Małgorzata Raczyńska

LEECH COMMUNITIES IN THE UPPER REACHES OF THE STEPNICA RIVER (NW POLAND)

The paper describes taxonomic composition of leeches (Hirudinea) in the strongly anthropogenically altered upper reaches of the Stepnica River in Western Pomerania. The numbers of respective species of the Hirudinea were analyzed in the context of such environmental factors as: instantaneous flow, dissolved oxygen content, and calcium content. It was noted that most leech species inhabited the headstream, and factors deterrent to their occurrence included the presence of hydrogen sulfate and siltation.

LOADING THE WATERS OF THE RIVER GWDA WITH BIOGENIC SUBSTANCES WITHIN THE ADMINISTRATIVE BOUNDARIES OF THE TOWN OF PIŁA (NORTH-WEST POLAND)

The results of hydrochemical tests of the Gwdy river in the area of the town of Piła are presented in this study. The catchment area of the Gwda river comprises the area of 4942.8 km2. The surface of catchment area is covered with forest in 43.1%, arable land constitutes 36.5%, and grassland 7.2%. The Gwda river is a right-bank tributary of the Noteć River of IV order. Water samplings were collected in 2009 from three measurement and control points located between 13 and 24 kilometre of the course of the river. During the tests thermal and oxygen conditions were marked and biogenic substances (nitrate acid, ammonia nitrogen, nitrite nitrogen, total nitrogen, total phosphorus and mineral phosphorus). Concentrations of most of the indicators examined qualified the waters of Gwda to the waters of good quality. The indicator whose concentrations exceeded the limit values for the waters of quality was general phosphorus.

BOTTOM SEDIMENTS AS AN ELEMENT OF THE KRĄPIEL RIVER ECOSYSTEM

Research on the structure of sediments was carried out in 2015 in the river Krąpiel and its tributaries. The main objectives of this study were to classify the types of sediments with grain size analyzing according three different criteria, as well as influence of the substrate on the abundance and diversity of macrobenthic organisms, and to determine the quality of the ground for natural breeding of salmonids. It was found that according to Polish standards, bottom sediments of the Krąpiel river and its tributaries belong to the coarse – gravel type or sandy – gravel type, whereas according to the method used in Anglo-Saxon countries – these are sandy sediments. It was also shown that the grain size of bottom sediments of the Krąpiel river and its tributaries determine friendly living environment for macroinvertebrates and for breeding salmonids.

STABILITY OF MACROZOOBENTIC COMMUNITIES IN RIVER MAŁA INA, A LEFT-BANK TRIBUTARY OF RIVER INA (NW POLAND)

The study results presented include an analysis of the biological material collected in May 2007 and 2012 from the Mała Ina river located in the Ina River basin. These served as the basis for determining the taxonomic structure of macrobenthos. The river studied varied with regard to the qualitative and quantitative structures of individual taxa, and the biodiversity in the streams was very low. Despite a significant difference in the number of individuals making up the benthos in the analyzed periods, in terms of quality, this group consisted of almost the same in terms of taxonomic organisms.

STAŁOŚĆ FAUNY MAKROBENTOSOWEJ NA PRZYKŁADZIE RZEKI MAŁA INA LEWOBRZEŻNEGO DOPŁYWU INY (POMORZE ZACHODNIE)

The study results presented include an analysis of the biological material collected in May 2007 and 2012 from the Mała Ina river located in the Ina River basin. These served as the basis for determining the taxonomic structure of macrobenthos. The river studied varied with regard to the qualitative and quantitative structures of individual taxa, and the biodiversity in the streams was very low. Despite a significant difference in the number of individuals making up the benthos in the analyzed periods, in terms of quality, this group consisted of almost the same in terms of taxonomic organisms.

Stałość fauny makrobentosowej na przykładzie rzeki Mała Ina lewobrzeżnego dopływu Iny (Pomorze Zachodnie)

The study results presented include an analysis of the biological material collected in May 2007 and 2012 from the Mała Ina river located in the Ina River basin. These served as the basis for determining the taxonomic structure of macrobenthos. The river studied varied with regard to the qualitative and quantitative structures of individual taxa, and the biodiversity in the streams was very low. Despite a significant difference in the number of individuals making up the benthos in the analyzed periods, in terms of quality, this group consisted of almost the same in terms of taxonomic organisms.

BIOLOGICAL CHARACTERIZATION OF NEOMYSIS INTEGER (LEACH, 1815) FROM THE POMERANIAN BAY IN 2006 -2007

The aim of the study was to determine the biological characters typical of Neomysis integer, to investigate and update issues of its biology, ecology, and distribution in the southwestern Baltic Sea, and to compare biological properties of N. integer collected during eight study seasons in 2006–2007 in the region from Świnoujście to Darlowo. No link was established between N. integer size and sample collection site. The population attained sizes within the range of 2.64 to 18.84 mm. The size at which females achieved sexual maturity varied seasonally. A mean of 34 eggs was noted in the marsupium. The mean wet weight of N. integer was 0.011 g. Three generations were confirmed at most of the study sites .

MOLLUSC SPECIES PROTECTED IN POLAND AND THREATENED IN EUROPE RECORDED IN STEPNICA RIVER (NW POLAND)

In the course of the study two bivalve species protected in Poland were found in the river Stepnica: Sphaerium solidum and Sphaerium rivicola. Moreover, the study material collected from the river contained gastropod and bivalve specimens representing the following species from the IUCN Red List of Threatened Species: Theodoxus fluviatilis , Pisidium henslowanum, Pisidium casertanum and Pisidium pseudosphaerium.

COMPARATIVE MORPHOLOGICAL ANALYSIS OF NEOMYSIS INTEGER (LEACH, 1815) IN 2006-2007 PERIOD

This paper presents the results of a detailed comparative description of the morphological characters of N. integer obtained during eight research seasons in 2006–2007 period from the region stretching from Świnoujście to Darlowo. An attempt was made to assess the suitability of the studied characters for establishing to which populations individuals belong, to identify secondary sex traits and to detect differences in the body shape of these shrimp-like crustaceans. Most of the measurable characters in all of the samples discrimination analysis indicated the characters which differentiated the compared groups were telson length, lower abdomen width, exopodite uropod length, cephalothorax width below the carapace, cephalothorax width above the carapace and the height of fourth and fifth abdominal segment connections.