Joanna Pakulnicka

The formation of water beetle fauna in anthropogenic water bodies

The formation of water beetle fauna in anthropogenic water bodies Studies on the fauna of water beetles inhabiting anthropogenic water bodies were conducted on 44 clay-pit and gravel-pit ponds. A total of 125 water beetle species were identified. The dominant species were Scarodytes halensis and Laccobius minutus, representing the argillophilous component. Eurytopic, lake and riverine, and peatland species were also identified. Among the environmental factors determining the diversity of the water beetle fauna in particular types of habitats, the most significant role was played by the substratum and succession stage.

Coexistence of Placobdella costata (Fr. Müller, 1846) (Hirudinida: Glossiphoniidae) and mud turtle Emys orbicularis

Emys orbicularis is receding from Europe, mainly due to anthropogenic habitat changes. Its parasite, Placobdella costata, is widely distributed within both the former and the present distribution range of the host. Though closely associated with the mud turtle, it may have other hosts (birds, amphibians, reptiles). Its reproductive period coincides with that of its host’s migration to the breeding grounds, thus facilitating dispersal of the parasite. Based on literature data we have analyzed the geographic spread of P. costata and mud turtle to observe the possible overlap of their habitats. Observations on the population of mud turtle and the associated leech species (P. costata) were carried out in eastern Poland — Podlasie Lowland. The studies were conducted in spring and summer in 1986–1993. The leeches were collected from the turtles caught in the water and on land. Observations showed that most leeches were found on turtles inhabiting the lake or moving to a breeding area. The greatest intensity of invasion was observed in June and July and that most leeches were observed in female E. orbicularis characterized by greater length of the carapace and weight, compared with males and juvenile individuals.

The Effect of Dredging of a Small Lowland River on Aquatic Heteroptera

Rehabilitation of river beds is sometimes necessary, particularly when a substantial amount of bottom sediment causes unnaturally slow water flow. However, it is difficult to predict whether such procedures will negatively affect biodiversity and species composition of organisms inhabiting these sites. The effects of such procedures were analysed in the Krąpiel river in northwestern Poland. It was postulated that dredging would not reduce Heteroptera diversity, but would alter the habitat significantly and create lotic habitats for rheophilous species. It was also postulated that conditions would become less favourable for taxa preferring a bottom with accumulated mud and abundant vegetation. According to our results, dredging did not significantly affect species diversity of Heteroptera, but did cause an increase in abundances of several species. Dredging increased the number of available habitats, which were mainly inhabited by abundant pioneer species. Aquarius najas, Aphelocheirus aestivalis, Plea minutissima, Sigara falleni, Notonecta glauca, Iliocoris cimicoides and Gerridae were most successful in recolonizing the sites after dredging. CCA showed that detritus and the effects of dredging were crucial to the distribution patterns of heteropteran species in this river.

The effect of hydrological connectivity on water beetles fauna in water bodies within the floodplain of a lowland river (Neman river, Belarus)

The middle course of the Neman River is the habitat of 120 water beetle species. Water beetles were most abundant in the Neman River, its major tributaries and oxbow lakes. They consisted of four synecological groups: rheobiontic and rheophilic organisms, type “a” and “b” stagnobionts. The diverse types of aquatic environments constitute faunal centers which, in addition to the specific and dominant Coleopteran populations, also feature migrational elements. The presence of close relations between the fauna of different environments indicates that they form a single, faunistically integrated hydrological system.

Relations Between the Structure of Benthic Macro-Invertebrates and the Composition of Adult Water Beetle Diets from the Dytiscidae Family.

ABSTRACT This paper investigates the relations between the diet structure of predaceous adult water beetles from the Dytiscidae family and the structure of macrofauna inhabiting the same environments. The field studies were carried out from April until September in 2012 and 2013 in 1-mo intervals. In total, >1,000 water beetles and 5,115 benthic macro-invertebrates were collected during the whole period of the study. Subsequently, 784 specimens of adult water beetles (70.6% out of the total sampled) with benthic macro-invertebrates found in their proventriculi, were subject to analysis. The predators were divided into three categories depending on their body size: small beetles (2.3–5.0 mm), medium-sized beetles (13–15 mm), and large beetles (27–37mm). All adult Dytiscidae consumed primarily Ephemeroptera and Chironomidae larvae. Although Asellidae were numerically dominant inhabitants of the sites, the adult water beetles did not feed on them. The analysis of feeding relations between predators and their prey revealed that abundance of Ephemeroptera, Chironomidae, and larval Dytiscidae between the environment and the diet of adult Dytiscidae were strongly correlated.

Piscicola siddalli n. sp., a Leech Species from the United Kingdom (Clitellata: Hirudinida: Piscicolidae)

Abstract A new species of fish leech from England, Piscicola siddalli n. sp. (Piscicolidae), was collected in 2006 on stones and on grayling (Thymmallus thymmallus L.) in the River Ure, North Yorkshire, Great Britain. The leech is 4(12) annulate; gonopores are separated by four annuli. The male gonopore is much larger than the female gonopore. Seminal receptacle consists of a round aperture, located at a distance of 3 annuli behind the female gonopore. Copulatory area on the clitellum is in the form of a circle. Vector tissue has the form of a circular plate, below the oviduct opening.

The influence of environmental factors on water mite assemblages (Acari, Hydrachnidia) in a small lowland river: an analysis at different levels of organization of the environment

Research on the ecology of water mites in flowing water has focused mainly on analysis of factors directly affecting these organisms in the aquatic environment. The hypothesis of this study was that apart from factors acting within the aquatic environment, the formation of Hydrachnidia communities in lotic ecosystems may also be affected by factors acting in the terrestrial environment. The analysis was made at three different levels of organization of the environment: (1) landscape level (sub-catchments, terrestrial environment), (2) macrohabitat level (sampling sites, aquatic environment) and (3) mesohabitat level (sampling sub-sites, aquatic environment). Some correlation was noted between certain species and some sub-catchment parameters. This may indicate a link between some landscape features (terrestrial environment) and the formation of water mite assemblages in the river. The low percentage for physicochemical parameters together in explaining the variance in occurrence of species, very low correlations between species and physicochemical parameters and the discrepancy in the grouping of sites in the case of faunal data and data on the physicochemical indicates that physicochemical factors had little influence on water mites. Taking into account all three levels of organization of the environment analyzed, we can say that at the landscape level we can find only indirect relationships between environmental factors and the fauna inhabiting the aquatic environment; at the macrohabitat level the description of Hydrachnidia is more precise but still of a general nature. Only analysis at the mesohabitat level fully explains the specific character of Hydrachnidia assemblages.

Are beetles good indicators of insect diversity in freshwater lakes

Abstract The study verifies the usefulness of aquatic beetles as an indicator of biodiversity of a simple ecological system. Detailed analyses were carried out at the elementary level for the purpose of determining the significance of correlations between the biodiversity of Coleoptera and other groups of aquatic insects in single samples. The relation of selected taxa to selected habitats of the lake Wukśniki (north-eastern Poland) was also investigated. Moreover, the possibility of application of biodiversity surrogates, i.e. higher taxonomic units (genera and orders), in the determination of biodiversity was examined. A significant high correlation was determined between Coleoptera and the total remaining taxa (RR - Remaining Richness) in samples collected in the entire lake. The correlation has the highest value at the species level. The complementarity analysis reveals that the percentage contribution of Coleoptera in the overall biodiversity of the lake is similarly high at the species and genus level, and substantially lower at the family level. In accordance with the hypothesis, aquatic beetles can be used as indicators of the overall biodiversity of insects in the ecosystem of a mesotrophic lake. Biodiversity surrogates, i.e. higher taxonomic units (genera and families), can be applied instead of the species level.

Environmental factors associated with biodiversity and the occurrence of rare, threatened, thermophilous species of aquatic beetles in the anthropogenic ponds of the Masurian Lake District

This paper presents the results of an analysis of species richness (expressed as number of species), biodiversity (the H′ index) and synecological structure of communities of aquatic beetles living in clay and gravel pits. It evaluates the analyzed habitats in terms of the influence of water physical and chemical parameters on the characteristics of beetle assemblages. The assessment of beetle communities was performed from the point of view of ecology and nature conservation. The analyzed physical and chemical parameters of water as well as the presence of certain species, mainly rheophiles, indicate very weak eutrophication of the ponds. The parameters which most significantly distinguish gravel pits from clay pits are specific conductivity, HCO3−, SO42− and Cl–. The PCA analysis, however, suggests that the abundance and species richness as well as the biodiversity of beetles living in the analyzed ponds were most closely correlated with temperature and with NH4-N, total N and the BOD5 of water. The analyzed ponds proved to be very attractive habitats populated by numerous species, including rare, threatened (listed in the Polish Red Book of Species) and termophilous ones, or organisms valuable to Polish wildlife for other reasons. They include two species rare in Poland—Hydrochus ignicollis and Ochthebius hungaricus, one species fully protected in Poland—Hydrophilus aterrimus (VU), as well as Haliplus fulvicollis (VU) and Gyrinus caspius (EN). The findings are important for the preservation of biodiversity, both locally and on a scale surpassing the region, a conclusion which highlights the value of anthropogenic ponds such as clay pits and gravel pits, in the ecological landscape and implies that they deserve an adequate protection in order to sustain their function.

Occurrence of the medicinal leech (Hirudo medicinalis) in birds' nests

Occurrence and breeding of Hirudo medicinalis were recorded in birds’ nests in the fishing ponds and water bodies used extensively by anglers in south-eastern Poland, in 4 of 11 studied bird species (Circus aeruginosus, Fulica atra, Cygnus olor, Chroicocephalus ridibundus). Factors important for the distribution and density of this leech were: nest height, pH of the water and oxygen concentration in the water inside the nests, the body-length of the nesting birds. Our data show that (1) H. medicinalis chooses nests as habitats that are safe in water bodies rich in predators (particularly fish) and provide stable feeding conditions; (2) fishing ponds and other water bodies used extensively by anglers in a landscape modified by human pressure can be an important secondary habitat for the medicinal leech. As the nesting activity of some aquatic birds apparently favors the occurrence of H. medicinalis, active protection of aquatic birds and creating sites appropriate for their breeding may be an indirect way for the conservation of the leech in such areas.