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The study was performed in five fourth-order tributaries of the Bystrzyca Lubelska River (Eastern Poland, Lublin Upland), differing in the degree of river-bed transformation and level of pollution. Hydro-morphological methods (descriptive method by Ilnicki and Lewandowski - IL, and index method by Oglecki and Pawlat - OP) and biological indices based on the composition of zoobenthos (Diversity - D, and index based on proportions between the density of Oligochaeta and Chironomidae - O/Ch) permitted distinguishing of four classes, from II to V. The distinguishing of only two quality classes (III and IV) was possible by means of physical-chemical methods and by benthic index BMWP_PL. Those two methods seem to show the lowest sensitivity to the spatial variability of the environment quality. The BMWP_PL index was the least sensitive to year-to-year environmental changes, and O/Ch was the most sensitive. Relatively high conformity was obtained between hydro-morphological assessments performed by means of the OP and IL methods. Results obtained by means of these tools weakly corresponded with the physical-chemical assessments. The latter assessments were the most similar to those obtained by means of the BMWP_PL (degree of similarity = 57%) and D (47%) indices, and considerably less in the case of O/Ch (36%). The BMWP_PL and D indices better corresponded with the results of the hydro-morphological assessment performed by means of the IL method than with those performed by means of the OP method while D index showed a reverse pattern. The O/CH index proved useful for the assessment of the degree of organic pollution of the river’s water, but not the sediments.

Fish may affect macrobenthic communities through trophic interactions and modification of habitat conditions. We compared the density, diversity and taxonomic composition of larval chironomids under low vs high fish impact, created by stocking semi-natural ponds with either young/small common carp Cyprinus carpio at low biomass densities or with high biomass densities of older/large common carp, supplemented by other cyprinids and predatory fish species. Over the study season, May–August, total chironomid abundance was considerably lower in ponds with high fish biomass than in low fish biomass ponds. In July–August larval densities declined significantly, irrespective of the fish status of the ponds. The composition of larval communities diverged between ponds with different fish status. Chironomus riparius and C. plumosus accounted for most of the observed dissimilarity. C. plumosus densities were not affected by the fish status of the pond, constituting on average >38 % of chironomid specimens in both types of ponds. C. riparius was abundant in ponds with low fish biomass (on average 30 %), but rare in ponds with high fish biomass (4 %). Other common taxa were Glyptotendipes pallens (15 % and 13 %, respectively) and Procladius sp. (14 % in ponds with low fish impact). Canonical correspondence analysis showed that fish biomass was more important in determining chironomid community composition than environmental variables indicative of pond eutrophication (total N, P, chlorophyll a and conductivity). Despite adverse effects on total abundance, chironomid diversity was higher under apparently stronger trophic pressure by fish. Fish may have relieved some chironomid species from invertebrate predation and competition with dominant Chironomus larvae. Other important drivers of chironomid assemblage and diversity patterns may include species-specific feeding modes and prey size selectivity of fish, the ability of chironomid larvae to attain size- and depth-refuge from small fish but not larger fish, and differential vulnerability of free-living and tube-dwelling larvae relative to ontogenetic niche shifts of fish.

In October 2003, the small-sized river Galezowka (Lublin Upland) was channelized on its prevailing length, according to the assumptions of so-called “natural channelization”, i.e. among others, without straightening the river channel and leaving some river sections untouched. The surveys were carried out in 2003–2004, before and after the channel works, at two 100 m long sections: the disturbed site, and one placed upstream untouched reference site. Physical and chemical analysis suggested slightly better water quality at the reference site. Both density and biomass of the zoobenthos at the two sites were predominated by chironomid larvae and Tubificidae. The channel works did influence strongly taxa richness, dominance structure, density and biomass of the fauna. This was evident especially one month after the channel works. Values of Shannon-Wiener diversity index were higher at the disturbed site, however. The seasonal changes in density and biomass at the disturbed site exhibited a different pattern than at reference one. After one month after the channel works, the fauna of the two sections studied exhibited rather high level of faunistic similarity, suggesting high rate of animal communities reviving.

Up to now in Tunisia, freshwater Hirudinida are represented by two mainly haematophagous families: Hirudinidae and Glossiphonidae, and a predatory one: the family Erpobdellidae. The present study provides new information on the diversity and taxonomy of erpobdellid leeches. Identification was based, in addition to morphological data, on the length of sperm ducts and the lengths of ovisacs in relation to the neurosomite (ns) and on the shape and size of the male atrium. Five taxons are found. Two subspecies are reported for the first time in the country: Dina punctata punctata Johansson, 1927 and Dina punctata maroccana Nesemann and Neubert, 1994. Tunisian populations of two species, Erpobdella testacea (Savigny, 1820) and Trocheta africana Nesemann and Neubert, 1994, are described, with records of new localities. The new Trocheta tunisiana n. sp. is discovered and described in detail. Trocheta species live in springs in elevated areas while Erpobdella seem to prefer low altitude reservoirs. A comprehensive comparison of the three genera is presented. The disparity between the actual systematics and phylogeny is discussed. This study gives also a detailed distribution of the five species in the north of Tunisia with notes on ecological preference of the genus Dina. Finally a key for the determination of freshwater erpobdellid species from Tunisia is proposed.

A new species of fish leech from Poland, Piscicola burresoni n. sp. (Piscicolidae), is described. The leech was found in 2007 on stones and on pike (Esox lucius L.) and chub (Leuciscus cephalus L.) in the Łyna River, Poland. The leech is small, relatively flattened, with a prominent coarctation between the trachelosome and urosome. The pigmentation is unique to the new species and it has 14 annuli with gonopores separated by 4 annuli. The receptaculum seminis consists of an elliptical aperture located at a distance of 3 annuli behind the female gonopore. The copulatory area on the clitellum is characteristic in the shape of a parallel ellipse. The vector tissue is in the form of a transverse plate below the oviduct outlet. For a complete description of the external morphology, a geometric–mathematical model of the leech body form was used.

Epidemiological studies point out steady increase of the incidence of cancer disease in Poland and all over the world. Neoplasms are associated with blood coagulation disorders very frequently. The investigations concentrate on searching for the substance producing malignant cells and causing activation of blood coagulation in neoplasm disease patients. Gordon and co-workers were the first who published results of their investigation in searching for such a substance in 1975. It was isolated from the rabbit's neoplasm type V2 Ca and then characterized and named as cancer procoagulant (CP). Cancer procoagulant is responsible for blood coagulation disorders in neoplasm disease patients, incorrect metabolism of fibrin and its concentration around malignant tissues. This enzyme (in vitro) is a direct activator of the factor X, without contribution of factor VII or any other cofactors. CF differs in physical, chemical and enzymatic activity from others procoagulants. The main aim of the paper is a review of the literature for structure, chemical characteristic, occurrence and clinical relevance of the cancer procoagulant (CP) and its clinical use in current oncological diagnostics.

Up to now in Tunisia, freshwater Hirudinida are represented by two mainly haematophagous families: Hirudinidae and Glossiphonidae, and a predatory one: the family Erpobdellidae. The present study provides new information on the diversity and taxonomy of erpobdellid leeches. Identification was based, in addition to morphological data, on the length of sperm ducts and the lengths of ovisacs in relation to the neurosomite (ns) and on the shape and size of the male atrium. Five taxons are found. Two subspecies are reported for the first time in the country: Dina punctata punctata Johansson, 1927 and Dina punctata maroccana Nesemann and Neubert, 1994. Tunisian populations of two species, Erpobdella testacea (Savigny, 1820) and Trocheta africana Nesemann and Neubert, 1994, are described, with records of new localities. The new Trocheta tunisiana n. sp. is discovered and described in detail. Trocheta species live in springs in elevated areas while Erpobdella seem to prefer low altitude reservoirs. A comprehensive comparison of the three genera is presented. The disparity between the actual systematics and phylogeny is discussed. This study gives also a detailed distribution of the five species in the north of Tunisia with notes on ecological preference of the genus Dina. Finally a key for the determination of freshwater erpobdellid species from Tunisia is proposed.