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The third record of Cinara tujafilina occurrence in Poland is given. The population dynamics of the species is presented.
The bionomy and ecology of Cinara cupressi on Thuja occidentalis was studied under insectary and controlled conditions. The number of generations per year was determined, as well as the lifespan of a generation, fecundity of the females and demographic characteristics of the population.
Background. Ghrelin, a newly discovered hormone is involved mainly in the regulation of body energy homeostasis. It has also been proved that ghrelin affects many other processes including the control of the hypothalamo-pituitary-gonadal axis in vertebrates. Ghrelin interacts also with other peptides and neurotransmitters, which are involved in gonadotropin release, such as endogenous opioid peptides. The aim of the experiment was to compare the effects of ghrelin and naltrexone, an opioid antagonist, on LH secretion by pituitary cells of mature female and male common carp, Cyprinus carpio L. Materials and methods. In the in vitro experiment the time-dependent (10 and 24 h) action of ghrelin (10-7 or 10-6 M) and naltrexone at 10-6 M added alone or in combination on LH secretion by enzymatically dispersed pituitary cells of mature female and male carp (Cyprinus carpio L.) was studied. Results. Ghrelin alone at a dose of 10-6 M stimulated LH secretion after 10 h of female- but not male-derived cell incubations. Ghrelin at 10-7 M had no effect on LH secretion from either female or male cells. Naltrexone alone stimulated LH secretion only after 24 h of female cell culture. In male cells no significant changes in LH secretion in response to naltrexone alone were found after 10 or 24 h incubation period. Combined treatment (ghrelin 10-7 or 10-6 M and naltrexone) stimulated LH secretion in female and male cell incubations at 10 and 24 h: LH levels were significantly higher in comparison to control, to ghrelin alone (in cells of both sexes) and to naltrexone alone (in male cells only). Conclusion. The results suggest that opioids and ghrelin may control LH secretion in carp acting synergistically, probably through the same receptor type. The concept of opioid and ghrelin interaction in the gonadal steroid feedback on LH release is also discussed.
The aim of this study was to describe the ichthyofauna composition of the Goczałkowice Dam Reservoir based on records in fisheries logs of commercial catches conducted in this basin over a 16-year period (1986-2001). The results indicate that the Goczałkowice Reservoir was managed appropriately during this period. The dominant species in the reservoir was bream at 49.74% of the overall biomass of all the fish caught. The second most common fish was a mix of small fish (31.62%). Evidence of the rational management of this basin is that 17% of the ichthyofauna are predacious fish, with pikeperch comprising 56% of all the predacious fish caught.
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