2009 Issue №7

The article analyses the seasonal dynamics of zebra mussel (Dreissena polymorpha Pallas), larva length composition and juvenile recruitment in perennial natural colonies in the Prybrezhny Querry (the Kaliningrad region). In 2002, zebra mussel larvae were found in plankton from the second part of July till the end of August. The peaks of abundance were registered in the middle of July and in the beginning of August. The larvae accounted for 33% of the total zooplankton abundance. The size of larvae varied from 100 to 375 μm. The beginning of the juvenile settlement was observed in July. Colony mud accumulation is considered having a negative effect on successful settlement and survival of juveniles.

The article describes the quantitative content dynamics of the hydrocortisone steroid hormone in different organs and tissues in the course of the common octopus ontogenesis. The author detects general patterns of its quantitative distribution in the octopus organism and formulates a hypothesis on the functional significance of hydrocortisone in the examined tissues of mollusks.
Hydrocortisone level is one of the most important organizers of general adaptation syndrome in the organisms of vertebrates under different forms of stress. It may be also used as an indicator of organism state of invertebrate hydrobionts in biotesting and bioindication of water biocenoses.

The article presents the preliminary results concerning the quantitative content of nitrogen-fixing, cellulose-eliminating microorganisms and microorganisms using the mineral forms of nitrogen and microscopic fungi in Kaliningrad soils under different environmental conditions.

The analysis of Ch. balatonicus population cytogenetic structure shows that all seven chromosomal arms are polymorphous, the most polymorhous one is arm D, which was presented by four chromosome band sequences. Standard sequences as well as their zygotic and genome combinations prevail in the population. The presence of balD5, balD7 sequences in the population
karyofund earlier recorded only in eastern populations and three new inversion band sequences (balB8, balF8, bal(EF)X) characterizes the cytogenetic structure as partly unique, formed under specific conditions of brackish water reservoir.

The article presents regress equations of age-related average height changes by growth classes and of general wood pulp by average height and density of the black saxaul forest stand, derived as a result of statistical modelling.

The article reviews the research on the influence of abiotic factors on plant antioxidant pool formation conducted at IKSUR.