Таксономический статус Neoechinorhynchus agilis (Acanthocephala, Neoechinorhynchidae), с описанием двух новых видов рода от кефалевых рыб (Teleostei, Mugilidae) Атлантики и Пацифики

Широкое географическое распространение, богатый список хозяев, а также значительная вариабельность метрических признаков акантоцефалы Neoechinorhynchus agilis (Rudolphi, 1819) ставит вопрос о таксономическом статусе этого вида. Для проведения сравнительного морфологического анализа был использован типичный материал Рудольфи и ваучерные экземпляры Ямагути, а также собственный материал, собранный в западной части Тихого океана и северо-восточной Атлантике. В результате исследования было обнаружено три вида акантоцефал Neoechinorhynchus, в том числе два вида из Атлантики: N. (N.) agilis и N. (H.) personatus Tkach, Sarabeev et Shvetsova, sp. n., и один вид из Тихого океана, N. (H.) yamagutii Tkach, Sarabeev et Shvetsova, sp. n. Описанные в работе виды хорошо различаются как морфологически, так и метрически. Разделение N. agilis на три вида, два из которых описаны впервые, является основой для дальнейшего пересмотра находок этой акантоцефалы из разных регионов и от разных хозяев.The wide variability in morphological features, geographical and host ranges of mullet acanthocephalan parasite Neoechinorhynchus agilis (Rudolphi, 1819), raises the question of taxonomic status of this species. Rudolphi’s type and Yamaguti`s voucher specimens, as well as our own material from the WW Pacific and NE Atlantic region were used herein to provide comparative morphological analysis. The study revealed three different species of Neoechinorhynchus, N. (N.) agilis and N. (H.) personatus Tkach, Sarabeev et Shvetsova, sp. n. in the Atlantic and N. (H.) yamagutii Tkach, Sarabeev et Shvetsova, sp. n. in the Pacific. Strong morphological and morphometric differences were found between three described herein species from different hosts and regions. The dividing of N. agilis into three species, two of them are new, provides a basis for the further revision of host-geographical records of mullet acanthocephalan parasites

Kudoa unicapsula n. sp. (Myxosporea: Kudoidae) a parasite of the Mediterranean mullets Liza ramada and L. aurata (Teleostei: Mugilidae)

A new multivalvulid myxozoan parasite, Kudoa unicapsula n. sp., is described from the intestinal mesentery, intestine and pyloric caeca of the thin-lipped grey mullet Liza ramada (Risso 1826) and the golden grey mullet L. aurata (Risso, 1810) from the Mediterranean coastal waters of Spain. It is characterized by the presence of elongated, rice corn-like white cysts of 0.47–0.56×0.18–0.38 mm, filled with tetracapsulate, slightly asymmetric spores, rectangular in apical view and tear-shaped in lateral view with four polar capsules of considerably different size and slightly unequal spore valves with rounded edges, overlapping each other on the apex of the spore. One large polar capsule includes a polar filament coiled in two to three turns, and the other three polar capsules, which are very small, posses only a rudimental filament. Both light and electron microscopy data showed that this species differs from all previously described Kudoa spp. with unequal polar capsules. The molecular analysis based on 18S and 28S ribosomal deoxyribonucleic acid DNA sequence data of K. unicapsula n. sp. indicates a close relationship and thus phylogenetic clustering together with K. trifolia, a myxozoan from the same host and the same geographical location

Disentangling the determinants of symbiotic species richness in native and invasive gammarids (Crustacea, Amphipoda) of the Baltic region

Dispersal of alien species is a global problem threatening native biodiversity. Co-introduction of nonnative parasites and pathogens adds to the severity of this threat, but this indirect impact has received less attention. To shed light on the key factors determining the richness of microorganisms in native and invasive host species, we compared symbiotic (parasitic and epibiotic) communities of gammarids across different habitats and localities along the Baltic coast of Poland. Seven gammarid species, two native and five invasive, were sampled from 16 freshwater and brackish localities. Sixty symbiotic species of microorganisms of nine phyla were identified. This taxonomically diverse species assemblage of symbionts allowed us to assess the effect of host translocation and regional ecological determinants driving assembly richness in the gammarid hosts. Our results revealed that (i) the current assemblages of symbionts of gammarid hosts in the Baltic region are formed by native and co-introduced species; (ii) species richness of the symbiotic community was higher in the native Gammarus pulex than in the invasive hosts, probably reflecting a process of species loss by invasive gammarids in the new area and the distinct habitat conditions occupied by G. pulex and invasive hosts; (iii) both host species and locality were key drivers shaping assembly composition of symbionts, whereas habitat condition (freshwater versus brackish) was a stronger determinant of communities than geographic distance; (iv) the dispersion patterns of the individual species richness of symbiotic communities were best described by Poisson distributions; in the case of an invasive host, the dispersion of the rich species diversity may switch to a right-skewed negative binomial distribution, suggesting a host-mediated regulation process. We believe this is the first analysis of the symbiotic species richness in native and invasive gammarid hosts in European waters based on original field data and a broad range of taxonomic groups including Microsporidia, Choanozoa, Ciliophora, Apicomplexa, Platyhelminthes, Nematoda, Nematomorha, Acanthocephala and Rotifera, to document the patterns of species composition and distributio

Optimum sample size to estimate mean parasite abundance in fi sh parasite surveys

[EN] To reach ethically and scientifically valid mean abundance values in parasitological and epidemiological studies this paper considers analytic and simulation approaches for sample size determination. The sample size estimation was carried out by applying mathematical formula with predetermined precision level and parameter of the negative binomial distribution estimated from the empirical data. A simulation approach to optimum sample size determination aimed at the estimation of true value of the mean abundance and its confidence interval (CI) was based on the Bag of Little Bootstraps (BLB). The abundance of two species of monogenean parasites Ligophorus cephali and L. mediterraneus from Mugil cephalus across the Azov-Black Seas localities were subjected to the analysis. The dispersion pattern of both helminth species could be characterized as a highly aggregated distribution with the variance being substantially larger than the mean abundance. The holistic approach applied here offers a wide range of appropriate methods in searching for the optimum sample size and the understanding about the expected precision level of the mean. Given the superior performance of the BLB relative to formulae with its few assumptions, the bootstrap procedure is the preferred method. Two important assessments were performed in the present study: i) based on CIs width a reasonable precision level for the mean abundance in parasitological surveys of Ligophorus spp. could be chosen between 0.8 and 0.5 with 1.6 and 1x mean of the CIs width, and ii) the sample size equal 80 or more host individuals allows accurate and precise estimation of mean abundance. Meanwhile for the host sample size in range between 25 and 40 individuals, the median estimates showed minimal bias but the sampling distribution skewed to the low values; a sample size of 10 host individuals yielded to unreliable estimates.SS and VS were supported by MEDEA project fellowships, Erasmus Mundus Action 2. CC-S was funded by project #MTM2014-52975-C2-1-R:" Inference in Structured Additive Regression (STAR) Models with Extensions to Multivariate Responses. Applications in Biomedicine", cofinanced by the Ministry of Economy and Competitiveness (SPAIN) and by the European Regional Development Fund (FEDER). This study is partially supported by Ministry of Education and Science of Ukraine, project #1/17.Shvydka, S.; Sarabeev, V.; Estruch, VD.; Cadarso-Suarez, C. (2018). Optimum sample size to estimate mean parasite abundance in fi sh parasite surveys. Helminthologia. 55(1):52-59. https://doi.org/10.1515/helm-2017-0054S5259551Rohde, K., Hayward, C., & Heap, M. (1995). Aspects of the ecology of metazoan ectoparasites of marine fishes. International Journal for Parasitology, 25(8), 945-970. doi:10.1016/0020-7519(95)00015-tAnderson, R. M., & Gordon, D. M. (1982). Processes influencing the distribution of parasite numbers within host populations with special emphasis on parasite-induced host mortalities. Parasitology, 85(2), 373-398. doi:10.1017/s0031182000055347Poiani, A. (1992). Ectoparasitism as a possible cost of social life: a comparative analysis using Australian passerines (Passeriformes). Oecologia, 92(3), 429-441. doi:10.1007/bf00317470Kleiner, A., Talwalkar, A., Sarkar, P., & Jordan, M. I. (2014). A scalable bootstrap for massive data. Journal of the Royal Statistical Society: Series B (Statistical Methodology), 76(4), 795-816. doi:10.1111/rssb.12050Jovani, R., & Tella, J. L. (2006). Parasite prevalence and sample size: misconceptions and solutions. Trends in Parasitology, 22(5), 214-218. doi:10.1016/j.pt.2006.02.011BAGGE, A. M., SASAL, P., VALTONEN, E. T., & KARVONEN, A. (2005). Infracommunity level aggregation in the monogenean communities of crucian carp (Carassius carassius). Parasitology, 131(3), 367-372. doi:10.1017/s0031182005007626Belghyti, D., Berrada-rkhami, O., Boy, V., Aguesse, P., & Gabrion, C. (1994). Population biology of two helminth parasites of flatfishes from the Atlantic coast of Morocco. Journal of Fish Biology, 44(6), 1005-1021. doi:10.1111/j.1095-8649.1994.tb01272.xTAYLOR, L. R. (1961). Aggregation, Variance and the Mean. Nature, 189(4766), 732-735. doi:10.1038/189732a

The data file to Shvydka et al, 2020. Patterns of monogenean abundance in native and invasive populations of Planiliza haematocheila (Teleostei: Mugilidae): interactions between climate and host defence mechanisms explain parasite release

Abundance data of Ligophorus llewellyni from the pacific so-iuy mullet, Planiliza haematocheila, in the Azov and Japan Seas with information on locality, month, season, year, host total length (TL), weight (W) and relative host condition (Krelative)

Data files to Sarabeev et al. (2023) Database on eukaryotic symbionts of native and invasive gammarids (Crustacea, Amphipoda) in the Baltic region of Poland with information on water parameters for sampling sites

This database documents the diversity of eukaryotic symbionts from 612 host individuals of seven gammarid species in the Baltic region of Poland. The material of database is composed of three Microsoft® Excel files. The main file represents the raw data on the number of individuals of each eukaryotic symbiont taxa recorded in each host and location. The data set is contained information on the assemblage of symbionts per host individual in one text-table matrix; macro- (host) and microsymbiont taxa name, host length, the date of collection, the geographic coordinates and locality name in columns; and amphipod host specimens in lines. One file reports the microsymbiont species list with information on host species, sampling date, locality and geographic coordinates, infection site, obtained sequences (if the case), brief morphological characteristics and microphotographs. Another file reports measured water parameters, habitat features and host density per sample.THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

The data file to Shvydka et al, 2020. Patterns of monogenean abundance in native and invasive populations of Planiliza haematocheila (Teleostei: Mugilidae): interactions between climate and host defence mechanisms explain parasite release

Abundance data of Ligophorus llewellyni from the pacific so-iuy mullet, Planiliza haematocheila, in the Azov and Japan Seas with information on locality, month, season, year, host total length (TL), weight (W) and relative host condition (Krelative)

Supplementary data to Sarabeev, V.L., Balbuena, J.A., Morand, S. Aggregation patterns of helminths populations in the introduced fish, Liza haematocheilus (Teleostei: Mugilidae): disentangling host-parasite relationships. Int. J. Parasitol.

The data file contains Supplementary Tables S1 and S2