Biology subjects

Kmentova, N.

Publications and source records attributed to Kmentova, N..

10 recordsLinked to original sources

bioRxiv2026

A baseline for aquatic parasite diversity in West African mangroves: host-parasite records, DNA barcodes, and an experimental design for future use

Macroparasites represent a major fraction of biodiversity and biomass in marine ecosystems, yet remain substantially underrepresented in ecological surveys and food-web models, particularly in the Global South. This study addresses this geographic bias by providing the first comprehensive ecological survey of macroparasite communities of fishes in a West African Marine Protected Area (MPA) and adjacent Open-Access Area (OAA) characterised by mangrove forests. We collected 5,020 parasite specimens from 10 fish and one crab species in the Saloum Delta, Senegal, identifying 27 parasite species across all major taxa. Our findings include 15 new records for Senegal of which 11 are also new for West Africa. Additionally, 64% of host-parasite combinations constitute new host records. We provide 208 DNA barcodes, offering the first molecular data for 31% of these species globally and establishing a reference library for future DNA metabarcoding efforts in the region. Using sample size-corrected biodiversity indices and mixed-model analyses, we detected significant variations in parasite infracommunities and component communities between the MPA and OAA, demonstrating the feasibility of using comparative study designs to monitor fisheries impacts on parasite diversity in the Saloum Delta. Furthermore, the identification of trophically transmitted parasites provided evidence of unstudied food-web connections, e.g. predator-prey linkages between fishes and higher-trophic-level definitive hosts including birds and elasmobranchs. By integrating morphological identification, molecular data, and archiving of voucher specimens into publicly accessible, curated collections, this study establishes a new baseline for marine parasite biodiversity in West Africa and provides a methodological blueprint for surveying understudied regions.

zoology↗

bioRxiv2026

155 years after Van Beneden: redescription and first molecular characterisation of the enigmatic type species, Ascarophis morrhuae Van Beneden, 1870 (Nematoda, Cystidicolidae), and comparison to other Ascarophis species in the North Atlantic

Nematodes belonging to the Cystidicolidae Skrjabin, 1946 constitute more than 23 genera of 111 recognized species in fish from many habitats including the deep-sea, continental shelves, estuarine and freshwater habitats. The taxonomy of many species within the Cystidicolidae is unsettled due to their small size and correspondingly small morphological characters requiring use of scanning electron microscopy and supported more recently by molecular studies. The type species, Ascarophis morrhuae Van Beneden, 1870, which belongs to one of the first described and most speciose cystidicolid genera with 46 species, is based on a two-sentence description of a single female specimen from an Atlantic cod, Gadus morhua, presumably captured off the coast of Belgium in the North Sea (Van Beneden, 1870). New material was collected/examined from Atlantic cod and haddock, Melanogrammus aeglefinus, from Iceland and the North Sea and specimens present in the Natural History Museum, London were also studied. Based on these materials, A. morrhuae is morphologically redescribed and the first DNA sequences of this species are provided, it is differentiated from other Ascarophis species present in the North Atlantic and previous records are reviewed. This information provides a foundation for taxonomic and phylogenetic reconsideration of all cystidicolid nematodes and related families.

zoology↗

bioRxiv2024

Ergasilid copepods in Africa: first application of next-generation sequencing and update on distribution and phylogenetic position of Ergasilus kandti, a parasite of cichlid fishes

Ergasilidae are a family of globally distributed copepods parasitizing freshwater fish. Despite their widespread occurrence, their phylogeographic patterns are poorly understood, specifically in the African Great Lakes. Here, we aim to provide an update on distribution of Ergasilus kandti, a copepod species infecting Tylochromis polylepis, an endemic cichlid fish species in Lake Tanganyika, and the phylogenetic relationship of African ergasilids. We present the first record of E. kandti parasitizing the gills of T. polylepis in Lake Tanganyika proper, identified through light microcopy and, for the first time for any ergasilid, confocal laser scanning microscopy. We suggest that this technique adds spatial context to characters and are hardly visible while using light microscopy. Phylogenetic analyses based on ribosomal DNA fragments suggest two monophyletic groups of African ergasilids. However, the phylogenetic relationships of Ergasilus remain unresolved, possibly because of the insufficient resolution of these widely used phylogenetic markers and low taxonomic coverage. A comparison of ergasilid mitochondrial genomes highlights traits found in other parasite lineages including genome shrinkage and low evolutionary rates of the cox1 gene. This study presents the most extensive molecular characterization of any ergasilid species to date.

zoology↗

bioRxiv2023

All Quiet on the Western Front? The evolutionary history of monogeneans (Dactylogyridae: Cichlidogyrus, Onchobdella) infecting a West and Central African tribe of cichlid fishes (Chromidotilapiini)

Owing to the largely unexplored diversity of metazoan parasites, their speciation mechanisms and the circumstances under which such speciation occurs--in allopatry or sympatry--remain vastly understudied. Cichlids and their monogenean flatworm parasites have previously served as study system for macroevolutionary processes, e.g. for the role of East African host radiations on parasite communities. Here, we investigate the diversity and evolution of the poorly explored monogeneans infecting a West and Central African lineage of cichlid fishes: Chromidotilapiini Greenwood, 1987, which is the most species-rich tribe of cichlids in this region. We screened gills of 149 host specimens (27 species) from natural history collections and measured systematically informative characters of the sclerotised attachment and reproductive organs of the parasites. Ten monogenean species (Dactylogyridae: Cichlidogyrus and Onchobdella) were found, eight of which are described and one redescribed herein. The phylogenetic positions of chromidotilapiines-infecting species of Cichlidogyrus were inferred through a parsimony analysis of the morphological characters. Furthermore, we employed machine learning algorithms to detect morphological features associated with the main lineages of Cichlidogyrus. Although the results of these experimental algorithms remain inconclusive, the parsimony analysis indicates that West and Central African lineages of Cichlidogyrus and Onchobdella are monophyletic, unlike the paraphyletic host lineages. Several instances of host sharing suggest occurrences of intra-host speciation (sympatry) and host switching (allopatry). Some morphological variation was recorded that may also indicate the presence of species complexes. We conclude that collection material can provide important insights on parasite evolution despite the lack of well-preserved DNA material. Data availability statementType material was deposited in the invertebrate collection of the Royal Museum for Central Africa (Tervuren, Belgium) (RMCA) (RMCA_VERMES_XXXXX-XXX), the collection of the Research Group Zoology: Biodiversity and Toxicology of Hasselt University (Diepenbeek, Belgium) (HU XXX-XXX), the Finnish Museum of Natural History (Helsinki, Finland) (MZH XXXXX-XXX), and the Iziko South African Museum (Cape Town, South Africa) (SAMC-XXXXXXX-XXX). The morphological data that support the findings of this study are openly available in MorphoBank at www.morphobank.org, at https://dx.doi.org/XXXXXXXX. Phylogenetic trees and data matrices for the analysis in TNT are included as additional data in MorphoBank.

evolutionary biology↗

bioRxiv2023

Lifestyle and not density of fish hosts determines parasite distribution over time and space

Despite their important ecological role, questions remain on mechanisms structuring parasite assemblages. We present a simple and endemic host-parasite system of clupeid fishes and monogenean parasites (Kapentagyrus, Dactylogyridae) with contrasting levels of host-specificity from Lake Tanganyika as a model to study parasite distribution patterns and co-infection dynamics in nature. With two parasites, two host species, and three host-parasite combinations between them, this unique system represents the simplest natural host-parasite model that is not trivial. We modelled spatiotemporal dynamics of host-parasite interaction using infection data along the North-South axis of Lake Tanganyika (660 km) over the course of two seasons and four years (1730 fish, 3710 parasites). We found temporal stability of infection, which contrasts with previously reported seasonally driven fluctuations of fish host abundances. We found a difference in spatial structure between the parasite species, confirming that their distributions are only restricted by their most mobile host species. On the host species that is infected by two parasite species, we discovered a positive correlation with host body size for one parasite species, and a negative correlation for the other species. As we also discovered facilitation of infection, this cannot be due to competition. The differences reported between parasite species infecting the same host species further extrapolate the dependence on changes in lifestyle of the host during its ontogenetic development. In conclusion, we show that in a simple, closed system parasite infection dynamics are dependent on a combination of host mobility, host lifestyle changes over ontogenetic development and interspecific interactions between parasites.

ecology↗

bioRxiv2022

The black goby Gobius niger Linnaeus, 1758 in the Marchica lagoon (Alboran Sea, Morocco): Ecological traits and site-related footprint

Fishes belonging to Gobiidae are well represented in the Marchica lagoon on the Moroccan Mediterranean coast, both in terms of species richness and abundance, with the black goby, Gobius niger Linnaeus, 1758, being the dominant species. The present study aims to examine (1) the spatial and temporal distribution of Gobius niger and its environmental drivers in the lagoon and (2) the potential lagoon-related footprint using morphometric, genetic and parasitological proxies. Systematic monthly sampling covering the whole lagoon basin performed between October 2015 and September 2016 revealed year-long presence of G. niger throughout the lagoon with significantly low densities in winter. The higher abundances were recorded in the shallow bottoms of the lagoon inner margins on a variety of substrates (mud, muddy-sand, sandy-mud and fine sand) mostly covered by macroalgae and/or seagrass meadows. Depth, that has to be seen as a variable that acts in concert with other factors such as temperature, vegetation cover and sediment as the Mean Grain Size, seems to be the most important predictor, explaining the distribution of G. niger in the lagoon, with a trend of increasing abundance towards shallower stations. Comparison of black goby populations from the Marchica lagoon with their counterparts from the adjacent Mediterranean coast of Morocco revealed that specimens caught at sea are of a bigger size compared to the lagoon population. Of the 180 gobies investigated, not a single one hosted the parasites we targeted in the parasitological approach, monogenean flatworms. The absence of population structuring, low genetic diversity and presence of common haplotypes indicate no apparent restriction in the gene flow between the two populations. Therefore, the observed morphometric differences seem to be due to the external environmental conditions rather than genetic differences. Gobius niger plays a key eco-trophic role by providing a link between benthic invertebrates and large predators. The shallow beds of the lagoon, where the species is abundant, are key habitats in the Marchica lagoon and need to be considered in all management plans aiming at the conservation of biodiversity and ecological processes.

ecology↗

bioRxiv2022

Ectoparasitism in Polystomatidae (Neodermata, Monogenea): phylogenetic position and mitogenome of Sphyranura euryceae, a parasite of the Oklahoma salamander

BackgroundPolystomatidae represents a monogenean group whose representatives infect mainly (semi)-aquatic tetrapods. Sphyranuridae with its single genus (Sphyranura) exhibits ectoparasitism on salamander hosts and was traditionally considered a sister-group to Polystomatidae based on the presence of a well-developed opisthaptor yet was distinguished due to the presence of a single pair of haptoral suckers, as opposed to the three pairs present in polystomatids. However, more recent molecular work supported its inclusion within Polystomatidae, at an early diverging, yet unresolved, position in the clade of polystomatids that otherwise exhibit endoparasitism of batrachians. Resolving the position of Sphyranura in relation to Polystomatidae is a prerequisite for understanding the factors driving evolution and the shifts between ecto- and endoparasitism in Polystomatidae. MethodsVarious staining methods were used to morphologically characterise collected specimens of Sphyranura. The mitochondrial genome was assembled from WGS data. Based on a combination of nuclear (18S, 28S rRNA) and mitochondrial markers (cox1, 12S) we inferred the phylogeny of Polystomatidae using Bayesian inference and maximum likelihood methods. ResultsBased on morphological examination and comparison with type material, specimens of Sphyranura infecting Oklahoma salamander (Eurycea tynerensis) at Greathouse Spring, Arkansas (USA), were identified as S. euryceae, a new distributional record for the species. Along with an amended diagnosis of Sphyranura we provide the first molecular data for S. euryceae. Mitochondrial level comparison reveals instances of tRNA gene rearrangements in polystomatids. Our phylogeny identifies two clades within polystomatids infecting tetrapods, one infecting exclusively batrachians, the other mainly known from chelonians. Although not fully supported, Sphyranura appears as the earliest branching lineage within the former. ConclusionsWith Sphyranura nested within Polystomatidae, we consider Sphyranuridae invalid. Sphyranuras apparent early branching position indicates ectoparasitism is an ancestral trait with endoparasitism having evolved later in the Polbatrach clade. However, the reduced number of haptoral suckers in representatives of Sphyranura is a derived characteristic potentially resulting from paedomorphic evolution. Whilst there is an indication towards phylogenetic congruence of polystomatids and their batrachian hosts, the same was not true for polystomatid parasites of chelonians with evidence of multiple host switches. Furthermore, geographic distribution of hosts was not found to drive polystomatid phylogeny.

evolutionary biology↗

bioRxiv2022

Like host, like parasite: intraspecific divergence in a polystomatid flatworm parasite across South Africa echoes that of its frog host

The African Clawed Frog Xenopus laevis, a global invader, exhibits marked phylogeographic divergence among native populations in southern Africa, which enhances its invasive potential. The polystomatid flatworm Protopolystoma xenopodis, as the frogs most frequently co-introduced metazoan parasite, may be the ideal biological tag for the frogs movement, if corresponding divergence can be demonstrated. In an integrative approach, we utilised morphometrics and molecular markers to assess divergence in P. xenopodis in its native range. We measured twelve key morphological characters from 23 flatworms and compared these statistically between flatworms collected to the north and south of the Great Escarpment Mountain Range in South Africa. Phylogenetic analyses were based on three concatenated markers, namely 28S and 12S rDNA and COX1, from six flatworms. The combination of five morphological characters, which involve egg size, gut morphology and size of the attachment hooks, differentiated northern and southern populations of P. xenopodis in South Africa. The multilocus phylogenetic analyses supported these findings, showing a well-supported cluster of northern P. xenopodis. These findings suggest that taxonomic studies of polystomatid flatworms should make use of geographically representative data sets that consider both morphological and molecular evidence. Moreover, the findings demonstrate that the frog host and flatworm parasite exhibit corresponding phylogeographic structuring in the native range. Consequently, the phylogeography of P. xenopodis, both in the native and invasive range of its host, may act as a key piece of evidence to reconstruct past invasion pathways of X. laevis.

zoology↗

bioRxiv2021

Widespread anthropogenic translocation of the African Clawed Frog across its native range is revealed by its co-introduced monogenean parasite in a co-phylogeographic approach

O_LIThe management of bio-invasions relies upon the development of methods to trace their origin and expansion. Co-introduced parasites, especially monogenean flatworms, are ideal tags for the movement of their hosts due to their short generations, direct life cycles and host specificity. However, they are yet to be applied to trace the intraspecific movement of host lineages in their native ranges. C_LIO_LIAs proof of this concept, we conducted a comparative phylogeographic analysis based upon two mitochondrial markers of a globally invasive frog Xenopus laevis and its monogenean parasite Protopolystoma xenopodis in its native range in southern Africa and invasive range in Europe. C_LIO_LITranslocation of lineages was largely masked in the frogs phylogeography. However, incongruent links between host and parasite phylogeography indicated host switches from one host lineage to another after these were brought into contact in the native range. Thus, past translocation of host lineages is revealed by the invasion success of its co-introduced parasite lineage. C_LIO_LIThis study demonstrates that parasite data can serve as an independent line of evidence in invasion biology, also on the intraspecific level, shedding light on previously undetected invasion dynamics. Based upon the distribution of these invasive parasite lineages, we infer that there is widespread anthropogenic translocation of this frog, not only via official export routes, but also facilitated by the frogs use as live bait by angling communities. C_LIO_LISynthesis and applications. Data from co-introduced, host-specific parasites, as tags for translocation, can add value to investigations in invasion biology and conservation. A better understanding of the translocation history and resulting genetic mixing of host and parasite lineages in the native range can shed light on the genetic make-up of parasite assemblages co-introduced to the invasive range. Knowledge of the intraspecific movement of different lineages of animals in their native ranges also has conservation implications, since contact between divergent lineages of hosts and parasites can facilitate host switches and altered parasite dynamics in both native and invasive populations. Therefore, we recommend the inclusion of parasite data as a more holistic approach to the invasion ecology of animals on the intraspecific level. C_LI

ecology↗

bioRxiv2020

Parasitic flatworms infecting thorny skate, Amblyraja radiata: infection by the monogeneans Acanthocotyle verrilli and Rajonchocotyle emarginata in Svalbard

Parasite diversity above the Arctic circle remains understudied even for commercially valuable host taxa. Thorny skate, Amblyraja radiata, is a common bycatch species with a growing commercial value. Its natural range covers both sides of the North Atlantic including the Arctic zone. Svalbard is a Norwegian archipelago located on the northwest corner of the Barents Shelf which sustains a spectacular species diversity. So far, several monogenean species have been reported infecting thorny skate across the Atlantic Ocean. In the present study, we intend to fill in the knowledge gap on monogenean parasites infecting thorny skate in the northern part of its range and thus indirectly assess the connectivity between the thorny skate populations off the Svalbard coast and from previously studied locations. 46 monogenean individuals were recovered from 11 specimens of thorny skate. Following morphological and molecular assessment, two species of monogeneans, Acanthocotyle verrilli and Rajonchocotyle emarginata, were identified. The results serve as the northernmost record for both parasite genera and the first record of monogenean species off Svalbard. Detailed morphometric evaluation revealed a relatively high level of morphological variation in A. verrilli compared to its congeners. Phylogenetic reconstruction placed A. verrilli in a well-supported clade with A. imo. Our study also suggests high diagnostic significance of sclerotised structures in the identification of Rajonchocotyle. Even though the occurrence of two directly transmitted parasite species supports the previously suggested long-distance migration of A. radiata, future studies employing highly variable genetic markers are needed to assess the ongoing and historical migration patterns. HighlightsO_LIFirst record of monogenean species in Svalbard C_LIO_LINorthernmost record for representatives of Acanthocotylidae and Hexabothriidae C_LIO_LITransatlantic occurrence of parasites supports connectivity of thorny skate populations C_LI

zoology↗