2. This study comprises a comparative study of the ecology and habitat requirements of two new populations in the rivers Beça and Terva (tributaries of the River Tâmega, northern Portugal) with non-Iberian populations.3. Surveys were conducted in 2010/2011 to characterize ecological status and propose possible conservation measures. Both rivers were in good environmental condition, but the River Beça had higher biological, physicochemical and hydromorphological quality.4. Both populations are highly susceptible to extirpation -in particular the River Terva population, given the very low number of specimens found and no sign of recent recruitment. The low number of juveniles and the existence of several threats in both rivers (e.g. fragmentation and loss of habitat caused by the presence of physical obstacles, organic pollution and bank erosion due to fires) imply the need for urgent, effective, conservation measures.5. Southern European M. margaritifera populations have similar ecological and habitat requirements compared with those of northern and central Europe. However, functional populations may endure higher phosphate content, pH and temperature values. As expected they present faster growth rates and reduced life spans.

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the glochidium larvae of freshwater mussels of the family Unionidae need to find suitable hosts to attach themselves and metamorphose into free-living juveniles. the specificity of the host-parasite relationship was investigated for the iberian Unio tumidiformis castro, 1885 by means of experimental infections and also by analyzing naturally infected fish. the process of encapsulation of glochidia was studied using scanning electron microscopy. Unio tumidiformis has proven to be an unusual host-specific unionid mussel, apparently parasitizing only fish of the genus Squalius Bonaparte, 1837. successful encapsulation or complete metamorphosis was observed in five fish taxa: S. aradensis (coelho, Bogutskaya, rodrigues et collares-Pereira), S. caroliterti (Doadrio), S. pyrenaicus (günther), S. torgalensis (coelho, Bogutskaya, rodrigues et collares-Pereira) and S. alburnoides (steindachner) complex (only for the nuclear hybrids with at least one copy of the S. pyrenaicus genome). complete metamorphose was achieved in 6 to 14 days at mean temperatures ranging from 21.8 to 26.1 °c. the current study provides support for cell migration being the main force of cyst formation and shows the influence of potential host's genome in response to the infection process to determine the success of the metamorphosis.

Modern tests of the Mathusian model and its variations have relied almost exclusively on the Wrigley-Schofield demographic data for England, the only available source of annual national data on population stocks for a premodern economy. In this paper, we provide evidence for another such economy, early modern and nineteenth century Portugal. For this, we use a new sample of parish-level annual statistics up to the first modern census of 1864. All six major regions of the country are considered. We combine this information with intermittent census-type data on population stocks to arrive at annual regional and national population stock estimates for this period. Hence we offer a new methodological contribution for the construction of population stocks over the very long run. This methodology can be used in situations in which there is limited availability of local annual gross flows but some intermittent information about stocks is obtainable.

Portugal is half way between countries with the highest and lowest IBD prevalence, but is steeply making the road to the highest-level group. Despite limitations of the proposed methods, assumptions were reasonable and estimates seem to be valid. Feasibility and comparability of this methodology makes it an interesting tool for future studies on IBD epidemiology.