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I. C. Potter - One of the best experts on this subject based on the ideXlab platform.

  • novel relationships among lampreys petromyzontiformes revealed by a taxonomically comprehensive molecular data set
    Lang N.J. Roe K.J. Renaud C.B. Gill H.S. Potter I.C. Freyhof J. Naseka A.M. Cochran P. Pérez H.E. Habit E.M. Kuhajda B.R. Neely D.A. Reshetnikov Y.S. , 2009
    Co-Authors: Nicholas J Lang, Howard S Gill, Alexander M Naseka, Philip A Cochran, Hector Espinosa Perez, Evelyn Habit, Claude B. Renaud, Jorg Freyhof, I. C. Potter, Bernard R. Kuhajda
    Abstract:

    The systematics of lampreys was investigated using complete mitochondrial cytochrome b sequences from all genera and nearly all recognized species. The families Geotriidae and Petromyzontidae are monophyletic, but the family Mordaciidae was resolved as two divergent lineages at the base of the tree. Within Petromyzontidae, the nonparasitic Lethenteron sp. S and Okkelbergia aepyptera were recognized as distinct lineages, Lethenteron morii and Lampetra zanandreai were moved to new genera, a sister species relationship was recovered between Caspiomyzon wagneri and Eudontomyzon hellenicus, and a clade was recovered inclusive of Entosphenus hubbsi and western North American Lampetra (L. ayresii and L. richardsoni). The placement of E. hellenicus as the sister species to C. wagneri reduces the number of genera comprised entirely of parasitic species to two, Geotria and Petromyzon. The recognition of distinct lineages for O. aepyptera and Lethenteron sp. S recognizes, for the first time, lineages comprised entirely of nonparasitic species. Apart from the results mentioned above, monophyly was supported for the multi-specific genera Entosphenus, Eudontomyzon, Ichthyomyzon, Lampetra (restricted to European species), and Lethenteron. Intergeneric relationships within Petromyzontidae were poorly resolved, but separate clades inclusive of Entosphenus and Tetrapleurodon (subfamily Entospheninae) and one comprised of Eudontomyzon, Lampetra, and Okkelbergia were recovered.

  • phylogeny of living parasitic lampreys petromyzontiformes based on morphological data
    Copeia, 2003
    Co-Authors: Howard S Gill, Claude B. Renaud, Francois Chapleau, Richard L. Mayden, I. C. Potter
    Abstract:

    Abstract Relationships among the 18 extant species of parasitic lamprey (Petromyzontiformes) were determined using a cladistic analysis of 32 mainly morphological characters. Because previous analyses support all known fossils as phylogenetically older or the same age as living lampreys, a composite agnathan fossil was used as an outgroup. A consensus of three equally parsimonious trees revealed a trichotomy between a monophyletic northern hemisphere clade and the southern hemisphere genera Geotria and Mordacia. The monophyletic status of the northern hemisphere lampreys and their classification in a single family Petromyzontidae was corroborated. It is suggested that the two southern hemisphere lamprey genera be retained as distinct families. Among northern hemisphere species, Ichthyomyzon and Petromyzon form a monophyletic group sister to the remaining genera. Caspiomyzon is sister to Tetrapleurodon + Entosphenus + Lethenteron + Eudontomyzon + Lampetra, with Tetrapleurodon in turn being sister to a grou...

  • the structure of mordacia mordax insulin supports the monophyly of the petromyzontiformes and an ancient divergence of mordaciidae and geotriidae
    Comparative Biochemistry and Physiology B, 2001
    Co-Authors: J. M. Conlon, Yuqi Wang, I. C. Potter
    Abstract:

    The phylogenetic relationships between the two southern hemisphere lamprey families (Geotriidae and Mordaciidae) and their northern hemisphere counterparts (Petromyzontidae) are unresolved. Insulin was isolated from an extract of islet-containing intestinal tissue from ammocoetes of the Australian lamprey, Mordacia mordax. Its primary structure was established as A-chain: GIVEQCCHRK10CSIYDMENYC20N and B-chain: SALMGTGGTH10LCGSHLVEAL20YVVCGQRGFF30 YTP[SKG]. Although the residues in parentheses are only tentatively assigned, mass spectrometry supports the proposed sequence and demonstrates that Mordacia proinsulin, unlike proinsulin from Geotria australis, is fully processed to mature insulin. Insulins from M. mordax and G. australis and from the northern hemisphere lampreys Petromyzon marinus and Lampetra fluviatilis share a pentapeptide extension to N-terminus of the B-chain (Ser-Ala-Leu-Xaa-Gly) that has never been found in the insulins of any other vertebrate class. This observation provides support for the claim that the Petromyzontiformes constitute a monophyletic group. M. mordax insulin differs from that of G. australis by 18 amino acid residues but by only four residues from the common sequence of P. marinus and L. fluviatilis insulin. These data are consistent with the view that Geotriidae and Mordaciidae have been separated for a long period and suggest that G. australis insulin has undergone an accelerated rate of molecular evolution.

Rex Meade Strange - One of the best experts on this subject based on the ideXlab platform.

  • Characterization and Evolution of Germ1, an Element that Undergoes Diminution in Lampreys (Cyclostomata: Petromyzontidae)
    Journal of Molecular Evolution, 2019
    Co-Authors: Rex Meade Strange, Landon L. Moore
    Abstract:

    The sea lamprey ( Petromyzon marinus ) undergoes substantial genomic alterations during embryogenesis in which specific sequences are deleted from the genome of somatic cells yet retained in cells of the germ line. One element that undergoes diminution in P. marinus is Germ1 , which consists of a somatically rare (SR) region and a fragment of 28S rDNA. Although the SR-region has been used as a marker for genomic alterations in lampreys, the evolutionary significance of its diminution is unknown. We examined the Germ1 element in five additional species of lamprey to better understand its evolutionary significance. Each representative species contained sequences similar enough to the Germ1 element of P. marinus to be detected via PCR and Southern hybridizations, although the SR-regions of Lampetra aepyptera and Lethenteron appendix are quite divergent from the homologous sequences of Petromyzon and three species of Ichthyomyzon . Lamprey Germ1 sequences have a number of features characteristic of the R2 retrotransposon, a mobile element that specifically targets 28S rDNA. Phylogenetic analyses of the SR-regions revealed patterns generally consistent with relationships among the species included in our study, although the 28S-fragments of each species/genus were most closely related to its own functional rDNA, suggesting that the two components of Germ1 were assembled independently in each lineage. Southern hybridizations showed evidence of genomic alterations involving Germ1 in each species. Our results suggest that Germ1 is a R2 retroelement that occurs in the genome of P. marinus and other petromyzontid lampreys, and that its diminution is incidental to the reduction in rDNA copies during embryogenesis.

  • First Report of a Mitochondrial Pseudogene in Agnathan Vertebrates (Cyclostomata: Petromyzontidae)
    Journal of Molecular Evolution, 2018
    Co-Authors: Rex Meade Strange, Kimberly J. Delaney
    Abstract:

    We report herein the characterization of a nuclear paralog of a fragment of the mitochondrial genome (a numt ) in two closely related species of lampreys ( Ichthyomyzon spp.). Although numts have been characterized in several vertebrate taxa, numts have yet to be reported for fishes in general. Given the phylogenetic position of lampreys relative to other vertebrates, the presence of numts within the lamprey genome is either evidence of an ancestral trait lost in other fishes but uniquely retained in agnathans and amniotes, or (more intriguingly) a product of the genome rearrangements these animals undergo during development.

  • The mitogenome of the southern Brook Lamprey, Ichthyomyzon gagei (Cyclostomata: Petromyzontidae).
    Mitochondrial DNA. Part B Resources, 2017
    Co-Authors: Rex Meade Strange, Vivian T. Truong, Kimberly Delaney
    Abstract:

    The southern brook lamprey (Ichthyomyzon gagei) is a non-parasitic lamprey endemic to the southeastern US. Here, we report the complete mitogenome of this basal vertebrate and found its genomic org...

Claude B. Renaud - One of the best experts on this subject based on the ideXlab platform.

  • Redescription of the Far Eastern brook lamprey Lethenteronreissneri (Dybowski, 1869) (Petromyzontidae).
    ZooKeys, 2015
    Co-Authors: Claude B. Renaud, Alexander M Naseka
    Abstract:

    Nonparasitic Lethenteron reissneri (Dybowski) is redescribed based on four syntypes (two adults and two ammocoetes) from the Onon and Ingoda rivers, Russia, and 15 topotypic specimens (seven metamorphosing ammocoetes and eight ammocoetes) from the Onon River system, Russia and Mongolia. Posterial teeth were not mentioned in the original description, but Berg (1931) stated that they were sometimes absent, which he later (Berg 1948) changed to usually absent, based on material (some of which we have re-identified as parasitic Lethenteron camtschaticum) from far outside of the type locality. The latter view has been widely accepted by subsequent authors. Unfortunately, the poor condition of the two adult syntypes did not permit verification of this character. However, a row of posterials was clearly visible in six of the seven topotypic metamorphosing ammocoetes and indicates their usual presence in the species. The first full description of the ammocoetes, including pigmentation, is provided. The present study restricts the distribution of Lethenteron reissneri to the Shilka and Songhua river systems within the Amur River basin, until a more geographically comprehensive study is undertaken. Additionally, in this study, feeding versus non-feeding at the adult stage, are considered to be valid taxonomic characters at the species level.

  • eudontomyzon graecus a new nonparasitic lamprey species from greece petromyzontiformes Petromyzontidae
    Zootaxa, 2010
    Co-Authors: Claude B. Renaud, Panos S. Economidis
    Abstract:

    Eudontomyzon graecus, sp. n., a nonparasitic lamprey from Greece, is restricted to the Louros River drainage, Ionian Sea basin, Epirus Periphery. It is distinguished from Eudontomyzon hellenicus, the other nonparasitic Greek brook lamprey, occurring allopatrically in the Strymon River drainage, Aegean Sea basin, Central Macedonia Periphery, by possessing at the adult stage a relatively longer tail and a greater number of bicuspid teeth in both the first row of anterials and posterials, and at the ammocoete stage, by a relatively shorter trunk and longer tail and a less pigmented upper lip, tongue precursor bulb and lateral aspects of the elastic ridge. Taken individually, these three adult and five larval characters, varied in their diagnostic power from 71 to 88% for the adults and from 91 to 97% for the ammocoetes. However, in combination, these characters provide sufficient evidence to justify recognition of this new species, in addition to the wide distance (ca 400 km) separating it from its closest extant relative, as well as its independent origin.

  • lethenteron ninae a new nonparasitic lamprey species from the north eastern black sea basin petromyzontiformes Petromyzontidae
    Zootaxa, 2009
    Co-Authors: Alexander M Naseka, Sako B Tuniyev, Claude B. Renaud
    Abstract:

    Lethenteron ninae sp. n., a nonparasitic lamprey, is described from rivers of western Transcaucasia in Russia and Abkhazia. It is distinguished from the other species of Lampetrinae in Europe and west Asia (Black Sea basin) by the combination of the following character states: adults with a dark blotch near the apex of the second dorsal fin; exolaterals absent; posterials either absent or more commonly present in a single incomplete row of 3–7 teeth (a toothless gap in the middle); transverse lingual lamina with 9–15 unicuspid teeth, the median one markedly enlarged; supraoral lamina with two unicuspid teeth separated by a toothless bridge; 1–2 rows of anterials, usually 2; first row of anterials with 5–7 unicuspid teeth; oral fimbriae, 69–99; trunk myomeres in both ammocoetes and adults, 56–62; and in ammocoetes, trunk not mottled and tongue precursor bulb clearly triangular, with a wide base and a pointed apex bearing few cirri.

  • novel relationships among lampreys petromyzontiformes revealed by a taxonomically comprehensive molecular data set
    Lang N.J. Roe K.J. Renaud C.B. Gill H.S. Potter I.C. Freyhof J. Naseka A.M. Cochran P. Pérez H.E. Habit E.M. Kuhajda B.R. Neely D.A. Reshetnikov Y.S. , 2009
    Co-Authors: Nicholas J Lang, Howard S Gill, Alexander M Naseka, Philip A Cochran, Hector Espinosa Perez, Evelyn Habit, Claude B. Renaud, Jorg Freyhof, I. C. Potter, Bernard R. Kuhajda
    Abstract:

    The systematics of lampreys was investigated using complete mitochondrial cytochrome b sequences from all genera and nearly all recognized species. The families Geotriidae and Petromyzontidae are monophyletic, but the family Mordaciidae was resolved as two divergent lineages at the base of the tree. Within Petromyzontidae, the nonparasitic Lethenteron sp. S and Okkelbergia aepyptera were recognized as distinct lineages, Lethenteron morii and Lampetra zanandreai were moved to new genera, a sister species relationship was recovered between Caspiomyzon wagneri and Eudontomyzon hellenicus, and a clade was recovered inclusive of Entosphenus hubbsi and western North American Lampetra (L. ayresii and L. richardsoni). The placement of E. hellenicus as the sister species to C. wagneri reduces the number of genera comprised entirely of parasitic species to two, Geotria and Petromyzon. The recognition of distinct lineages for O. aepyptera and Lethenteron sp. S recognizes, for the first time, lineages comprised entirely of nonparasitic species. Apart from the results mentioned above, monophyly was supported for the multi-specific genera Entosphenus, Eudontomyzon, Ichthyomyzon, Lampetra (restricted to European species), and Lethenteron. Intergeneric relationships within Petromyzontidae were poorly resolved, but separate clades inclusive of Entosphenus and Tetrapleurodon (subfamily Entospheninae) and one comprised of Eudontomyzon, Lampetra, and Okkelbergia were recovered.

  • Petromyzontidae, Entosphenus tridentatus : southern distribution record, Isla Clarión, Revillagigedo Archipelago, Mexico
    Check List, 2008
    Co-Authors: Claude B. Renaud
    Abstract:

    The purpose of this note is to document the southernmost record of Pacific lamprey, Entosphenus tridentatus, off the coast of Mexico. The scientific name of this species is in a state of flux. The American Fisheries Society names list (Nelson et al. 2004) gives Lampetra tridentata; however, Nelson (2006) subsequently accepted Entosphenus tridentatus based on the phylogenetic study of Gill et al. (2003), which was not available to the AFS Names Committee in time for it to make an evaluation prior to publication. The AFS Names Committee is currently evaluating this new evidence for its next list scheduled for publication in 2010 (J. S. Nelson, personal communication, 2007).

Neil J. Gemmell - One of the best experts on this subject based on the ideXlab platform.

  • The Southern Hemisphere lampreys (Geotriidae and Mordaciidae)
    Reviews in Fish Biology and Fisheries, 2021
    Co-Authors: Allison K. Miller, Cindy Baker, Jane C. Kitson, Jonah L. Yick, Pedro E. Inalaf Manquel, Alana Alexander, Neil J. Gemmell
    Abstract:

    Lampreys are jawless fishes (Cyclostomata) that are distributed antitropically around the world. Of the three extant lamprey clades (Petromyzontidae, Geotriidae, and Mordaciidae), Geotriidae and Mordaciidae are only found in the Southern Hemisphere. Geotriidae includes two anadromous species, G. australis and G. macrostoma , while Mordaciidae includes three species: Mordacia mordax (anadromous), M. lapicida (anadromous), and M. praecox (resident and non-feeding). Similar to several Northern Hemisphere species, Southern Hemisphere species are targeted by fisheries ( G. australis ), culturally significant (to Māori and Mapuche), key prey for many species (including endangered species), and regarded as crucial links for understanding the evolution of vertebrates. Prior to this work, key information on the Southern Hemisphere lampreys was dispersed throughout the literature, hindering attempts to synthesise critical information about these species. Here we provide detailed descriptions of the five Southern Hemisphere species to facilitate the identification efforts by technicians, managers, researchers, and other interested parties. We then review the taxonomy, distribution, biology, genetics, significance, and threats to these lampreys from over 100 years of written sources (e.g., peer-reviewed publications and agency reports), complemented by interviews and Indigenous knowledge, in order to synthesise and centralise key information. We conclude by identifying Western science knowledge gaps and offering suggestions for addressing them: this is critical as anthropogenic environmental changes are negatively affecting Southern Hemisphere lampreys, and will likely continue to do so into the future.

Claudia Gérard - One of the best experts on this subject based on the ideXlab platform.

  • Metazoan parasite communities in Alosa alosa (Linnaeus, 1758) and Alosa fallax (Lacépède, 1803) (Clupeidae) from North-East Atlantic coastal waters and connected rivers
    Parasitology Research, 2017
    Co-Authors: Claudia Gérard, Maxime Hervé, Odile Bourgau, Eric Feunteun, Anthony Acou, Elodie Réveillac
    Abstract:

    Metazoan parasites were studied in 96 Alosa alosa and 78 Alosa fallax from North-East Atlantic coastal waters and connected rivers (among them three sympatric sites) in order to increase knowledge on these anadromous endangered fish and measure the parasitic impact on host condition. All shads were infected by one to six metazoan parasite taxa among the 12 identified in the whole sampling, with a mean abundance of parasites higher for A. alosa (167 ± 10) than for A. fallax (112 ± 11). Helminths, mostly trophically transmitted, were the best represented (eight taxa, prevalence up to 99%) in contrast with crustaceans and Petromyzontidae that rarely occurred (four taxa, prevalence

  • Petromyzon marinus (Petromyzontidae), an unusual host for helminth parasites in western Europe
    Diseases of Aquatic Organisms, 2015
    Co-Authors: Claudia Gérard, Véronique Verrez-bagnis, Marc Jerome, Emilien Lasne
    Abstract:

    The sea lamprey Petromyzon marinus, which is among the most phylogenetically ancient vertebrates, is a hematophagous ectoparasite that feeds on vertebrates and is considered vulnerable in Europe but is a pest in the North American Great Lakes. We conducted a literature review of helminth parasites of Petromyzon marinus and investigated postmetamorphic lampreys sampled in rivers and northeast Atlantic coastal waters (western France) during spawning migration. Based on the literature review, 16 helminth taxa have been recorded in Petromyzon marinus, among them 14 in North America but only 2 in Europe, with no species in common between these areas. Specific parasites are lacking, and helminth parasites recorded in Petromyzon marinus are mostly opportunistic and are trophically transmitted to fish hosts with both extremely low prevalence and mean intensity. Thus, Petromyzon marinus seems an unusual host that is probably infected through accidental ingestion of parasites by microphagous larvae (ammocoetes) and/or hematophagous postmetamorphs. Our field study supports this hypothesis, since only a single third-stage larva of Anisakis simplex sensu stricto was found in 2 postmetamorphic Petromyzon marinus among the 115 individuals dissected. This opportunistic, trophically transmitted, and cosmopolitan nematode species has never been recorded in North American sea lampreys and only once in Galician rivers (southern Europe). Infestation pathways of Petromyzon marinus by A. simplex are proposed vis-a-vis the feeding strategy of post-metamorphs and fish host species which potentially harbor anisakid larvae in their musculature. More generally, the complexity of biotic interactions is discussed considering Petromyzon marinus both as a host for helminth parasites and as a parasite for hosts such as fish and mammals, which are also potential predators of sea lamprey.

  • Petromyzon marinus (Petromyzontidae), an unusual host for helminth parasites in Western Europe
    Diseases of Aquatic Organisms, 2015
    Co-Authors: Claudia Gérard, Véronique Verrez-bagnis, Marc Jerome, Emilien Lasne
    Abstract:

    The sea lamprey Petromyzon marinus, which is among the most phylogenetically ancient vertebrates, is a hematophagous ectoparasite that feeds on vertebrates and is considered vulnerable in Europe but is a pest in the North American Great Lakes. We conducted a literature review of helminth parasites of P. marinus and investigated postmetamorphic lampreys sampled in rivers and northeast Atlantic coastal waters (western France) during spawning migration. Based on the literature review, 16 helminth taxa have been recorded in P. marinus, among them 14 in North America but only 2 in Europe, with no species in common between these areas. Specific parasites are lacking, and helminth parasites recorded in P. marinus are mostly opportunistic and are trophically transmitted to fish hosts with both extremely low prevalence and mean intensity. Thus, P. marinus seems an unusual host that is probably infected through accidental ingestion of parasites by microphagous larvae (ammocoetes) and/or hematophagous postmetamorphs. Our field study supports this hypothesis, since only a single third-stage larva of Anisakis simplex sensu stricto was found in 2 postmetamorphic P. marinus among the 115 individuals dissected. This opportunistic, trophically transmitted, and cosmopolitan nematode species has never been recorded in North American sea lampreys and only once in Galician rivers (southern Europe). Infestation pathways of P. marinus by A. simplex are proposed vis-à-vis the feeding strategy of postmetamorphs and fish host species which potentially harbor anisakid larvae in their musculature. More generally, the complexity of biotic interactions is discussed considering P. marinus both as a host for helminth parasites and as a parasite for hosts such as fish and mammals, which are also potential predators of sea lamprey.