Olivier Verneau

• University of Perpignan

The red-eared slider, Trachemys scripta elegans (Wied, 1938), has been introduced worldwide, partly because of the exotic pet trade in the 1980s and 1990s. When T. s. elegans is released or escapes into natural environments, it often establishes new feral populations due to its tolerance for a variety of aquatic ecosystems. Therefore, it is now con...

Human activities affect terrestrial and aquatic habitats leading to changes at both individual and population levels in wild animal species. In this study, we investigated the phenotype and demographics of the Mediterranean pond turtle Mauremys leprosa (Schweigger, 1812) in contrasted environments of Southern France: two peri-urban rivers receiving...

This chapter focus on specific techniques and procedures relevant to the study of polystomatid flatworms. We report from what is known in the literature and from personal experience. Information conveyed in this chapter should not be seen as a complete guide of all relevant techniques. Curiosity and innovation are equally important, and one should...

Regarding the diversity of polystomatids (Chaps. 4 and 5), along with their unique life-history strategies (Chap. 6) and evolution (Chap. 7), it is evident that much remains to be studied and endless species remain undiscovered. Here we provide a list of topics that, in our opinion, require further attention. Working more closely with herpetologist...

This chapter brings together all known polystomes of amphibians, namely 135 spp. from all three extant orders Anura (frogs and toads), Urodela (salamanders) and Apoda (caecilians). For each of the species, we provide information on type material, reference to the description, etymology, type locality, host identity, geographical distribution, site...

Polystomatid flatworms radiated and co-evolved with their sarcopterygian hosts, namely the Australian lungfish, amphibians, freshwater turtles and the common hippopotamus. They are generally strictly host and site-specific with a close synchronization of their life cycle with that of their host, which is the key to their diversification success. Th...

Phylogenetic relationships within polystomatids have been extensively studied for the past 20 years by means of several molecular markers, including 18S and 28S rRNA slow-evolving genes to explore deepest evolutionary nodes, and 12S rRNA, COI and ITS1 fast-evolving genes and intergene to investigate recent ones. In this chapter, we underline all th...

Polystomatid flatworms have been present in the scientific literature as far back as 1758, the year that Carl Linnaeus introduced the binomial classification system. At first discoveries came in at a snail’s pace but dramatically increased to the more than 200 species currently known from 30 genera. This section reviews the history of discoveries o...

Polystomatids (Polystomatidae) are platyhelminthes of the class Monogenea. While monogeneans are mainly fish parasites, all polystomatids, with a single exception, namely Concinnocotyla australensis (Reichenbach-Klinke, 1966) of the Australian lungfish, infect semi-aquatic tetrapods. The outlines of the Polystomatidae sensu Sinnappah et al. (Mol Ph...

This chapter brings together all known polystomes of fish, i.e. the Australian lungfish, chelonians and mammal, i.e. the common hippopotamus, namely 67 spp. For each species we provide information on the type material, reference to the description, etymology, type locality, host identity, host geographical distribution, site of infection, morphomet...

Haemogregarines are blood parasites with a life-cycle involving a vertebrate as the intermediate host and an invertebrate as the definitive host and vector. Extensive phylogenetic investigations based on 18S-rRNA gene sequences have shown that Haemogregarina stepanowi (Apicomplexa: Haemogregarinidae) is able to infest a large diversity of freshwate...

Pollution contributes to the degraded state of continental aquatic ecosystems and biodiversity. Some species appear to be tolerant to aquatic pollution, yet little is known about the effects of such pollution on population structure and dynamics. Here, we investigated how wastewater treatment plant (WWTP) effluents of the Cabestany City, in souther...

Purpose: Despite Madagascar's high amphibian diversity of more than 400 species, only a few polystome species are known from the island. The dissection of frogs from museum collections, together with amphibian and parasite surveys conducted in Madagascar led to the discovery of an undescribed polystome infecting Aglyptodactylus madagascariensis. T...

While monogenean worms are mainly parasites of the gills and skin of fish, and to a lesser extent parasites of the oral cavity, urinary bladder, and/or conjunctival sacs of amphibians and freshwater turtles, Oculotrema hippopotami Stunkard, 1924 is the single monogenean polystome reported from a mammal, the common hippopotamus (Hippopotamus amphibi...

Even if Archaea deliver important ecosystem services and are major players in global biogeochemical cycles, they remain poorly understood in freshwater ecosystems. To our knowledge, no studies specifically address the direct impact of xenobiotics on the riverine archaeome. Using environmental DNA metabarcoding of the 16S ribosomal gene, we previous...

Polystomatids are platyhelminth parasites that infect mainly amphibians and freshwater turtles. For more than seven decades, chelonian polystomes were classified into three genera according to the number of hamuli, i.e. absent for Neopolystoma , one pair for Polystomoidella and two pairs for Polystomoides . Following re-examination of morphological...

Polystomatids are platyhelminth parasites that infect mostly amphibian and chelonian hosts. Polystomatid of testudines were, for more than seven decades, classified in the three genera – Neopolystoma Price, 1939, Polystomoides Ward, 1917 and Polystomoidella Price, 1939. The genus delimitation was primarily based on the absence of hamuli in Neopolys...

Polystomatid flatworms of amphibians are represented in the Neotropical realm by species of Mesopolystoma, Nanopolystoma, Parapseudopolystoma, Polystoma, Riojatrema and Wetapolystoma but only species of Polystoma are known from Brazil, namely Polystoma cuvieri, P. knoffi, P. lopezromani and P. travassosi. During a survey of monogeneans infecting am...

Pollution contributes to the degraded state of continental aquatic ecosystems and biodiversity. Some species appear to be tolerant to aquatic pollution, yet little is known about the effects of such pollution on population structure and dynamics. Here, we investigated how wastewater treatment plant (WWTP) effluents of the Cabestany City, in souther...

IntroductionPseudocapillaria (Ichthyocapillaria) bumpi n. sp. (Nematoda: Capillariidae) is described from specimens infecting the digestive tract of the West African lungfish, Protopterus annectens (Owen) (Lepidosireniformes: Protopteridae).Methods Nematodes were collected in Karingani Game Reserve, Southern Mozambique and studied using light micro...

Herein, we describe several newly-collected specimens of Neopolystoma cf. orbiculare from the urinary bladder of 2 alligator snapping turtles, Macrochelys temminckii (Troost in Harland, 1835) (Cryptodira: Chelydridae Gray, 1831) from Comet Lake (30°35'46.94″N, 88°36'3.12″W), Pascagoula River, Mississippi. Our specimens differed from all previous de...

Although Madagascar has more than 350 frog species of which all but two are endemic to the island, the known polystome (Monogenea: Polystomatidae) diversity parasitizing Malagasy frogs is low, encompassing five species of Madapolystoma, one species of Kankana and one Metapolystoma. Investigating the parasite diversity of frog parasites at selected...

Species of Haemogregarina are apicomplexan blood parasites that use vertebrates as intermediate hosts. Due to limited interspecific morphological characters within the genus during the last decade, 18S rRNA gene sequences were widely used for species identification. As coinfection patterns were recently reported from nuclear molecular data for two...

Polystomes (Monogenea: Polystomatidae) of freshwater turtles are currently represented by five genera, namely Neopolystoma, Polystomoides, Polystomoidella, Uropolystomoides and Uteropolystomoides. These parasites can infect the urinary, oral and/or the conjunctival sac systems of their hosts, showing strict site specificity. A recent phylogenetic s...

Assessing the extant distribution of wildlife species is a crucial step towards promoting their protection and management in the light of global biodiversity decline, and even more so when threatened, vulnerable, rare, or endemic taxa are concerned. In this context, we present an overview of the biogeography of two freshwater turtle species, namely...

Haemogregarina species are apicomplexan blood parasites infecting vertebrates such as fish, lizards, and turtles. Due to the high morphological similarity of the erythrocytic stages infecting host species, it has always been a challenge to identify the true diversity of these parasites. Therefore, taxonomic studies are presently based on the combin...

Rivers are representative of the overall contamination found in their catchment area. Contaminant concentrations in watercourses depend on numerous factors including land use and rainfall events. Globally, in Mediterranean regions, rainstorms are at the origin of fluvial multipollution phenomena as a result of Combined Sewer Overflows (CSOs) and fl...

The polystomes (Monogenea, Polystomatidae) radiated across semi-aquatic tetrapods including all three amphibian orders, freshwater turtles and the hippopotamus. Prior to this study, phylogenetic analyses revealed that the most diverse and widespread genus, Polystoma, was not monophyletic; a lineage comprising four undescribed species from the bladd...

Les tortues toutes espèces confondues, marines, d’eau douce et terrestres font partie des Vertébrés actuels les moins diversifiés. C’est pour cette raison en partie, que leur étude à des fins de conservation a connu un regain d’intérêt ces deux dernières décennies. En Tunisie, si deux espèces de tortues d’eau douce sont actuellement recensées, la c...

Two frog species, Blommersia domerguei and Mantella expectata, are reported as hosts for new species of Madapolystoma. Phylogenetic analyses and genetic divergences observed in the genus supported the distinction of two morphotypes infesting selectively each host species and morphological investigation combining marginal hooklet morphometrics, geni...

Increased use of chemical pesticides to protect crop plants may have adverse effects on the environment. In this context, biocontrol products could be considered. To date, the half-life, t1/2, was often employed to evaluate the environmental fate of pesticides. However, this value has a limitation as it doesn’t describe all the phenomena occuring a...

Freshwater ecosystems face very strong anthropogenic pressures, among which overexploitation, habitat degradation, flow modification, species invasion, and water pollution lead to growing threats on biodiversity. Urbanization through wastewater treatment, industry through the release of inorganic and organic chemicals, and agriculture through the u...

The North American red-eared slider Trachemys scripta elegans, which is nowadays considered among the world’s worst invasive species, could constitute a real threat to native freshwater turtles. Because this species shares the same habitats of the European pond turtle Emys orbicularis since its introduction in the European wetlands, we surveyed pop...

Increasing anthropogenic activities, like agricultural practices, constitute the main causes of the loss of water quality and disruption of freshwater ecosystems. High concentrations of pesticides, as shown under experimental conditions, can indeed impact freshwater animals. In Southern France, especially in the Pyrénées-Orientales department, beca...

In an interconnected world, the international pet trade on wild animals is becoming increasingly important. As a consequence, non-native parasite species are introduced, which affect the health of wildlife and contribute to the loss of biodiversity. Because the investigation of parasite diversity within vulnerable host species implies the molecular...

Polystomes are monogenean parasites that infest mainly semi aquatic vertebrates, such as amphibians and chelonians. Owing to the lack of discriminative morphological characters and because polystomes are considered to be strictly host- and site-specific, host identity is often used as an additional character for parasite identification. Recent gene...

Background Polystomatid flatworms in chelonians are divided into three genera, i.e. Polystomoides Ward, 1917, Polystomoidella Price, 1939 and Neopolystoma Price, 1939, according to the number of haptoral hooks. Among the about 55 polystome species that are known to date from the 327 modern living chelonians, only four species of Polystomoides are c...

Contaminants found in watercourses are not only the result of anthropogenic activities but also depend on river's seasonal hydrodynamics. This is particularly true in Mediterranean climate regions where long dry periods are interrupted by strong rainfalls. Storm events remobilize particles from soils and sediments and, as a consequence, the load of...

Chelonian polystomes (Monogenea: Polystomatidae) inhabit three different locations on their respective hosts, namely the conjunctival sacs under the eyes, oral region and pharyngeal pouch, and the urinary bladder. Although chelonian polystomes form a monophyletic group, the genera Polystomoides and Neopolystoma are, according to published molecular...

Freshwater turtle species are still poorly understood, and many species are in decline due to unsustainable trade as well as human alteration and degradation of freshwater ecosystems. Mauremys leprosa is a freshwater chelonian endemic to the Mediterranean Basin. Whereas the fossil record demonstrates that this species used to be distributed to well...

Novel fossil discoveries have contributed to our understanding of the evolutionary appearance of parasitism in flatworms. Furthermore, genetic analyses with greater coverage have shifted our views on the co-evolution of parasitic flatworms and their hosts. The putative record of parasitic flatworms is consistent with extant host associations and so...

The red-eared slider turtle, Trachemys scripta elegans, is among the most over-exploited animals and is still exported annually from the USA all over the world. Once introduced into its new environment, feral populations may arise and pose threats to local biodiversity and ecosystem functioning. In France, it is in fact considered as a risk for the...

An expedition was undertaken to French Guiana in search of amphibian parasites. Of the 23 anuran species collected and screened for polystomes, the toad Rhinella margaritifera (Laurenti) was the sole species found to be infected with a polystome, namely Wetapolystoma almae Gray, 1983. Of the two caecilian species collected, a new species of Nanopol...

Parasite host-switching from the invasive American red-eared slider, Trachemys scripta elegans, to the native Mediterranean pond turtle, Mauremys leprosa, in natural environments

Throughout th e world freshwater turtles are traded for the food market and as pets. It’s estimated that between 1988 and 1994 roughly 26 million turtles were exported worldwide. Though some countries banned turtle imports, 3 - 4 million turtle hatchlings are still annual ly exported from the USA. Some turtles are released or escape into the enviro...

Six M. leprosa turtles were collected in the south of France. • Infected with Polystomoides sp. and Neopolystoma sp. in the bladder. • Housed individually in plastic boxes containing water to the depth of about 20 mm. • Containers were placed outside to expose them to environmental temperatures. • Parasite egg production was monitored daily over a...

Considering the addition of intermediate transmission steps during life cycle evolution, developmental plasticity, canalization forces and inherited parental effect must be invoked to explain new host colonization. Unfortunately, there is a lack of experimental procedures and relevant models to explore the adaptive value of alternative developmenta...

To optimise host-to-host transmission, digenean trematodes (parasites) synchronize their cercarial emission patterns with the aquatic activities of their vertebrate hosts. Schistosoma mansoni has a strictly diurnal shedding pattern involving two circadian chronotypes: an early shedding pattern with a mean peak occurring at 11:00 h and a late patter...

As gevolg van die troeteldiermark en voedselbedryf is sommige varswaterskilpaaie wêreldwydversprei. Onvolwasse skilpaaie is dikwels baie aantreklik en kleurvol, maar hulle is geneig om hulle helder kleure te verloor hoe ouer hulle word.

Eel virus European X (EVEX) was first isolated from diseased European eel Anguilla anguilla in Japan at the end of seventies. The virus was tentatively classified into the Rhabdoviridae family on the basis of morphology and serological cross reactivity. This family of viruses is organized into six genera and currently comprises approximately 200 me...

Lamellodiscus Johnston & Tiegs 1922 (Monogenea, Diplectanidae) is a genus of common parasites on the gills of sparid fishes. Here we show that this genus is probably undergoing a fast molecular diversification, as reflected by the important genetic variability observed within three molecular markers (partial nuclear 18S rDNA, Internal Transcribed S...

Investigating patterns and processes of parasite diversification over ancient geological periods should involve comparisons of host and parasite phylogenies in a biogeographic context. It has been shown previously that the geographical distribution of host-specific parasites of sarcopterygians was guided, from Palaeozoic to Cainozoic times, mostly...

Kankana manampoka n. gen., n. sp. (Monogenea, Polystomatidae), is described from the urinary bladder of the narrow-mouthed frog Platypelis pollicaris. This is the first record of a polystome from the Microhylidae and the third polystome genus from Madagascar, next to Metapolystoma and Madapolystoma. The extensive uterus and presence of hamuli resem...

One of the major threats to biodiversity involves biological invasions with direct consequences on the stability of ecosystems. In this context, the role of parasites is not negligible as it may enhance the success of invaders. The red-eared slider, Trachemys scripta elegans, has been globally considered among the worst invasive species. Since its...

Polystoma nacialtuneli n. sp. is described from the urinary bladder of the eastern spadefoot, Pelobates syriacus from Turkey. This is the fifth polystome species known from Turkey and the third species in Pelobates. We show that this new parasite species can be distinguished from other polystome species in the area by a combination of characteristi...

Madapolystoma n. g. (Monogenea, Polystomatidae), is proposed for a new genus of polystomatid from the urinary bladder of the Malagasy poison frogs of the genus Mantella (family Mantellidae), with the description of one new species. This is the second anuran polystome to be described from Madagascar. The parasites are small with a maximum body lengt...

A key issue in Evolutionary Developmental Biology is to assess the roles of homeotic genes in order to uncover the origins of animal diversity. Within parasitic platyhelminths which show a large diversity of developmental strategies, only one study related to the expression of Hox genes has so far been conducted involving a digenean species with a...

Among parasitic platyhelminths with complex life cycles, it has been well documented that transmission opportunities are the main forces shaping the diversity of life-history traits and parasite developmental strategies. While deviations in the development pathway usually involve shortening of life cycles, their extension may also occur following p...

Most integrative studies involving phylogenetic, developmental and ecological trends showed that the diversity of developmental modifications among the Platyhelminthes was linked to transmission opportunity pressures. For parasitic flatworms with complex life cycles it was suggested that the evolutionary forces that constrained or enhanced developm...

Hox genes form a multigenic family that play a fundamental role during the early stages of development. They are organised in a single cluster and share a 60 amino acid conserved sequence that corresponds to the DNA binding domain, i.e. the homeodomain. Sequence conservation in this region has allowed investigators to explore Hox diversity in the m...

Cophylogenetic studies investigate the evolutionary trends within host-parasite associations. Examination of the different levels of fidelity between host and parasite phylogenies provides a powerful tool to inspect patterns and processes of parasite diversification over host evolution and geological times. Within the phylum Platyhelminthes, the mo...

Polystomatid flatworms are parasites of high host specificity, which mainly infect amphibian hosts. Only one polystome species has so far been recorded from Madagascar despite the high species richness and endemicity of amphibians on this island. Out of the 86 screened Malagasy frog species, we recovered polystomes from 25 in the families Ptychaden...

Among monogeneans that display direct life cycles, plastic developmental strategies may have been selected to counter the lack of transmission opportunities. Within amphibian polystomatids, some species of the genus Polystoma develop into two different phenotypes depending on the host physiological stage to which free swimming larvae attach. When o...

We investigated whether host specificity is linked to variability within species of Lamellodiscus monogeneans, which are gill ectoparasites of the Sparidae. We sampled fish parasites in the northeastern part of the Mediterranean Sea: 4 specialist species, using 1 single host species, and 3 generalist species, using 2 distinct host species. Intraspe...

Polystoma floridana is described as a new species of the Polystomatidae parasitic in the urinary bladder of Hyla cinerea in Gainesville, Florida, USA. This is the fifth polystome from an anuran host described from North America but only the third belonging to the genus Polystoma. Here we show that the parasite from H. cinerea is a separate species....

Polystoma floridana is described as a new species of the Polystomatidae parasitic in the urinary bladder of Hyla cinerea in Gainesville, Florida, USA. This is the fifth polystome from an anuran host described from North America but only the third belonging to the genus Polystoma. Here we show that the parasite from H. cinerea is a separate species....

Patterns and likely processes connected with evolution of host specificity in congeneric monogeneans parasitizing fish species of the Cyprinidae were investigated. A total of 51 Dactylogyrus species was included. We investigated (1) the link between host specificity and parasite phylogeny; (2) the morphometric correlates of host specificity, parasi...

The family Labridae contains numerous fishes known to act as cleaners in the wild. Previous studies suggested that a small body size and specific colour patterns may be prerequisites for cleaning. We investigated whether cleaning behaviour is linked to particular fish phenotypes. We first present a phylogeny based on partial 12S rRNA gene sequences...

Aim The present-day geographical distribution of parasites with a direct biological life cycle is guided mostly by the past dispersal and vicariance events that have affected their hosts. The Amphibia–Polystoma association (which satisfies these criteria) also exhibits original traits, such as host specificity and world-wide distribution. This biol...

Several species of flatfishes (Pleuronectiformes) have been studied by isoenzyme electrophoresis and DNA/DNA hybridization to establish the evolutionary relationships of this group of fishes. This molecular data-based phylogeny has been compared to previously described phylogenies based on morpho-anatomical criteria. A number of discrepancies are o...

Anisakiasis is the infestation of man by the third larval stage of the Anisakidae family parasites, caused by the consumption of raw or undercooked seafood. The hosts of the third larvae parasite are marine fishes, among which Sardina pilchardus is of high commercial interest in many countries. So, the detection of anisakid larvae in fisheries prod...

Within the class Monogenea, three clades are currently recognized : the Polyonchoinea, the Oligonchoinea and the Polystomatoinea. While most monogeneans parasitize chondrichthyan and teleost fishes, the Polystomatoinea re the only group parasiting terrestrial vertebrates, i.e. freshwater tetrapods and the Dipnoi. They are represented by two familie...

Within the class Monogenea, three clades are currently recognized: the Polyonchoinea, the Oligonchoinea and the Polystomatoinea. While most monogeneans parasitize chondrichthyan and teleost fishes, the Polystomatoinea are the only group parasiting terrestrial vertebrates, i.e. freshwater tetrapods and the Dipnoi. They are represented by two familie...

Dactylogyrus species (Dactylogyridae: Monogenea) are a group of monogenean gill parasites that are highly specific to freshwater fish of the family Cyprinidae. Dactylogyrus species were sampled from 19 cyprinids and one percid collected in Europe. Using partial 18S rDNA and ITS1 sequences, a phylogeny of 51 Dactylogyrus species was reconstructed to...

Analyses of small subunit ribosomal RNA gene sequences of representatives of major taxa of Monopisthocotylea were performed to identify the sister group of Gyrodactylus. Nuclear ribosomal DNA sequences from the complete internal transcribed spacer (ITS) region were used to infer phylogeny of 37 Gyrodactylus species and Gyrodactyloides bychowskii, M...

The Monogenea, which is divided into two clades, namely the Monopisthocotylea and Polyopisthocotylea, is a highly diversified group of platyhelminth parasites that infest mainly actinopterygian and chondrichthyan fishes but also, to a lesser extent, freshwater sarcopterygian hosts. Euzetrema knoepffleriCombes, 1965 (Monogenea: Iagotrematidae), whic...

Phylogenetic analyses based on partial 18S rDNA sequences of polyonchoinean monogeneans were conducted in order to investigate the relationships between selected families and subfamilies of the Dactylogyrinea, mainly within the Dactylogyridae. We tested the status of the Ancyrocephalidae sensu Bychowsky & Nagibina (1978) and the Ancyrocephalinae se...

In this study, we characterized for the first time the complete sequence of a L37a cDNA from a cestode specie: Taenia crassiceps. A phylogenetic analysis of L37a ribosomal proteins from distant animal species is presented and the potential use of such proteins in molecule-based phylogeny is discussed.

The Polystomatidae is the only family within the Monogenea to parasitize sarcopterygians such as the Australian lungfish Neoceratodus poisteri and freshwater tetrapods (lissamphibians and chelonians). We present a phylogeny based on partial 18S rDNA sequences of 26 species of Polystomatidae and three taxon from the infrasubclass Oligonchoinea (= Po...

Nucleotide sequence data from the mitochondrial 12S rRNA and cytochrome b genes were used to analyze phylogenetic relationships among sciurognath rodents. Our sample taxa included representatives of 11 sciurognath and 3 hystricognath families with two marsupial species, Didelphis virginiana and Macropus robustus, as outgroups. The dataset was analy...

We reviewed several published and ongoing studies concerning monogenean communities. Patterns of species richness, host specificity, community structure and host--parasite coevolutionary interaction were carefully analysed, and hypotheses of evolutionary processes are proposed. The structuring of monogenean communities seems to be related to both e...

The origin and the evolution of Schistosomatidae species, due to their medical importance (responsible of the second most important human parasitosis after malaria), arouse a great interest. A combination of phylogenetic studies using several molecular markers has provided support for the traditional grouping and evolutionary inferences derived fro...

The origin and the evolution of Schistosomatidae species, due to their medical importance (responsible of the second most important human parasitosis after malaria), arouse a great interest. A combination of phylogenetic studies using several molecular markers has provided support for the traditional grouping and evolutionary inferences derived fro...