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Prof. Arthur Looss (1861–1923) was a prolific German parasitologist, who, among other things, authored descriptions of 22 new species of nematodes and 115 new species of trematodes. After his death, his collection (including type material) was split between several institutions: Smithsonian National Museum of Natural History in Washington (USA), Natural History Museum in Berlin and the Natural History Museum in Leipzig (Germany), Gothenburg Museum of Natural History and Swedish Museum of Natural History (Sweden). Here we revise all type specimens of nematodes from the A. Looss collection that are currently preserved in the Swedish Museum of Natural History (Strongylus subtilis, Sclerostomum edentatum, S. vulgare, Cyathostomum labratum, C. coronatum, C. bicoronatum, C. calicatum, C. alveatum, C. catinatum, C. nassatum, C. radiatum, C. elongatum, C. auriculatum, Triodontus minor, T. serratus, C. labiatum and Uncinaria polaris), designate and describe lectotypes wherever deemed necessary and provide catalogue access numbers to all type materials. We also revise all notes and drawings associated with new species that A. Looss described and provide previously unpublished pencilled sketches and ink print-ready drawings of some of these species (Strongylus subtilis, Cyathostomum poculatum, C. radiatum, C. elongatum, C. calicatum, C. auriculatum, Triodontus serratus, Trichostrongylus vitrinus and possibly Necator africanus).

Helminths of 12 fish species collected near the South Orkney Islands, West Antarctica were studied. In the whole sample of 115 fish specimens, we identified one species of Monogenea, 5 species of Trematoda, 4 species of Cestoda, 5 species of Nematoda, and 7 species of Acanthocephala. All cestode species, 3 species of nematodes, and 5 species of acanthocephalans were represented only by larval stages; fish are definitive hosts for the remaining 10 helminth species. Details of composition and structure of helminth communities were studied in 3 fish species: Chaenocephalus aceratus (Lönnberg, 1906), Champsocephalus gunnari Lönnberg, 1905, and Pseudochaenichthys georgianus Norman, 1937, each represented by more than 20 specimens in a sample. In these hosts, 19, 8, and 16 helminth species were found, correspondingly. In the helminth communities of C. aceratus and P. georgianus, the highest values of the infection prevalence and abundance were recorded for larval cestodes (Diphyllobothrium sp., Tetrabothriidea), nematodes (Pseudoterranova sp., Contracaecum sp.), acanthocephalans (Corynosoma spp.), as well as adults of the trematode Neolebouria georgiensis Gibson, 1976. The same trematode species and larval cestodes predominated in the helminth community of C. gunnari. All recorded species of parasites are generalists, each known from a range of fish hosts in Antarctica.

Basic knowledge on the biology and epidemiology of equine strongylid species remains insufficient although it would contribute to the design of better parasite control strategies. Nemabiome is a convenient tool to quantify and to identify species in bulk samples that could overcome the hurdle that cyathostomin morphological identification represents. To date, this approach has relied on the internal transcribed spacer 2 (ITS-2) of the ribosomal RNA cistron and its predictive performance and associated biases both remain unaddressed.This study aimed to bridge this knowledge gap using cyathostomin mock communities and comparing performances of the ITS-2 and a cytochrome c oxidase subunit I (COI) barcode newly developed in this study. The effects of bioinformatic parameters were investigated to determine the best analytical pipelines. Subsequently, barcode predictive abilities were compared across various mock community compositions. The replicability of the approach and the amplification biases of each barcode were estimated. Results were also compared between various types of biological samples, i.e. eggs, infective larvae or adults.Overall, the proposed COI barcode was suboptimal relative to the ITS-2 rDNA region, because of PCR amplification biases, a reduced sensitivity and higher divergence from the expected community composition. Metabarcoding yielded consistent community composition across the three sample types, although infective larvae may remain the most tractable in the field. Additional strategies to improve the COI barcode performances are discussed. These results underscore the critical need of mock communities for metabarcoding purposes.

In modern competitive environment, eco-branding constitutes one of the main prerequisites for the effective development of the country's economy. In an unstable economic situation, the reformatting of Ukrainian society is too inert, while the problems are growing rapidly, which is undoubtedly exploited by dishonest players in the consumer goods market. This study considers the lines of development of Ukrainian and world commodity markets, pointing to the need to develop the market of environmentally friendly products based on oil flax, improving the quality of flax-containing products due to the use of advanced technologies and innovative equipment. The research methodology included the monographic method, comparison, analysis, mathematical planning, and graphic method. It is determined that the main prerequisite for sustainable development of the country in the context of economic globalisation, limited resources, and technology development is the use of eco-branding. To increase the efficiency of processing of fibrous material, a method of processing oilseed flax has been developed, which allows expanding the range of processing products of oilseed flax and to create waste-free technology. A method for obtaining the same type of fibre from bast-fibre crops has been developed, which makes it possible to process oil flax stalks. Prospects for the use of the presented technical and technological developments can contribute to the modernisation of the light industry, its further development, expansion of the Ukrainian market, increase jobs and attract highly qualified specialists in the field, increase the competitiveness of Ukrainian products on the world market

The spatial distribution of ciliate assemblages was studied in a shallow floodplain lake with a sharp division of space by oxygen conditions. The surface zone occupied by the “carpet” of Lemna trisulca and L. minor was characterized by a large daily amplitude of oxygen content with periodic exceeding of 100% of saturation; the underlying water layer was characterized by microaerobic conditions throughout most of the year, with seasonal deviations towards oxygen-free conditions (in winter and mid-summer) or increased oxygen content (before freezing and after ice melt); stable oxygen-free conditions were maintained in the bottom layer of water and at the bottom of the lake. There were 111 species of ciliated protozoa recorded in the lake. The ciliated protozoa were clearly structured and formed three almost non-overlapping assemblages in terms of species composition, which retained their isolation during all seasons of the year. On the basis of the analysis performed using the R indicspecies package, species of ciliated protozoa were identified as indicators of conditions with different oxygen regimes, which are determined by the level of organic pollution and the distribution of photosynthetic organisms.

We make new morphological observations not previously reported for the old acanthocephalan Macracanthorhynchus hirudinaceus (Pallas, 1781) Travassos, 1917, described for the first time about 240 years ago. Our specimens were collected from the wild boar, Sus scrofa Linn., in Ukraine in 2005. We provide comparative morphometrics with other populations from Ukraine, Union of Soviet Socialist Republics, Europe, Brazil and the United States of America. Our specimens from the Ukraine had the smallest trunk (110-120 mm long), longest and thickest hooks, with the third hook being the largest, largest eggs, and a proboscis wider than long. We document the morphology of the proboscis, apical organ, hooks, hook roots, sensory pores, micropores, and eggs with scanning electron microscopy for the first time. We also provide chemical analysis of hooks and eggs using energy-dispersive X-ray analysis, discuss its micropores, and provide a new molecular profile based on 18S rDNA from a European population for the first time. Edge of hook tips feature high levels of calcium and phosphorous but the high level of sulphur is mostly found in the cortical layer of eggs. One new partial 18S rDNA sequence (482 nt length) was generated from an adult specimen of M. hirudinaceus. We present the first 18S rDNA published sequence for this cosmopolitan acanthocephalan obtained from Europe. The amplified region corresponded to the approximate middle region of the small subunit ribosomal ribonucleic acid gene, which is ~1800 nt in length. This molecular contribution is especially valuable in light of the extreme scarcity of genetic information about species of Macracanthorhynchus and of the family Oligacanthorhynchidae as a whole.

Echinorhynchus gadi is one of the most widely distributed and commonly described acanthocephalans in marine fishes throughout the world. We provide a detailed morphometric and molecular description of a distinct Alaska population collected from the Pacific halibut Hippoglossus stenolepis Schmidt (Pleuronectidae) compared to those from other hosts and regions, illustrating new features never previously reported.We described new specimens by microscopical studies, augmented by SEM, Energy Dispersive x-ray and molecular analyses, and histopathology.Specimens from Alaska were distinguished from those collected from the other geographical areas in proboscis size and its armature, especially number of hook rows and hooks per row, and length of hooks. The size of the receptacle, lemnisci, and reproductive structures in some other collections also varied from the Alaska material. X-ray scans of the gallium cut hooks depict prominent layering with high Sulfur content for tip cuts and increased calcium and phosphorus content in the base area of the hook. Sections of E. gadi specimens in the host tissue show prominent hook entanglement with subsequent connective tissue invasion also depicting the internal anatomy of certain worm structures not readily seen by other means. Molecular analyses clearly confirmed the identity of our E. gadi sequences.Our Alaska population of the E. gadi complex appears to represent a novel population distinguishable by its distinct morphometrics, geography and host species. We further establish new information on the Energy Dispersive X-ray analysis in our Alaska material for future comparisons with the other siblings and explore genetic relationships among echinorhynchid genera and species.

The celomic system of the articulate brachiopod Hemithyris psittacea is composed of the perivisceral cavity, the canal system of the lophophore, and the periesophageal celom. We study the microscopic anatomy and ultrastructure of the periesophageal celom using scanning and transmission electron microscopy. The periesophageal celom surrounds the esophagus, is isolated from the perivisceral cavity, and is divided by septa. The lining of the periesophageal celom includes two types of cells, epithelial cells and myoepithelial cells, both are monociliary. Some epithelial cells have long processes extending along the basal lamina, suggesting that these cells might function as podocytes. The myoepithelial cells have basal myofilaments and may be overlapped by the apical processes of the adjacent epithelial cells. The periesophageal celom forms protrusions that penetrate the extracellular matrix (ECM) of the body wall above the mouth and the ECM that surrounds the esophagus. The canals of the esophageal ECM form a complicated system. The celomic lining of the external circumferential canals consists of the epithelial cells and the podocyte-like cells. The deepest canals lack a lumen; they are filled with the muscle cells surrounded by basal lamina. These branched canals might perform dual functions. First, they increase the surface area and might therefore facilitate ultrafiltration through the podocyte-like cells. Second, the deepest canals form the thickened muscle wall of the esophagus and could be necessary for antiperistalsis of the gut.