Fish feeding guilds along a gradient of bay biotopes and coral reef depth zones

The study of fish feeding guild structure is a useful method to compare fish communities of complex marine ecosystems. Guild structure was determined in four coral reef depth zones, viz. the fringing reef at depths of 2, 5, 10, and 15 m, as well as in seven shallow-water biotopes within a single bay, viz. notches in fossil reef rock, mangroves, fossil reef boulders, seagrass beds, algal beds at a depth of 2 m, algal beds at a depth of 5 m, and the channel. The study was done in an inland bay on the Caribbean island of Curaçao, using a visual census technique. Total fish densities within the different feeding guilds varied considerably between the biotopes, and were generally higher in the reef biotopes and on the boulders than in the remaining bay biotopes. Cluster analysis revealed that the greatest dissimilarity in guild structures in terms of fish densities was that between the algal beds and all other biotopes, followed by that between the reef depth zones and other bay biotopes (notches, mangroves, seagrass beds, channel). The species composition of the guilds also differed considerably among the various biotopes. Species richness within the various guilds showed much smaller differences between the biotopes, but was generally somewhat higher in the reef biotopes. Cluster analysis of guild structures in terms of species richness revealed little dissimilarity among the various biotopes. The coral reef was dominated by omnivores and zooplanktivores, whereas the bay was dominated by zoobenthivores and herbivores. Differences in guild structure between the bay and the adjacent reef indicate differences in food availability.     

Long-term dynamics of population density and species composition of pasture ixodid ticks (Parasitiformes,Ixodidae) in anthropogenic and natural areas

Long-term monitoring of population density and species composition of ixodid ticks inhabiting the territory of Tomsk and its outskirts has demonstrated that at least two species (Ixodes persulcatus and I. pavlovskyi) simultaneously inhabit all the biotopes examined. It was found that the fraction of I. pavlovskyi increased in biotopes adjacent to city buildings. I. persulcatus dominated in natural control biotopes, whereas I. pavlovskyi were found in these biotopes as solitary specimens. It was demonstrated that during 15 years of observation (1996–2011), the population density of ticks in the outskirts significantly increased. The combination of ecological and chemical methods of tick control in limited territories can result in a noticeable decrease of tick population density. Two tick species non-typical of the region (Dermacentor reticulatus and Haemaphysalis concinna) were revealed in one biotope.     

Assemblages of surface-dwelling Collembolans in Moscow Province. 1. Structure and dynamics of meadow and forest complexes

Data on the species composition, structure, and seasonal changes in the dynamic density of surfaceactive Collembola communities in meadows and forests of Moscow Province are provided. A total of 27 epigeic species were recorded from May to October in four biotopes (18–24 in each biotope) using pitfall traps. All of the communities studied consist of 1–2 dominant species, several subdominants, and 11–19 rare species, with the prevalence of Entomobryomorpha and Symphypleona. The springtail communities in the studied forest and meadow biotopes are very similar in species composition but differ in the relative abundance of individual species. The total dynamic density of epigeic species was shown to vary during the season, being significantly dependent on the type of biotope and the time of survey. The maximum density was recorded at the beginning of the active season (May–June); the minimum density was observed in August.     

Phytogeography of upwelling areas in the Arabian Sea

Aim The identification of the marine plant communities of two islands from different upwelling areas of the Arabian Sea, with a similar diversity in biotopes. A comparison of the species composition of these macroalgal communities and their biogeographical affinities within the Indian Ocean should give insight into the biogeographical position of the Arabian Sea within the larger Indian Ocean. The incorporation of environmental parameters in the analysis is instructive in understanding their importance in shaping the diverse marine assemblages of the Arabian Sea. Location Arabian Sea: (1) the Socotra Archipelago (Yemen; 12.47° N, 53.87° E) in the Somali upwelling area, (2) Masirah Island (Oman; 20.42° N, 58.79° E) in the upwelling area of the southern Arabian Peninsula. Methods The marine flora of different biotopes around both islands were examined by means of qualitative assessments. Ordination analysis [detrended correspondence analysis (DCA)] was used to identify the different plant communities and to correlate these with environmental parameters. The species composition of the identified communities were compared (tripartite similarity index) and their biogeographical affinity with nations bordering the Indian Ocean was determined. Indicator species analyses were performed to identify the characteristic species of the different plant communities and their biotopes. Results The DCA analysis shows a clustering of sites (plant communities) corresponding with their geographical position, linked in turn to the prevailing environmental conditions of the different coastal areas. The combined interpretation of the ordination, similarity and biogeographical analyses results in the aggregation of similar plant communities of both upwelling areas into four biotopes. Main conclusions The north coast communities of Socotra and the west coast communities of Masirah can be grouped into three biotopes related to the degree of exposure (to upwelling) and sedimentation. These biotopes are typified by indicator species, characteristic for specific substrata, and have a high biogeographical affinity with the East African coast. The plant communities of Socotra's south coast and Masirah's east coast constitute a fourth biotope, being diverse and species rich, typified by a large proportion of red macroalgae including the characteristic species of the unique Arabian Sea flora. This biotope has a pronounced biogeographical affinity with distant regions (disjunctly distributed taxa) as South Africa's East Coast and Western Australia. Within the different biotopes, the communities of Masirah are more divergent from an East African flora in comparison to Socotra, the latter being a stepping stone between the East African and Arabian Sea flora.     

Structure of a community of testate amoebae in a sphagnum dominated bog in upper sura flow (Middle Volga Territory)

Fifty nine species of testate amoebae were found in a sphagnum moss bog located in the upper Sura flow (Volga highland). The active diversity in communities of sphagnum moss biotopes was formed by 24 species. Minimal species diversity (3 species) and maximum density of organisms were noted in the driest habitat. In the habitats with the medium humidity levels, the level of species richness was similar (13–16 species) and the total density was determined by redox characteristics of the environment: under the conditions of oxygen deficit, it was two to three times lower than in an oxidized environment. The species composition specificity in sphagnum moss biotopes was determined by the degree of humidity: in the driest habitats, Arcella arenaria predominated; in the biotopes with medium humidity, Nebela tenella and Hyalosphenia elegans; and in the most humid biotopes, Hyalosphenia papilio and Heleopera sphagni. Communities of testate amoebae differed by species composition and integral characteristics at different sphagnum moss horizons: the abundance and species richness increased with depth. The proportion of living individuals in the total number of tests was 35 to 75%.     

Biotopic distribution, population structure, and some features of small mammal reproduction in Chisinau City

Comparative analysis of species composition, biotopic distribution, population structure, and reproduction of rodents and insectivores in Chisinau City was performed in October?CNovember 2008 (3029 traps days, 715 animals). Sylvaemus sylvaticus appeared to be the most numerous and widely distributed species, the reproductive strategy of which consisted of intense reproduction in the summer. The second most abundant species was Microtus rossiaemeridionalis, which had a different reproductive strategy, with part of its population continuing to reproduce actively in the autumn. Urban woodlands are the most close to natural biotopes by the species composition. The highest number of animals was defined for meadows and gardens. No rodents and insectivores are found on lawns and waste grounds.     

Testate amoebae communities in the southern tundra and forest-tundra of Western Siberia

The species composition and community structure of soil-inhabiting testate amoebae communities have been studied in biotopes of different types in the southern tundra and forest-tundra of the Tazovskaya Lowland, Western Siberia. A total of 93 species and forms have been identified. It has been found that the species richness of testate amoebae is much lower in dry than in moist biotopes due to a lower level of beta-diversity, with alpha diversity being the same (on average, 16.9 and 17.1 species per sample, respectively). Factors acting at the microbiotope level (biotope type and moisture) play the most important role in the formation of species richness; biotope features (soils and vegetation) are second in importance. In moist habitats, local communities of testate amoebae from different microbiotopes (mosses, lichens, or litter) are fairly similar in species structure, and communities from different moist biotopes are heterogeneous. In dry areas, the opposite situation is observed: local communities differ at the microbiotope level but are similar at the biotope level. The abundance of testate amoebae in moist biotopes reaches 200 × 10³ ind./g dry soil, being an order of magnitude lower in dry biotopes.     

Harvest mites of the family Trombiculidae in the steppe zone of the southeastern Ukraine

Virgin and cultivated biotopes of the Sea of Azov area of Donetsk Province were investigated for parasite coenoses of small mammals. 469 animals and 210 nests were collected, Apodemus sylvaticus, Mus musculus, Microtus arvalis and Cricetulus migratorius being the most abundant species. In all 2940 larvae of trombiculids (18 species) were found on animals and in their nests (2846 specimens on animals and 94 specimens in nests). Two species, Hoffmannina theodori and Doloisia skljari, are new for science, the latter being the first find of the genus Doloisia member in the fauna of the USSR. The majority of parasites are collected from rodents inhabiting virgin biotopes (2328 specimens) while in cultivated biotopes 189 specimens were collected. More rich is the species composition of trombiculids in virgin biotopes (13 species) as compared to that in cultivated ones (5 species), Neotrombicula earis, N. japonica, N. autumnalis and N. vulgaris being mass species. 8 species of larvae are recorded from the nests of rodents. Seasonal dynamics of the abundance of mass species, their occurrence, index of abundance and infection intensity are shown.     

Modelling potential biotope composition on a regional scale revealed that climate variables are stronger drivers than soil variables

Aim

Environmental conditions define the suitability of an area for biotopes, and any area can be suitable for several biotopes. However, most previous studies modelled the distribution of single biotopes ignoring the potential co-occurrence of biotopes in one area, which limits the usefulness of such models for conservation and restoration planning. In this study, we described the potential biotope composition of an area in response to environmental conditions.

Location

Bavaria, Federal State of Germany.

Methods

Based on the Bavarian biotope mapping data, we modelled the distribution of 29 terrestrial biotopes based on six climate variables and six chemical and four physical soil properties using the species distribution modelling algorithm Maxent.

Results

For most biotopes, we found that climate variables were more important than soil variables for the biotope distribution and that the area of the predicted biotope distribution was larger than the observed distribution. The potential biotope composition illustrated that while 8% of the area in Bavaria was not sufficiently suitable for any analysed biotope, 92% of the modelled area in Bavaria was suitable for at least one biotope, 84% for two and 77% for at least three biotopes. The difference in suitability between the most suitable biotopes in composition was minor. Further, over one-quarter of the modelled area was suitable for 6–8 different biotopes.

Main Conclusions

Our study showed that considering a composition of potentially suitable biotopes in a raster cell, instead of only the most suitable biotope, provides valuable information to identify conservation priorities and restoration opportunities.     

Biotope distribution of cestodes from the common shrew Sorex araneus in southern Karelia

Specific features in the formation of cestode species composition in the common shrew in different biotopes have been analyzed. Four categories of parasites have been recognized depending on a degree of dominance: dominants (Neoskrjabinolepis singularis, Molluscotaenia crassiscolex), subdominants (Ditestolepis diaphana), adominants A (Staphylocystis furcata, Vigisolepis spinulosa, adominants B (Hymenolepis scutigera, Dilepis undula, D. secunda, Taenia mustelae). A significant similarity was discovered between the species diversity and the dominance characteristics of cestodes. It was found that the distribution of mass species of parasites in the host population corresponds to the gamma distribution model. In regard to cestodes examined, a hypothesis considering the spatial structure and size of territory occupied by stable parasitic system is put forward.     

Composition of Archaea in Seawater,Sediment, and Sponges in the Kepulauan Seribu Reef System,Indonesia

Coral reefs are among the most diverse and productive ecosystems in the world. Most research has, however, focused on eukaryotes such as corals and fishes. Recently, there has been increasing interest in the composition of prokaryotes, particularly those inhabiting corals and sponges, but these have mainly focused on bacteria. There have been very few studies of coral reef Archaea, despite the fact that Archaea have been shown to play crucial roles in nutrient dynamics, including nitrification and methanogenesis, of oligotrophic environments such as coral reefs. Here, we present the first study to assess Archaea in four different coral reef biotopes (seawater, sediment, and two sponge species, Stylissa massa and Xestospongia testudinaria). The archaeal community of both sponge species and sediment was dominated by Crenarchaeota, while the seawater community was dominated by Euryarchaeota. The biotope explained more than 72 % of the variation in archaeal composition. The number of operational taxonomic units (OTUs) was highest in sediment and seawater biotopes and substantially lower in both sponge hosts. No “sponge-specific” archaeal OTUs were found, i.e., OTUs found in both sponge species but absent from nonhost biotopes. Despite both sponge species hosting phylogenetically distinct microbial assemblages, there were only minor differences in Kyoto Encyclopedia of Genes and Genomes (KEGG) functional pathways. In contrast, most functional pathways differed significantly between microbiomes from sponges and nonhost biotopes including all energy metabolic pathways. With the exception of the methane and nitrogen metabolic pathway, all energy metabolic pathways were enriched in sponges when compared to nonhost biotopes.     

Distribution of heterotrophic flagellates at the littoral of estuary of Chernaya River (Kandalaksha Bay, White Sea)

Species composition, distribution, and the character of structural changes in the heterotrophic flagellate community were studied along environmental gradients in the Chernaya River estuary. There were 99 species and forms of heterotrophic flagellates, subdivided into three groups: prevalently marine species and euryhaline species preferring biotopes either of higher or decreased salinity. The heterotrophic flagellate community of the estuary was continuously divided into two distinct variants: (1) cenosis of halophilic species, prevalently of sea forms and euryhaline species preferring biotopes of increased salinity; (2) cenosis of halophobic species with prevalence of euryhaline forms gravitating to fresh biotopes. The arbitrary and indistinct boundary between the variants of the community ran at a salinity of 9–10‰. The response of estuarine communities of heterotrophic flagellates and infusorians to variation of abiotic factors was similar and differed from response of communities of microphyto-, meiozoo-and macrozoobenthos; this implied similarity of the response mechanism to environmental factors in organisms of one level of organization.     

Dynamics of species diversity of Cyclostomata and fishes in the Kuybyshev Reservoir

For the first time, the precise species composition of Cyclostomata and fishes of the Kuybyshev Reservoir is presented at various phases of formation of its ecosystem. Special traits and tendencies of distribution of alien species in it are analyzed. The greatest changes occurred at the first phase. During subsequent phases, the species composition was supplemented mainly due to penetration of southern short-lived alien species with fractional spawning which successfully withstand the increasing anthropogenous impact. Penetration of alien species did not entail disappearance of aboriginal species as the colonizers occupied new limnophilic biotopes not demanded by the aboriginal ichthyofauna.     

Fauna and population structure of springtails (Hexapoda,Collembola) in zonal forest-steppe biotopes of the Middle Volga River basin

A total of 92 springtail species were revealed in forest-steppe areas of the Privolzhskaya Lesostep nature reserve. The considerable part of the species (25–40%) are inhabitants of steppe and open sites with the predominance of soil forms. The specific features of the chernozem soil fauna are determined by the rare species occupying deep soil layers. In different forest-steppe biotopes, the springtail communities are similar in the species composition but differ in the structure. Steppe and forest types of communities were distinguished. When the steppe is forested, the most drastic changes in the collembolan population are revealed in the transitional shrub zone. The marginal community is characterized by the most even structure and a variable set of dominants.     

Characteristics of plant communities containing St. John’s wort (<Emphasis Type="Italic">Hypericum perforatum</Emphasis> L.) in the Saratov Region

Analysis of 28 plant communities containing Hypericum perforatum L. in five different biotope types has been performed in 17 districts of the Saratov Region. A total of 325 species from 197 genera of 52 vascular plant species have been recorded, with plants characteristic of forest-edge, steppe, and anthropogenic biotopes prevailing in most communities. It has been shown that H. perforatum at the southeastern boundary of its range behaves as an explerent species. The main factor limiting its growth in biotopes of a certain type is the degree of disturbance in the structure of corresponding communities rather than by their taxonomic composition.     

Blood-sucking midges of the floodplain of the Sylva River (Ceratopogonidae)

21 species of bloodsuckling midges were recorded from the Kishert region of the Perm district. During the period of investigation the group obsoletus was most abundant, then the group pulicaris and fascipennis. There was noted a poor adaptation of midges to different biotopes and high ecological plasticity of mass species. Specific composition of midges attacking man and domestic animals is more diverse as compared to species attacking birds. Food specialisation is more distinct in ornithophilous species.     

Zur Ökologie der Acoela (Turbellaria) in der Deutschen Bucht

Ecological investigations on the turbellarian order Acoela were carried out from 1962 to 1965 in List (Sylt), Helgoland, Wilhelmshaven and Juist. The sediments in the eulittoral of the Frisian Islands (Juist) and the Jade are structurally rather similar; sediment mobility or muddy components prevent establishment of an interstitial fauna. Helgoland possesses a great variety of different biotopes; this island harbors the highest number of species in the southern North Sea. In contrast to Juist, Sylt offers predominantly sandy biotopes; in addition to the mudliving species of the epifauna, a number of typical interstitial species was recorded. Of 82 species of Turbellaria Acoela identified, only 1 lives in greater sediment depths; all others are confined to the uppermost centimeters or millimeters of the sediment. Besides the sediment boundaries, the low water line forms an important population barrier. The differences in the sediments can be related to specific morphological and habitual adaptations of their inhabitants. Acoela living in interstitial spaces possess mostly a long and slender body form, which, in turn is correlated to internal organization. Most Acoela species which exist in the spaces between sand grains have an unpaired ovary, shifted from near the statocyst to the area behind the mouth opening. Big vacuoles in the peripheral parenchym counteract mechanical deformation by the sediment. Fixation mechanisms occur in form of tail plates, adhesive glands or caudal organs. The body of mud-living Acoela is usually short and stout. Special structural adaptations are absent. The determining factors in the colonization of mesopsammal biotopes are structure and composition of the sediment. Quantitative investigations at List on Sylt reveal the Acoela speciesHaplogonaria syltensis andPseudaphanostoma psammophilum as being stenotope and stenobath.H. syltensis reaches population densities under favorable circumstances of up to 1500 individuals per 2.5 cm³. InHaplogonaria syltensis andPseudaphanostoma psammophilum annual population fluctuations are not attributable to their reproductive phases which depend upon the season; population decline during summer and displacement from optimal living spaces is due to the vigorous development of competing oligochaetes and archiannelides.     

Environmental tuning of an insect ensemble: The tenebrionid beetles inhabiting a Mediterranean coastal dune zonation

Few studies have investigated insect ensembles, i.e. phylogenetically bounded groups of species that use a similar set of resources within a community. The zonation of dune vegetation makes these ecosystems ideal for the study of insect ensembles in a short space. In this study, we investigated if the tenebrionid beetles forming an ensemble on a dune zonation showed variations in community organization (relative abundances and species diversity) in different but spatially associated biotopes defined by different plant communities. Three biotopes (corresponding to European Commission habitat 2110, 2120 and 2230) of a well-preserved Mediterranean dune were sampled using square plots of 2 × 2 m at three places. To investigate if there was some association between species and habitat we applied a χ² test. Variations in community structure parameters were investigated using Shannon index. The three biotopes host tenebrionid communities with similar species composition and overall abundances, confirming that they form a single ensemble. However, tenebrionid species are differently associated with different biotopes along the zonation, with some species occurring with different proportions among the biotopes. A local selection process can be postulated as a mechanism responsible for these differences.     

Biotopes and spatial organization of arthropod communities

Plant, spider, beetle, and ground beetle communities were studied in different agrolandscape biotopes (a wheat field, a field margin, and a forest belt) of Krasnodar Territory. In these biotopes, borders between plant communities were distinct. On the contrary, arthropod communities were not usually confined to the certain biotopes. The high degree of mobility of arthropod species resulted in a decrease in their association with the biotope. Representatives of some species (especially, beetles) were revealed in all the biotopes. In relation to season and some other factors, they frequently concentrated in different biotopes. Analysis of arthropod assemblages only within a single biotope gives us a rather impoverished knowledge of the whole population. It is necessary to study these assemblages not only within the basic biotope, but also in adjacent ones.     

Composition of the fauna and the communities’ structure of the Cicadina (Homoptera) in the lowland Trans-Volga woodlands

179 species of 7 families of the Cicadina were found in the lowland Trans-Volga woodlands within Nizhniy Novgorod Province, the Republic of Mari El, and Chuvashia. Thirty-tree commonest species were distinguished, and their abundance was compared. Comparison of the species composition of the Cicadina complexes in the model biotopes has shown the greatest similarity between the complexes in the birch forests and spruce forests.