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Since its description from the Galapagos Rift in the mid-1980s, Archinome rosacea has been recorded at hydrothermal vents in the Pacific, Atlantic and Indian Oceans. Only recently was a second species described from the Pacific Antarctic Ridge. We inferred the identities and evolutionary relationships of Archinome representatives sampled from across the hydrothermal vent range of the genus, which is now extended to cold methane seeps. Species delimitation using mitochondrial cytochrome c oxidase subunit I (COI) recovered up to six lineages, whereas concatenated datasets (COI, 16S, 28S and ITS1) supported only four or five of these as clades. Morphological approaches alone were inconclusive to verify the identities of species owing to the lack of discrete diagnostic characters. We recognize five Archinome species, with three that are new to science. The new species, designated based on molecular evidence alone, include: Archinome levinae n. sp., which occurs at both vents and seeps in the east Pacific, Archinome tethyana n. sp., which inhabits Atlantic vents and Archinome jasoni n. sp., also present in the Atlantic, and whose distribution extends to the Indian and southwest Pacific Oceans. Biogeographic connections between vents and seeps are highlighted, as are potential evolutionary links among populations from vent fields located in the east Pacific and Atlantic Oceans, and Atlantic and Indian Oceans; the latter presented for the first time.

A remarkable diversity of life history strategies, geographic distributions, and morphological characters provide a rich substrate for investigating the evolutionary relationships of arhynchobdellid leeches. The phylogenetic relationships, using parsimony analysis, of the order Arhynchobdellida were investigated using nuclear 18S and 28S rDNA, mitochondrial 12S rDNA, and cytochrome c oxidase subunit I sequence data, as well as 24 morphological characters. Thirty-nine arhynchobdellid species were selected to represent the seven currently recognized families. Sixteen rhynchobdellid leeches from the families Glossiphoniidae and Piscicolidae were included as outgroup taxa. Analysis of all available data resolved a single most-parsimonious tree. The cladogram conflicted with most of the traditional classification schemes of the Arhynchobdellida. Monophyly of the Erpobdelliformes and Hirudiniformes was supported, whereas the families Haemadipsidae, Haemopidae, and Hirudinidae, as well as the genera Hirudo or Aliolimnatis, were found not to be monophyletic. The results provide insight on the phylogenetic positions for the taxonomically problematic families Americobdellidae and Cylicobdellidae, the genera Semiscolex, Patagoniobdella, and Mesobdella, as well as genera traditionally classified under Hirudinidae. The evolution of dietary and habitat preferences is examined.

This study revises the taxonomic status of the formerly monotypic Archinomidae, which is nested within paraphyletic Amphinomidae according to recent phylogenetic work. We focused our taxonomic sampling to evaluate the affinities of Notopygos and genera classified as 'fusiform' in body shape, including Archinome and Chloeia. Prior to this study, the phylogenetic placement of Notopygos had not been evaluated. We inferred the phylogenetic relationships of Notopygos within Amphinomidae based on nuclear and mitochondrial markers, and cytochrome c oxidase subunit I genetic divergences of five Notopygos species, including the newly described Notopygos kekooa sp. n. from the Gulf of California. The phylogenetic and morphological evidence, now including Notopygos species, justified the establishment of two subfamilies within Amphinomidae. In accordance with ICZN Article 36 (Principle of Coordination), both subfamilies are presented as status novus in the nomenclature ranks. [ABSTRACT FROM AUTHOR]

Borda, E., Kudenov, J.D., Bienhold, C. & Rouse, G.W. (2012). Towards a revised Amphinomidae (Annelida, Amphinomida): description and affinities of a new genus and species from the Nile Deep-sea Fan, Mediterranean Sea. - Zoologica Scripta, 41, 307-325. The discovery of a new amphinomid species from wood falls deployed near cold seeps (1694 m) at the Nile Deep-sea Fan (Mediterranean Sea) highlights the need to revise Amphinomidae to better characterize amphinomid diversity. The phylogenetic affinities of the new amphinomid and 12 other species from nine Amphinomida genera were inferred using data from two nuclear (18S rDNA and 28S rDNA) and two mitochondrial (COI and 16S rDNA) genes. The phylogenetic analyses indicated a close relationship of the new species with other amphinomids associated with temporary pelagic substrata, including Amphinome sensu stricto (emended herein) and Hipponoa. The new species belongs to a distinct lineage and we, here, erect a new genus to accommodate it. Cryptonome gen. n. is the second amphinomid genus established for species from chemosynthetic environments. Cryptonome conclava sp. n. is distinguished morphologically from all previously described rectilinear Amphinomidae by lacking notochaetal hooks, having a reduced caruncle, modified neurochaetae and branchiae on nearly all segments. Taxonomic issues regarding amphinomid species presently assigned to Amphinome and the erroneous placement of related xylophylic taxa in Eurythoe are also outlined. We emend and restrict the five known oceanic flotsam species with stalked heart-shaped caruncles to Amphinome sensu stricto. An additional 15 species previously assigned to Amphinome may belong to other genera (e.g. Linopherus) and are here tentatively considered incertae sedis. Finally, Eurythoe turcica and Eurythoe parvecarunculata are transferred to Cryptonome gen. n. as new combinations. A revised key to a subset of rectilinear amphinomid genera (relevant to this study) is presented. [ABSTRACT FROM AUTHOR]

Abstract: A scourge of tropical and subtropical jungles, bloodfeeding terrestrial leeches of Haemadipsidae have long confused systematists and defied sensible biogeographic interpretation. The family Haemadipsidae usually includes problematic taxa that neither fit the typical IndoPacific distribution of the group, nor properly match diagnostic characters used to define the family. Historically, four additional families—Xerobdellidae, Diestecostomatidae Mesobdellidae and Nesophilaemonidae—have occasionally been recognized for New World and European representatives, though agreement on the composition of those families has not been consistent. Here, we expand the phylogenetic sampling of non-IndoPacific (among other) genera to include Meso American Diestecostoma species and Nesophilaemon skottsbergii from the Juan Fernandez Archipelago in order to critically assess prior hypotheses in a molecular phylogenetic analysis of arhynchobdellid leeches. The result, based on nuclear 18S rDNA and 28S rDNA and mitochondrial COI indicates that there are two distantly related lineages of bloodfeeding terrestrial leeches. The otherwise monophyletic family Haemadipsidae is found to exclude species of Xerobdella, Mesobdella and Diestecostoma. Xerobdellidae is formally resurrected to accommodate species of those three genera. Morphological characteristics corroborate the distinction of Haemadipsidae and Xerobdellidae on the basis of sexual and nephridial characters. Idiobdella seychellensis belongs in Haemadipsidae notwithstanding its lacking respiratory auricles. Nesophilaemon skottsbergii too is in Haemadipsidae notwithstanding its geographic proximity to the xerobdellid Mesobdella gemmata. The characters used to define haemadipsoid families are reevaluated. Feeding preferences and biogeographic patterns are also examined. [Copyright &y& Elsevier]

The relationships, as well as identification of species, within Helobdella (Glossiphoniidae) were explored through phylogenetic analysis and through an overview of the historical systematics of the genus. The phylogeny was determined using morphological data and the mitochondrial gene sequences of cytochrome c oxidase subunit I and nicotinamide adenine dinucleotide dehydrogenase subunit I. A broad representation of 15 ingroup species was sampled, including 10 individuals from South America. Outgroup taxa included five species of Haementeria . Cladistic analysis of all available data resulted in one most parsimonious tree. Results shed light on genetic divergence of members classified as the same species, including those that are not monophyletic. Historically, external morphological characters have played a significant role in contributing to the confusion in the classification of H. triserialis, H. papillata, H. lineata and H. fusca in North America. Re-evaluation of Verril's Clepsine papillifera var. b and var. d in a phylogenetic context provides a solution. Additionally, the genera Adaetobdella, Acritobdella, Dacnobdella and Gloiobdella created by Ringuelet are returned to Helobdella based on overlapping morphological characters. [ABSTRACT FROM AUTHOR]