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  • Author or Editor: Virág Krízsik x
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Arctodiaptomus spinosus (Daday, 1891) is a characteristic species of the soda pan zooplankton in the Great Hungarian Plain. The biogeographical distribution of the species is interesting, since its range expands from the Pannonian Biogeographic region to the other side of the Carpathians, occurring in saline lakes in Eastern Anatolia, Armenia, Iran and in temporary waters in Ukraine. Our investigations focused on the morphometric characteristics and the COI haplotype diversity of four Hungarian populations in the Kiskunság area. We detected substantial morphological differences between the Böddi-szék population and the rest of the sampling sites, however considerable differences were not observable in the COI haplotypes in the populations. The 20 animals investigated for COI haplotypes belonged to the same haplotype network. Tajima’s D indicated departures from the neutral Wright – Fisher population model and suggested population expansion. The genetic composition of Arctodiaptomus spinosus populations in the Kiskunság area is rather uniform.

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Acta Veterinaria Hungarica
Authors: Á. Klein, Margit Kulcsár, Virág Krízsik, R. Mátics, P. Rudas, J. Török and Gy. Huszenicza

The basic patterns of thyroid hormones [thyroxine (T4) and 3,3',5-triiodothyronine (T3)] and the T4 and T3 responses induced by thyrotropin releasing hormone (TRH) are reported in captive female barn owls (Tyto alba) during the non-breeding period. The main findings of the study, conducted on a total of 10 owls, are as follow: (1) The thyroid gland of barn owl can be stimulated by the classical TRH stimulation test. (2) T3 response was much more pronounced both under cold (around 10°C) and warm (around 20°C) conditions, whereas T4 response ranged so widely that we could not point out any significant change in it. (3) Basal T3 plasma level was significantly (p = 0.036) higher in birds exposed to cold temperature, and they responded to TRH treatment with a lower plasma T3 elevation than the birds kept in a warm chamber. This pattern, however, cannot be explained by increased food intake, but is in agreement with the fact that enhanced T3 level may account for higher avUCP mRNA expression, which results in higher heat production on the cell level. From the results it is concluded that altering T3 plasma level plays a significant role in cold-induced thermoregulation.

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