same reproductive grounds, although probably feed in different locations. [ABSTRACT FROM AUTHOR]

Corynosoma australe and C. cetaceum are the most frequently reported acanthocephalans in fish from the Argentine Sea, particularly in central and northern areas. Their definitive hosts are otariids and odontocete cetaceans, respectively. The low specificity of these larvae, in combination with high infective capability and long survival periods in fish, make them potentially good biological markers for stocks and other biological features of their fish hosts. In order to determine the distribution patterns of these species and their determining factors, a large dataset composed by newly collected fish samples, published and unpublished data from previous studies by the authors in the region were analysed in relation to host and environmental variables. The complete dataset comprised a total of 5084 fish, belonging to 29 species distributed in 21 families and 9 orders. Host size and trophic habits arose as the main determinants of abundance for both species of Corynosoma, showing higher abundances on larger fish and on higher trophic levels, as it is usual for trophically transmitted parasites. Biogeographic province and depth (indirectly representing the temperature of water) were the main drivers of the spatial distribution, displaying a latitudinal pattern associated to the temperature clines created by the interaction of Malvinas and Brazil currents, determining a decrease in abundance southwards and towards the deeper areas. No patterns were found regarding the distribution of definitive hosts. The knowledge of these distribution patterns of Corynosoma spp. in fish at regional scale, as well as of their causes, provides useful information to design management and conservation policies thus contributing to maintain the full and sustainable productivity of fisheries. [ABSTRACT FROM AUTHOR]

Background: Since its discovery, oral anticoagulants (OA) have been increasingly studied and used to treat different diseases. However, OA may cause adverse drug interactions that bring risks for patients. Objective: To identify the emergency room doctors' level of knowledge about OA and their drug-related or non-drug-related interactions, and to verify if emergency room doctors are prepared to integrate their theoretical knowledge and the routine of the emergency room. Method: A questionnaire was administered to 100 emergency room doctors working at two public hospitals and three private hospitals in Curitiba, Brazil. The objective of the questionnaire was to find out: if emergency room doctors asked patients about the use of OA, which OA doctors were familiar with, which control exam would be appropriate, what doctors knew about the synergism with OA, how complications were managed, and if doctors were interested in knowing more about OA. Results: Sixty percent of the doctors reported to ask patients about the use of OA, 81% had insufficient knowledge regarding the synergism between some substances and OA, 15% were unaware of which exams are used to follow up anticoagulated patients, 50.7% did not know the commercial names of OA, 4% were unaware of OA antidotes, and 92% revealed interest in improving their knowledge about OA. Conclusion: The number of emergency room doctors who were familiar with OA is low, as well as the number of those who know how to manage anticoagulated patients. The percentage of doctors who did not ask patients about the use of OA and who were unaware of the principles of drug synergism is high, and most of them were interested in improving their knowledge about anticoagulants. [ABSTRACT FROM AUTHOR]

• Fish age and size have a strong influence on the structure of parasite assemblages. • Similarity in parasite assemblages decreases as differences in host size increase. • Parasite communities in younger specimens are more heterogeneous and stochastic. • Ontogenetic change in parasite loads is enhanced by age-related asynchronic migrations. • Parasite tags must be used cautiously if asynchronous and divergent migrations occur. Several species of marine fishes perform seasonal migrations alternating foraging and spawning habitats during their life cycles. The knowledge of these movements is essential to define their population structure which is, in turn, necessary for a sustainable management of any fishery resource. Parasite tags have been extensively applied for stock identification and host migration assessment, proving to be excellent markers. However, ontogenetic changes in the structure of parasite assemblages must be considered since, due to ontogenetic cumulative patterns, differences between host length can lead to a misinterpretation of the patterns in this type of studies. The aim of this work was to evaluate the asynchronous migrations of the Argentine croaker Umbrina canosai , a demersal fish that inhabits coastal waters of Brazil, Uruguay and Argentina, as a cause of ontogenetic differences in parasite loads, considering its impact in the interpretation of migratory patterns when parasite assemblages are used as biological tags. A total of 254 specimens distributed into 8 samples (3 newly collected and 5 from previous study) with differences in mean length were examined for their metazoan parasites. Only long-lived parasites were used for comparisons between samples. A strong influence of fish length on the structure and composition of the parasite assemblages was observed across samples. Indeed, a clear pattern of similarity decay between parasite communities was evident as the differences in host length increased, demonstrating the importance of ontogenetic changes in the structure of parasites assemblages. On the other hand, differences in parasite assemblages were, most noticeably observed in young fish, indicating probable variations in migratory routes, distance traveled and/or latitude reached, depending on environmental conditions and age. Consequently, differences among fish length classes must be considered when using parasite tags for those resources with temporally and spatially variable migratory patterns, especially when different cohorts are compared. [ABSTRACT FROM AUTHOR]