In the present study, we analyzed the morphology of three genetic types of the bird-infecting acanthocephalan Polymorphus cf. minutus (PspT1, PspT2, PspT3), mainly based on the cystacanth-stage obtained from amphipods (Gammarus fossarum, Gammarus pulex, Gammarus roeselii, Echinogammarus spp.). Males and females were pooled as there was no considerable difference between the sexes concerning the hook measurements. Additionally, we conducted a laboratory infection of one domestic duck for each Polymorphus type, to compare their performance and localization in this host species, and to obtain adult specimens for morphological comparison. The recovery rate from the ducks 4 weeks after infection was 16% for PspT1, 23.8% for PspT2, and 25% for PspT3. The adult worms were gravid, and the females contained mature eggs. Hook size did not differ considerably between cystacanths and adults of the respective type. The three Polymorphus types could be distinguished based on the cystacanth stage by a linear discriminant analysis that included hook measurements, proboscis length, proboscis width, and number of longitudinal hook rows and hooks per row. Furthermore, PspT3 was more different from PspT1 and PspT2 than the latter types from each other. Mainly the number of longitudinal hook rows differed in PspT3 from the existing descriptions of P. minutus (mainly 14 vs. mainly 16 rows). Potentially, PspT3 could be a non-indigenous parasite that was introduced with G. roeselii and that adapted to use the indigenous G. pulex as a host, while PspT2 might have been introduced to central Europe together with Echinogammarus spp.

• MeSH
• Acanthocephala anatomy & histology   classification   isolation & purification   MeSH
• Amphipoda parasitology   MeSH
• Cell Differentiation MeSH
• Helminthiasis, Animal parasitology   pathology   MeSH
• Host-Parasite Interactions MeSH
• Ducks parasitology   MeSH
• Birds MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Comparative Study MeSH
• Geographicals
• Europe MeSH

Locomotion is an important, fitness-related functional trait. Environment selects for type of locomotion and shapes the morphology of locomotion-related traits such as body size and appendages. In subterranean aquatic arthropods, these traits are subjected to multiple, at times opposing selection pressures. Darkness selects for enhanced mechano- and chemosensory systems and hence elongation of appendages. Conversely, water currents have been shown to favor short appendages. However, no study has addressed the variation in locomotion of invertebrates inhabiting cave streams and cave lakes, or questioned the relationship between species' morphology and locomotion. To fill this knowledge gap, we studied the interplay between habitat use, morphology and locomotion in amphipods of the subterranean genus Niphargus. Previous studies showed that lake and stream species differ in morphology. Namely, lake species are large, stout and long-legged, whereas stream species are small, slender and short-legged. We here compared locomotion mode and speed between three lake and five stream species. In addition, we tested whether morphology predicts locomotion. We found that the stream species lie on their body sides and move using slow crawling or tail-flipping. The species inhabiting lakes move comparably faster, and use a variety of locomotion modes. Noteworthy, one of the lake species almost exclusively moves in an upright or semi-upright position that resembles walking. Body size and relative length of appendages predict locomotion mode and speed in all species. We propose that integrating locomotion in the studies of subterranean species might improve our understanding of their morphological evolution.

• MeSH
• Amphipoda physiology   MeSH
• Behavior, Animal MeSH
• Species Specificity MeSH
• Ecosystem * MeSH
• Locomotion * MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Groundwater is an extreme environment due to its absence of light, resource scarcity and highly fragmentary nature. Successful groundwater colonizers underwent major evolutionary changes and exhibit eye and pigment loss (troglomorphies). Consequently, their chances of dispersal and survival in the well-connected surface waters are greatly decreased, resulting in significant endemism. The West Palaearctic subterranean amphipod genus Niphargus comprises hundreds of narrowly endemic and troglomorphic species. Nevertheless, a few are known to occur in surface waters, two of which, N. hrabei and N. valachicus, have extremely large ranges that even exceed those of many surface-water amphipods. We tested if this pattern results from a secondary colonization of the relatively well-connected epigean environment, and whether this ecological shift promoted the large-scale dispersal of these species. Results showed that despite their ecological and zoogeographic similarities, N. hrabei and N. valachicus are not closely related and independently colonized surface waters. Their phylogeographic patterns indicate Middle to Late Pleistocene dispersal episodes throughout the Danube lowlands, and relatively modest yet significant genetic differentiation among populations. Clustering based on morphology revealed that the two species are phenotypically closer to each other than they are to most other epigean congeners. We presume that the ecological shift to surface environments was facilitated by their ability to thrive in hypoxic waters where rheophilic competitors from the family Gammaridae cannot survive. In conclusion, our results indicate that adaptation to groundwater is not a one-way evolutionary path and that troglomorphic species can occasionally recolonize and widely disperse in surface waters.

• MeSH
• Amphipoda genetics   physiology   MeSH
• Bayes Theorem MeSH
• Biological Evolution MeSH
• Species Specificity MeSH
• Phenotype MeSH
• Phylogeny MeSH
• Phylogeography MeSH
• Haplotypes genetics   MeSH
• Animal Migration physiology   MeSH
• Groundwater * MeSH
• Polymorphism, Genetic MeSH
• Cluster Analysis MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

The aim of the present study was to investigate the presence and bioaccumulation of new flame retardants (nBFRs), polybrominated diphenyl ethers (PBDEs) and dechlorane plus (DDC-CO) in the marine environment close to an Arctic community. Passive sampling of air and water and grab sampling of sediment and amphipods was used to obtain samples to study long-range transport versus local contributions for regulated and emerging flame retardants in Longyearbyen, Svalbard. BDE-47 and -99, α- and β-tetrabromoethylcyclohexane (DBE-DBCH), syn- and anti-dechlorane plus (DDC-CO) were detected in all investigated matrices and the DDC-COss at higher concentrations in the air than reported from other remote Arctic areas. Water concentrations of ΣDDC-COSs were low (3 pg/L) and comparable to recent Arctic studies. ΣnBFR was 37 pg/L in the water samples while ΣPBDE was 3 pg/L. In biota, ΣDDC-COSs dominated (218 pg/g ww) followed by ΣnBFR (95 pg/g ww) and ΣPBDEs (45 pg/g ww). When compared with other areas and their relative distribution patterns, contributions from local sources of the analysed compounds cannot be ruled out. This should be taken into account when assessing long-range transport of nBFRs and DDC-COs to the Arctic. High concentrations of PBDEs in the sediment indicate that they might originate from a small, local source, while the results for some of the more volatile compounds such as hexabromobenzene (HBBz) suggest long-range transport to be more important than local sources. We recommend that local sources of flame retardants in remote areas receive more attention in the future.

• MeSH
• Amphipoda MeSH
• Bromobenzenes analysis   MeSH
• Hydrocarbons, Chlorinated analysis   MeSH
• Halogenated Diphenyl Ethers analysis   MeSH
• Environmental Monitoring methods   MeSH
• Polycyclic Compounds analysis   MeSH
• Flame Retardants analysis   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Arctic Regions MeSH
• Svalbard MeSH

A novel species of aseptate eugregarine, Ganymedes yurii sp. n., is described using microscopic and molecular approaches. It inhabits the intestine of Gondogeneia sp., a benthic amphipod found along the shore of James Ross Island, Weddell Sea, Antarctica. The prevalence of the infection was very low and only a few caudo-frontal syzygies were found. Morphologically, the new species is close to a previously described amphipod gregarine, Ganymedes themistos, albeit with several dissimilarities in the structure of the contact zone between syzygy partners, as well as other characteristics. Phylogenetic analysis of the 18S rDNA from G. yurii supported a close relationship between these species. These two species were grouped with other gregarines isolated from crustaceans hosts (Cephaloidophoroidea); however, statistical support throughout the clade of Cephaloidophoroidea gregarines was minimal using the available dataset.

• MeSH
• Amphipoda parasitology   MeSH
• Apicomplexa classification   genetics   ultrastructure   MeSH
• Phylogeny MeSH
• Microscopy MeSH
• DNA, Protozoan genetics   MeSH
• DNA, Ribosomal genetics   MeSH
• RNA, Ribosomal, 18S genetics   MeSH
• Base Sequence MeSH
• Sequence Analysis, DNA MeSH
• Microscopy, Electron, Transmission MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Antarctic Regions MeSH

Isolated glacial refugia have been documented in Central Europe for a number of taxa, but conclusive evidence for epigean aquatic species has remained elusive. Using molecular data (mitochondrial and nuclear markers), we compared the spatial patterns of lineage diversity of the widely distributed Gammarus fossarum species complex between two adjacent biogeographically and geomorphologically distinct Central European regions: the Bohemian Massif and the Western Carpathians. We investigated if the observed patterns of spatial diversity are more likely to stem from historical or present-day factors. Phylogenetic and phylogeographic analyses revealed eight phylogenetically diverse lineages: two exhibiting local signatures of recent demographic expansion inhabit both regions, while the other six display a relict distributional pattern and are found only in the Western Carpathians. Molecular dating indicates that these lineages are old and probably diverged throughout the Miocene (7-18Ma). Furthermore, their distribution does not seem to be constrained by the present boundaries of river catchments or topography. The contrasting spatial patterns of diversity observed between the two regions thus more likely result from historical rather than contemporaneous or recent factors. Our results indicate that despite the high latitude and proximity to the Pleistocene ice sheets, the Western Carpathians functioned as long-term glacial refugia for permanent freshwater fauna, allowing the uninterrupted survival of ancient lineages through millions of years of drastic climatic fluctuations.

• MeSH
• Amphipoda genetics   physiology   MeSH
• Bayes Theorem MeSH
• Time Factors MeSH
• Phylogeny MeSH
• Phylogeography MeSH
• Genetic Variation MeSH
• Mitochondria genetics   MeSH
• Altitude MeSH
• Climate * MeSH
• Refugium * MeSH
• Base Sequence MeSH
• Sequence Analysis, DNA MeSH
• Geography MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Europe MeSH

To identify trematode diversity and life-cycles in the sub-Arctic Lake Takvatn, Norway, we characterised 120 trematode isolates from mollusc first intermediate hosts, metacercariae from second intermediate host fishes and invertebrates, and adults from fish and invertebrate definitive hosts, using molecular techniques. Phylogenies based on nuclear and/or mtDNA revealed high species richness (24 species or species-level genetic lineages) and uncovered trematode diversity (16 putative new species) from five families typical in lake ecosystems (Allocreadiidae, Diplostomidae, Plagiorchiidae, Schistosomatidae and Strigeidae). Sampling potential invertebrate hosts allowed matching of sequence data for different stages, thus achieving molecular elucidation of trematode life-cycles and exploration of host-parasite interactions. Phylogenetic analyses also helped identify three major mollusc intermediate hosts (Radix balthica, Pisidium casertanum and Sphaerium sp.) in the lake. Our findings increase the known trematode diversity at the sub-Arctic Lake Takvatn, showing that digenean diversity is high in this otherwise depauperate sub-Arctic freshwater ecosystem and indicating that sub-Arctic and Arctic ecosystems may be characterised by unique trematode assemblages.

• MeSH
• Amphipoda parasitology   MeSH
• Bayes Theorem MeSH
• Invertebrates parasitology   MeSH
• Ecosystem MeSH
• Phylogeny MeSH
• Genetic Variation * MeSH
• Haplotypes MeSH
• Snails parasitology   MeSH
• Insecta parasitology   MeSH
• Trematode Infections parasitology   veterinary   MeSH
• Lakes parasitology   MeSH
• Mollusca classification   parasitology   MeSH
• Bivalvia parasitology   MeSH
• Fish Diseases parasitology   MeSH
• Fishes MeSH
• Sequence Alignment MeSH
• Trematoda classification   genetics   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Arctic Regions MeSH
• Norway MeSH

The high demand for new antibacterials fosters the isolation of new biologically active compounds producing actinobacteria. Here, we report the isolation and initial characterization of cultured actinobacteria from dominant benthic organisms' communities of Lake Baikal. Twenty-five distinct strains were obtained from 5 species of Baikal endemic macroinvertebrates of amphipods, freshwater sponges, turbellaria worms, and insects (caddisfly larvae). The 16S ribosomal RNA (rRNA)-based phylogenic analysis of obtained strains showed their affiliation to Streptomyces, Nocardia, Pseudonocardia, Micromonospora, Aeromicrobium, and Agromyces genera, revealing the diversity of actinobacteria associated with the benthic organisms of Lake Baikal. The biological activity assays showed that 24 out of 25 strains are producing compounds active against at least one of the test cultures used, including Gram-negative bacteria and Candida albicans. Complete dereplication of secondary metabolite profiles of two isolated strains led to identification of only few known compounds, while the majority of detected metabolites are not listed in existing antibiotic databases.

• MeSH
• Actinobacteria chemistry   classification   isolation & purification   metabolism   MeSH
• Amphipoda microbiology   MeSH
• Anti-Infective Agents chemistry   metabolism   MeSH
• Bacteria drug effects   MeSH
• Invertebrates microbiology   MeSH
• Phylogeny MeSH
• Insecta microbiology   MeSH
• Fungi drug effects   MeSH
• Lakes microbiology   MeSH
• Porifera microbiology   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Differences in life histories are commonly exhibited within ecological communities, especially among species that display increased variations in body size and morphology and are phylogenetically distant. To examine the relationship between morphological dissimilarity and life history divergence, we investigated three morphologically distinct and distantly related species of freshwater amphipods that co-occur throughout the Danube lowlands - Gammarus balcanicus dacicus, Niphargus valachicus and Synurella ambulans - by collecting monthly samples during a one-year period. Results revealed that the studied species differ significantly with respect to fecundity, size at maturity, number of generations per year, duration and timing of the reproductive period and egg volume. Despite some overlap, each species possesses a unique combination of traits, supporting the hypothesis that life history variation within freshwater amphipod communities can reflect dissimilarities regarding body size, morphology and evolutionary relationships. However, it is not yet clear which of these factors has the most significant contribution to life history divergence.

• MeSH
• Amphipoda anatomy & histology   classification   growth & development   physiology   MeSH
• Phylogeny MeSH
• Reproduction MeSH
• Fresh Water MeSH
• Pregnancy MeSH
• Body Size MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Pregnancy MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Romania MeSH

The life cycle of the swim bladder nematode Huffmanela huffmani Moravec, 1987 (Trichinelloidea: Trichosomoididae), an endemic parasite of centrarchid fishes in the upper spring run of the San Marcos River in Hays County, Texas, USA, was experimentally completed. The amphipods Hyalella cf. azteca (Saussure), Hyalella sp. and Gammarus sp. were successfully infected with larvated eggs of Huffmanela huffmani. After ingestion of eggs of H. huffmani by experimental amphipods, the first-stage larvae hatch from their eggshells and penetrate through the digestive tract to the hemocoel of the amphipod. Within about 5 days in the hemocoel of the experimental amphipods at 22 °C, the larvae presumably attained the second larval stage and were infective for the experimental centrarchid definitive hosts, Lepomis spp. The minimum incubation period before adult nematodes began laying eggs in the swim bladders of the definitive hosts was found to be about 7.5 months at 22 °C. This is the first experimentally completed life cycle within the Huffmanelinae.

• MeSH
• Amphipoda parasitology   MeSH
• Time MeSH
• Nematoda physiology   MeSH
• Nematode Infections parasitology   MeSH
• Fish Diseases parasitology   MeSH
• Perciformes parasitology   MeSH
• Life Cycle Stages * MeSH
• Air Sacs parasitology   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Texas MeSH