ON THE ECOLOGY AND SPECIES DIVERSITY OF THE FRESHWATER GASTROPODS OF SPRINGS IN ANDIJAN REGION, UZBEKISTAN

This study examines the species composition, biodiversity, zoogeography, and ecology of freshwater gastropods of 12 springs in Andijan region of Uzbekistan. The study used generally accepted malacological, faunistic, ecological, analytical, and statistical methods. As a result of research in the springs, 14 species of freshwater gastropods belonging to 2 subclasses, 5 families, and 10 genera were recorded. 7 of them are endemic to Central Asia. When indicators of biodiversity of mollusks were analyzed according to the Shannon index, it was found that the highest value was recorded in the springs besides the hills. According to the biotope of distribution and bioecological features, they were divided into cryophilic, phytophilic, pelophilic, and eurybiontic ecological groups. The mollusks, which are common in the springs, were divided into 3 groups according to their faunal similarity. The contribution of the Central Asian and European-Siberian species to the formation of the malacofauna in the springs of the Andijan region was significant.

MACROBENTOS OF VOZHE AND LACHA LAKES

The taxonomic composition of macrozoobenthos in lakes Vozhe and Lacha and in some sections in the Svid and Onega rivers is presented. The dominant complex in the lakes was formed by representatives of chironomids. Two species of oligochaetes and a gastropod were dominant in the rivers. The index of faunal similarity of macrobenthos between the lakes was rather high and amounted to 70%, while the similarity between the river and lake benthos was less than 30%. In the lakes, only two taxonomic groups were recorded, oligochaetes and chironomids that formed the basis of the benthos abundance: 87–93% of the average abundance and 92–95% of the average biomass in the lake. Oligochaetes and mollusks played a significant role in the river communities; in total, they formed 76% of the total abundance and 98% of the biomass. The trophic structure of macrobenthos in the lakes was almost similar, except the appearance of the group of phytodetritophages- filter-feeders in Lake Lacha. Detritophages-swallowers dominated in the river communities. In the previous studies of the lakes, the species richness of benthos both in Lake Vozhe and Lake Lacha was much higher. A decrease in the number of taxonomic groups and decrease in their abundance were observed in Lake Vozhe. At the same time, the role of chironomids in the formation of benthos in the lake was still significant. In general, changes in the taxonomic structure and abundance of benthos in lakes Vozhe and Lacha may be caused by a complex effect of environmental factors and long-term and intra-annual dynamics of dominant (cenose-forming) representatives of the main groups of macrobenthos. The simplification of the structure of the bottom communities, the inclusion of species with wide ecological spectra, the predominance of eurybionts among the dominants, may indicate pollution, eutrophication, and contamination of water bodies. According to the indicator species both lakes may be regarded as mesosaprobic water bodies.

Freshwater gastropod richness patterns along an urbanization gradient in tropical India

Data on the urbanization impact on freshwater biota and ecosystem function are limited from many developing countries despite being recognized as a driver for biodiversity loss. To study these impacts, we analysed the species richness and diversity patterns of freshwater gastropods along a gradient of urbanization in a river system around Pune city, India. We observed a significant reduction in species richness, faunal similarity and an increased proportion of non-native species with increasing urbanization. These impacts were prominent in highly urbanized sites of the rivers suggesting biotic homogenization. Our results underscore the great impacts of urbanization on freshwater biota, highlighting the need for further studies in developing regions.

Mantodea oasis of Palaearctic region: biogeographical analysis of Mantodea in Egypt

Background Egypt forms a home for the highest number of recorded Mantodea species of the Palaearctic Region. The status and ecology of such diversity are far from being completely understood. Main body Through this study, the similarity of Mantodea species composition among Egyptian ecological zones has been examined by using the Sørensen-Dice coefficient, beside the calculation of species richness for each zone. Also, maximum entropy (Maxent) modeling was used to estimate the potential distribution of Mantodea species throughout the country. Three topographical and 19 bioclimatic variables have been used to estimate the current status of all Mantodea species in Egypt. The collected materials of adult mantis have been used to analyze the seasonality of 14 Egyptian common genera. Our results indicated that there was a high faunal similarity between the Western and Eastern deserts, the coastal strip, and the lower Nile valley. The lowest similarity was between Gebel Elba and all other zones. The analysis of habitat suitability of Mantodea in Egypt was fragmentary and focused on different distinct ecological zones. Altitude was the most effective ecological factor that affected Mantodea distribution as a group. Analysis of seasonality data of the common genera of Mantodea indicated that all are found in summer except for Miomantis, Severinia, and Sinaiella. Conclusion Our results can be used as a basis for future studies of the ecology of certain species and conservation of this interesting group in Egypt.

Ecologo-faunistic review of lamellicorn beetles (Coleoptera, Scarabaeoidea) of urbocenosis of Kharkov city (Ukraine)

This article presents a general overview of the superfamily Scarabaeoidea in five parks of Kharkov city and some adjacent agrocenosises. The species composition includes 32 species from four families of Scarabaeoidea. The Scarabaeidae family dominated in biodiversity and abundance (26 species from 16 genera). Six species (Dorcus parallelopipedus, Platyderes caraboides, Anoplotrupes stercorosus, Aphodius melanostictus, Pleurophorus caesus and Onthophagus coenobita) were sporadically registered as common, but in separate urban cenosises the number of species did not exceed one or three. The species composition and abundance of lamellicorn beetles was higher in large parks with only slight recreational disturbance. Here from 13 to 20 species were registered. On lawns in the center and in other districts of the city Scarabaeoidea species met very rarely. In the agrocenosises on the outskirts of Kharkov city – 16 species are noted, almost half of which were registered as common. The faunistic similarity of different urban cenosises was at low to medium levels (an average 0.20–0.47). These indices were slightly higher (0.38–0.67) for areas with lower recreational pressure. The indices of faunal similarity of separate parks and agrocenoses were lower (0.18–0.56, but on average – 0.33). At the level of common species, there was no faunistic similarity. The significance of such differences was due to both the low number of most Lamellicorn species and some of their ecological characteristics. The main differences were observed in the ratio of trophic groups and features of the spatial distribution of the dominant species. Smaller differences were observed on biotopic characteristic of most species. There were no differences in the hygropreference of the scarabeid species. In the parks herpetobiont saprophagous species dominated (mainly coprophagous and dendrophagous). In the agrocenoses, dendrochordobiontic phytophagous species predominated. The peculiarities of the ratio of different ecological groups of Scarabaeoidea in urban and agrocenosises are discussed.

REEF ASSOCIATED MOLLUSCAN FAUNA OF THE SANTA MARTA AREA, CARIBBEAN COAST OF COLOMBIA

A total of 263 molluscan species (201 of them found alive), collected from 1982 to 1989, is reported from seven coral reef localities of the Santa Marta area, Colombia. Species were arranged according to the reef zones in which they were found, their feeding habits and mode of life. Cluster analysis of faunal similarity between reef zones revealed the ocurrence of three molluscan assemblages (settled respectively in shallow environments, reef-slope zones, and sand-coral rubble zones), plus one containing few species and limited toa small zone dominated by lettuce coral (Agaricia tenuifoiia). There are some differences between reef zones in the distribution of species with respect to feeding habits. Vagrant, carnivore gastropods constitute the most diverse group, but filter-feeding bivalves and herbivore gastropods reach high numbers in some zones. Some species were not recorded previously from the Caribbean coast of Colombia.

Biogeographic and faunistic division of the Eurasian Polar Ocean based on distributions of Hydrozoa (Cnidaria)

The hydroid and hydromedusa fauna of Russian Arctic seas, totalling 161 species, has been revised taxonomically and biogeographically. Diversity is highest in the Barents Sea, where 133 species are known to occur. Species composition of Hydrozoa throughout Russian Eurasia is decidedly uniform, with marked similarity among all regional faunistic lists. An assemblage of Arctic ubiquitists, a majority of them boreal-Arctic species, comprise the main element of hydrozoans in all Arctic seas. This faunistic main element is responsible for the faunal uniformity observed from one sea to the next across thousands of kilometres along the northern Eurasian coast. Exceptions occur in marginal regions including western parts of the Barents Sea and south-eastern parts of the Chukchi Sea, where species distribution area contours (named as ‘synperates’) come close together. Based on a biogeographic analysis of faunistic data and species distributions of Hydrozoa, all temperate and cold waters of the Eurasian seas and the Central Polar Basin were referred to a single Arctatlantic biogeographic realm. Biogeographic subdivisions within this realm have rather low hierarchical rank, the result of low endemism, high faunal similarity across the northern seas, and predominance of a North Atlantic fauna in Russian northern seas as far as the easternmost Chukchi Sea.

Sea slugs (Gastropoda: Heterobranchia) from a poorly known area in North-east Brazil: filling gaps in Atlantic distributions

Qualitative samples of ‘opisthobranchs’ were collected from different beaches and estuaries in Ceará State, North-east Brazil. Further species distributions from the literature were used to infer patterns of distribution and to analyse faunal similarity among Atlantic biogeographic areas, Brazilian zones and the Ceará State. A total of 35 new records are reported for the Ceará State, including 19 new records from the North-east Brazilian Shelf (NBS), 12 new from the Brazilian Province and two new records from the South Atlantic. More than half of the species in this area are common between the Caribbean and Brazilian provinces, which demonstrates their capacity for crossing the Amazon–Orinoco barrier. The high percentage of occurrence in the NBS and the South Brazilian Bight, when compared to neighbouring zones, may be attributed to the poor knowledge of the Brazilian ‘opisthobranch’ fauna.