Spermiogenesis and spermatozoal ultrastructure in Trichomycteridae (Teleostei: Ostariophysi: Siluriformes)

Spadella, M.A., Oliveira, C. and Quagio‐Grassiotto, I. 2009. Spermiogenesis and spermatozoal ultrastructure in Trichomycteridae (Teleostei: Ostariophysi: Siluriformes). —Acta Zoologica (Stockholm) 91 : 373–389. Siluriformes comprises the most diverse and widely distributed ostariophysan group, a fish assemblage that includes about three quarters of the freshwater fish of the world. In this study, the ultrastructural characterization of spermiogenesis and spermatozoa in specimens of Copionodontinae (the sister group to all other trichomycterids), Trichomycterinae (a derived trichomycterid group), and Ituglanis (a genus not assigned to any trichomycterid subfamily) is presented. The comparative analyses of the data show that trichomycterid species share six of seven analyzed spermiogenesis characters, reinforcing the monophyly of the group. Analyses of trichomycterid sperm ultrastructure showed that the species studied share the same character states for nine of seventeen characters analyzed. Copionodon orthiocarinatus and Ituglanis amazonicus each share more ultrastructural characters with species of Trichomycterus than with one another. Regarding the families of Loricarioidea, the species of Trichomycteridae share more characters of spermatogenesis, spermiogenesis, and sperm with representatives of the families Callichthyidae, Loricariidae, and Scoloplacidae than with Nematogenyidae, its hypothesized sister group. With the exception of the family Nematogenyidae, the character similarities observed reinforce the monophyly of the superfamily Loricarioidea.     

A molecular phylogeny of fleas (Insecta: Siphonaptera): origins and host associations

Siphonaptera (fleas) is a highly specialized order of holometabolous insects comprising ～2500 species placed in 16 families. Despite a long history of extensive work on flea classification and biology, phylogenetic relationships among fleas are virtually unknown. We present the first formal analysis of flea relationships based on a molecular matrix of four loci (18S ribosomal DNA, 28S ribosomal DNA, Cytochrome Oxidase II, and Elongation Factor 1‐alpha) for 128 flea taxa from around the world representing 16 families, 25 subfamilies, 26 tribes, and 83 flea genera with eight outgroups. Trees were reconstructed using direct optimization and maximum likelihood techniques. Our analysis supports Tungidae as the most basal flea lineage, sister group to the remainder of the extant fleas. Pygiopsyllomorpha is monophyletic, as are the constituent families Lycopsyllidae, Pygiopsyllidae, and Stivaliidae, with a sister group relationship between the latter two families. Macropsyllidae is resolved as sister group to Coptopsyllidae with moderate nodal support. Stephanociricidae is monophyletic, as are the two constituent subfamilies Stephanocircinae and Craneopsyllinae. Vermipsyllidae is placed as sister group to Jordanopsylla. Rhopalopsyllidae is monophyletic as are the two constituent subfamilies Rhopalopsyllinae and Parapsyllinae. Hystrichopsyllidae is paraphyletic with Hystrichopsyllini placed as sister to some species of Anomiopsyllini and Ctenopariini placed as sister to Carterettini. Ctenophthalmidae is grossly paraphyletic with the family broken into seven lineages dispersed on the tree. Most notably, Anomiopsyllini is paraphyletic. Pulicidae and Chimaeropsyllidae are both monophyletic and these families are sister groups. Ceratophyllomorpha is monophyletic and includes Ischnopsyllidae, Ceratophyllidae, and Leptopsyllidae. Leptopsyllidae is paraphyletic as are its constituent subfamilies Amphipsyllinae and Leptopsyllinae and the tribes Amphipsyllini and Leptopsyllini. Ischnopsyllidae is monophyletic. Ceratophyllidae is monophyletic, with a monophyletic Dactypsyllinae nested within Ceratophyllinae, rendering the latter group paraphyletic. Mapping of general host associations on our topology reveals an early association with mammals with four independent shifts to birds. © The Willi Hennig Society 2008.     

Molecular phylogeny of the Valvatacea (Asteroidea: Echinodermata)

The Valvatacea is one the most ecologically important, taxonomically diverse, and widespread groups of post‐Palaeozoic (i.e. modern) Asteroidea. Classification within the group has been historically problematic. We present a comprehensively sampled, three‐gene (12S, 16S, early‐stage histone H3) molecular phylogenetic analysis of the Valvatacea. We include five of the six families within the Paxillosida, the monotypic Notomyotida, and 13 of the 16 families of the living Valvatida. The Solasteridae is removed from the Velatida (Spinulosacea) and joins the Ganeriidae and the Leilasteridae as members of the clade containing the Asterinidae. The Poraniidae is supported as the sister group to the large cluster of Valvatacea. Asteropseids and poraniids are phylogenetically distant, contrary to morphological evidence. Several goniasterid‐like ophidiasterids, such as Fromia and Neoferdina are supported as derived goniasterids rather than as Ophidiasteridae. The Benthopectinidae (Notomyotida) are supported as members of the Paxillosida as are two members of the Pseudarchasterinae that have traditionally been considered members of the Goniasteridae. Our data suggest that Antarctic valvataceans may be derived from sister taxa in adjacent regions. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 161 , 769–788.     

Cladistic analysis of Neuroptera and their systematic position within Neuropterida (Insecta: Holometabola: Neuropterida: Neuroptera)

A phylogenetic analysis of Neuroptera using thirty‐six predominantly morphological characters of adults and larvae is presented. This is the first computerized cladistic analysis at the ordinal level. It included nineteen species representing seventeen families of Neuroptera, three species representing two families (Sialidae and both subfamilies of Corydalidae) of Megaloptera, two species representing two families of Raphidioptera and as prime outgroup one species of a family of Coleoptera. Ten equally most parsimonious cladograms were found, of which one is selected and presented in detail. The results are discussed in light of recent results from mental phylogenetic cladograms. The suborders Nevrorthi‐ formia, Myrmeleontiformia and Hemerobiiformia received strong support, however Nevrorthiformia formed the adelphotaxon of Myrmeleontiformia + Hemerobiiformia (former sister group of Myrmeleontiformia only). In Myrmeleontiformia, the sister‐group relationships between Psychopsidae + Nemopteridae and Nymphidae + (Myrmeleontidae + Ascalaphidae) are corroborated. In Hemerobiiformia, Ithonidae + Polystoechotidae is confirmed as the sister group of the remaining families. Dilaridae + (Mantispidae + (Rhachiberothidae + Berothidae)), which has already been proposed, is confirmed. Chrysopidae + Osmylidae emerged as the sister group of a clade comprising Hemerobiidae + ((Coniopterygidae + Sisyridae) + (dilarid clade)). Despite the sister‐group relationship of Coniopterygidae + Sisyridae being only weakly supported, the position of Coniopterygidae within the higher Hemerobiiformia is corroborated. At the ordinal level, the analysis provided clear support for the hypothesis that Megaloptera + Neuroptera are sister groups, which upsets the conventional Megaloptera + Raphidioptera hypothesis.     

The systematic position of Meruidae (Coleoptera, Adephaga) and the phylogeny of the smaller aquatic adephagan beetle families

A phylogenetic analysis of Adephaga is presented. It is based on 148 morphological characters of adults and larvae and focussed on a placement of the recently described Meruidae, and the genus‐level phylogeny of the smaller aquatic families Gyrinidae, Haliplidae and Noteridae. We found a sister group relationship between Gyrinidae and the remaining adephagan families, as was found in previous studies using morphology. Haliplidae are either the sister group of Dytiscoidea or the sister group of a clade comprising Geadephaga and the dytiscoid families. Trachypachidae was placed as the sister group of the rhysodid‐carabid clade or of Dytiscoidea. The monophyly of Dytiscoidea including Meru is well supported. Autapomorphies are the extensive metathoracic intercoxal septum, the origin of the metafurca from this structure, the loss of Mm. furcacoxalis anterior and posterior, and possibly the presence of an elongated subcubital setal binding patch. Meruidae was placed as sister group of the Noteridae. Synapomorphies are the absence of the transverse ridge of the metaventrite, the fusion of abdominal segments III and IV, the shape of the strongly asymmetric parameres, and the enlargement of antennomeres 5, 7 and 9. The Meru‐noterid clade is the sister group of the remaining Dytiscoidea. The exact position of Aspidytes within this clade remains ambiguous: it is either the sister group of Amphizoidae or the sister group of a clade comprising this family and Hygrobiidae + Dytiscidae. The sister group relationship between Spanglerogyrinae and Gyrininae was strongly supported. The two included genera of Gyrinini form a clade, and Enhydrini are the sister group of a monophylum comprising the remaining Enhydrini and Orectochilini. A branching pattern (Peltodytes + (Brychius + Haliplus)) within Haliplidae was confirmed. Algophilus, Apteraliplus and the Haliplus‐subgenus Liaphlus form a clade. The generic status of the two former taxa is unjustified. The Phreatodytinae are the sister group of Noterinae, and Notomicrus (+ Speonoterus), Hydrocoptus, and Pronoterus branch off successively within this subfamily. The search for the larvae of Meru and a combined analysis of morphological and molecular data should have high priority. © The Willi Hennig Society 2006.     

Inclusion of rare taxa from Blattidae and Anaplectidae improves phylogenetic resolution in the cockroach superfamily Blattoidea

Cockroaches are an ecologically and economically important insect group, but some fundamental aspects of their evolutionary history remain unresolved. In particular, there are outstanding questions about some of the deeper relationships among cockroach families. As a group transferred from Blaberoidea Saussure to Blattoidea Latreille, the evolutionary history of the family Anaplectidae Walker requires re-evaluation. In our study, we infer the phylogeny of Blattoidea based on the mitochondrial genomes of 28 outgroup taxa and 67 ingroup taxa, including 25 newly sequenced blattoid species mainly from the families Anaplectidae and Blattidae Latreille. Our results indicate that Blattoidea is the sister group of the remaining Blattodea Brunner von Wattenwyl and that Blattoidea can be divided into three main clades: Blattidae + Tryonicidae McKittrick & Mackerras, Lamproblattidae McKittrick + Anaplectidae and Termitoidae Latreille + Cryptocercidae Handlirsch. Our analyses provide robust support for previously uncertain hypotheses. The sister group of Termitoidae + Cryptocercidae (Xylophagodea Engel) is inferred to constitute the rest of Blattoidea, for the first time. Within Blattidae, Hebardina Bey-Bienko is placed as the sister lineage to the rest of Blattidae. The subfamily Archiblattinae is polyphyletic, Blattinae is paraphyletic and Polyzosteriinae is monophyletic (Macrocercinae Roth not included); the genus Periplaneta Burmrister is polyphyletic. Based on the results of our phylogenetic analyses, we have revised these taxa. A new subfamily, Hebardininae subfam.nov. , is proposed in Blattidae. Archiblattinae and Shelfordella Adelung are synonymized with Blattinae and Periplaneta, respectively: Archiblattinae Kirby syn.nov. and Shelfordella Adelung syn.nov. Our inferred divergence times indicate that Blattoidea emerged in the Late Triassic, with six families in Blattoidea diverging in the Middle and Late Jurassic. We suggest that the divergences among lineages of Asian Blattidae and Anaplectidae were driven by the uplift of the Himalayas and deglaciation during the Quaternary, leading to the present-day distributions of these taxa.     

Limb myology and phylogenetic relationships in the superfamily Dipodoidea (birch mice, jumping mice, and jerboas)

Limb muscles were dissected in seven genera, representing all six superfamilies, of dipodoid rodents and myoloic characters were used to construct a phylogenetic hpothesis of relationships within this cfade. Mologic differences among genera suported tie monophyly of the superfamily Dipodoidea reLtive to the outrou taxon and reveaEd thatSicista is the sister group to all other zapodid and dipodid enera. Tkis picement of Sicista differs markedly from its position in previous classifications where it has been regarded merely as a primitive zapodid genus. The phlograrn based on rnyologic characters also indicated that Cardiocranius is not a rimitive dipodid genus; it is the sister group to the subfamily Dipodinae. Although myologic differences among taxa were not sufficient to warrant the continued separation of zaodids and dipodids into two families, a new classification that places Sicista in its own family, ficistidae, and places the remaining zaodids and dipodids in the family Dipodidae, is proposed. Differences in karyology, genitaP morholoy, and postcranial osteological characters among dipodoid rodents are discussed in light or this pjylogeny.     

Examination of unidentifiable spined loach individuals found in the overlap zone of two tetraploid species within a single river in Japan

An endangered tetraploid spined loach species, Cobitis takenoi (Cypriniformes: Cobitidae; hereafter called Tango loach) is known to inhabit only a single river in Kyoto Prefecture, Japan. Since Tango loach was discovered recently, in 2010, and only described in 2016, its morphology, ecology, and genetics are not well studied. Another tetraploid spined loach species Cobitis sp. BIWAE type A (hereafter, called Ohshima loach) inhabits the same river. The two loaches are reported as morphologically distinguishable from each other. Although the habitats of the two species in the river are segregated (Ohshima loach and Tango loach inhabit the upper and lower reaches, respectively), they overlap to a small degree in the boundary area. Recently, some individuals with morphological characteristics that are intermediate between the two species were found in the overlap zone. It was suspected that hybrids between the two species were produced since breeding seasons of the two species overlapped. To investigate whether the two species produce hybrids, we performed mitochondrial and nuclear DNA analyses on the unidentifiable individuals. Eight individuals unidentifiable to the species level collected in the river between 2017 and 2018 were examined and compared with the Tango and Ohshima loach species. Using mitochondrial DNA (mtDNA) cytochrome b analysis, we found that six individuals had mtDNA types identical to Tango loach and two individuals had mtDNA types identical to Ohshima loach. Furthermore, sequencing analysis of nuclear recombination activating gene 1 (RAG-1) revealed that each species had species-specific alleles. The phylogenetic analysis indicated that alleles in Tango loach were divided into two clusters and those from Ohshima loach formed a single cluster. There were no discrepancies in the combination between mtDNA and nuclear DNA species types within each specimen. DNA fingerprinting analysis (AFLP) showed that the species-unidentifiable individuals exhibited distinctly segregated genetic groups corresponding with Tango and Ohshima loaches. In summary, no hybrids were detected from among any unidentifiable individual examined in this study. New conventional genetic method for discriminating the two sympatric loach species developed here can be effective tool for the conservation of the Tango loach since there was no strict diagnostic morphological character between them.     

Relationships in theAcanthaceae and related families as suggested by cladistic analysis ofrbcL nucleotide sequences

A parsimony analysis of DNA sequences of the chloroplast-encoded generbcL from twelve members of theAcanthaceae s.l., including members of the sometimes segregateThunbergioideae andNelsonioideae, and other families in theBignoniales sensuThorne (1992) is presented. The results largely agree with the classification of theAcanthaceae presented byBremekamp (1965) andThorne (1992) and supportNelsonioideae as a sister group to the rest of theAcanthaceae. Thunbergioideae are placed as a sister toAcanthaceae s.str.Acanthus andAphelandra, both representatives ofAcanthoideae, form a sister group toRuellioideae. An analysis of branch support found that many branches throughout theBignoniales are weakly upheld. This points to the need for further studies in the group using more sequences ofrbcL as well as other data. None of the families ofBignoniales as presently circumscribed (includingAcanthaceae s.l.) were strongly supported, although the larger clade containing the families of theBignoniales was robust.     

The phylogeny of termites (Dictyoptera: Isoptera) based on mitochondrial and nuclear markers: Implications for the evolution of the worker and pseudergate castes, and foraging behaviors

A phylogenetic hypothesis of termite relationships was inferred from DNA sequence data. Seven gene fragments (12S rDNA, 16S rDNA, 18S rDNA, 28S rDNA, cytochrome oxidase I, cytochrome oxidase II and cytochrome b) were sequenced for 40 termite exemplars, representing all termite families and 14 outgroups. Termites were found to be monophyletic with Mastotermes darwiniensis (Mastotermitidae) as sister group to the remainder of the termites. In this remainder, the family Kalotermitidae was sister group to other families. The families Kalotermitidae, Hodotermitidae and Termitidae were retrieved as monophyletic whereas the Termopsidae and Rhinotermitidae appeared paraphyletic. All of these results were very stable and supported with high bootstrap and Bremer values. The evolution of worker caste and foraging behavior were discussed according to the phylogenetic hypothesis. Our analyses suggested that both true workers and pseudergates (“false workers”) were the result of at least two different origins. Our data support a traditional hypothesis of foraging behavior, in which the evolutionary transition from a one-piece type to a separate life type occurred through an intermediate behavioral form.     

Production of a mutant of large-scale loach Paramisgurnus dabryanus with skin pigmentation loss by genome editing with CRISPR/Cas9 system

CRISPR/Cas9 system has been developed as a highly efficient genome editing technology to specifically induce mutations in a few aquaculture species. In this study, we described induction of targeted gene (namely tyrosinase, tyr) mutations in large-scale loach Paramisgurnus dabryanus, an important aquaculture fish species and a potential model organism for studies of intestinal air-breathing function, using the CRISPR/Cas9 system. Tyr gene in large-scale loach was firstly cloned and then its expressions were investigated. Two guide RNAs (gRNAs) were designed and separately transformed with Cas9 in the loach. 89.4% and 96.1% of injected loach juveniles respectively displayed a graded loss of pigmentation for the two gRNAs, in other words, for target 1 and target 2. We classified the injected loach juveniles into five groups according to their skin color phenotypes, including four albino groups and one wild-type-like group. And one of them was clear albino group, which was of high ornamental and commercial value. More than 50 clones for each albino transformant with a visible phenotype in each target were randomly selected and sequenced. Results obtained here showed that along with the increase of pigmentation, wild-type alleles appeared in the injected loach juveniles more often and insertion/deletion alleles less frequently. This study demonstrated that CRISPR/Cas9 system could be practically performed to modify large-scale loach tyr to produce an albino mutant of high ornamental and commercial value, and for the first time showed successful use of the CRISPR/Cas9 system for genome editing in a Cobitidae species.

     

Phylogenetic analyses of Malpighiales using plastid and nuclear DNA sequences, with particular reference to the embryology of Euphorbiaceae sens. str.

We present phylogenetic analyses of Malpighiales, which are poorly understood with respect to relationships within the order, using sequences from rbcL, atpB, matK and 18SrDNA from 103 genera in 23 families. From several independent and variously combined analyses, a four-gene analysis using all sequence data provided the best resolution, resulting in the single most parsimonious tree. In the Malpighiales [bootstrap support (BS) 100%], more than eight major clades comprising a family or group of families successively diverged, but no clade containing more than six families received over 50% BS. Instead, ten terminal clades that supported close relationships between and among families (>50% BS) were obtained, between, for example, Balanopaceae and Chrysobalanaceae; Lacistemataceae and Salicaceae; and Phyllanthaceae and Picrodendraceae. The monophyly of Euphorbiaceae sens. str. were strongly supported (BS 100%), but its sister group was unclear. Euphorbiaceae sens. str. comprised two basally diverging clades (BS 100%): one leading to the Clutia group (Chaetocarpus, Clutia, Pera and Trigonopleura), and the other leading to the rest of the family. The latter shared a palisadal, instead of a tracheoidal exotegmen as a morphological synapomorphy. While both Acalyphoideae (excluding Dicoelia and the Clutia group) and Euphorbioideae are monophyletic, Crotonoideae were paraphyletic, requiring more comprehensive analyses.     

A global phylogeny of apple snails: Gondwanan origin, generic relationships, and the influence of outgroup choice (Caenogastropoda: Ampullariidae)

Apple snails (Ampullariidae) are a diverse family of pantropical freshwater snails and an important evolutionary link to the common ancestor of the largest group of living gastropods, the Caenogastropoda. A clear understanding of relationships within the Ampullariidae, and identification of their sister taxon, is therefore important for interpreting gastropod evolution in general. Unfortunately, the overall pattern has been clouded by confused systematics within the family and equivocal results regarding the family's sister group relationships. To clarify the relationships among ampullariid genera and to evaluate the influence of including or excluding possible sister taxa, we used data from five genes, three nuclear and two mitochondrial, from representatives of all nine extant ampullariid genera, and species of Viviparidae, Cyclophoridae, and Campanilidae, to reconstruct the phylogeny of apple snails, and determine their affinities to these possible sister groups. The results obtained indicate that the Old and New World ampullariids are reciprocally monophyletic with probable Gondwanan origins. All four Old World genera, Afropomus, Saulea, Pila, and Lanistes, were recovered as monophyletic, but only Asolene, Felipponea, and Pomella were monophyletic among the five New World genera, with Marisa paraphyletic and Pomacea polyphyletic. Estimates of divergence times among New World taxa suggest that diversification began shortly after the separation of Africa and South America and has probably been influenced by hydrogeological events over the last 90 Myr. The sister group of the Ampullariidae remains unresolved, but analyses omitting certain outgroup taxa suggest the need for dense taxonomic sampling to increase phylogenetic accuracy within the ingroup. The results obtained also indicate that defining the sister group of the Ampullariidae and clarifying relationships among basal caenogastropods will require increased taxon sampling within these four families, and synthesis of both morphological and molecular data. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 98 , 61–76.     

Molecular phylogeny of cockroaches (Blattaria) based on mitochondrial COII gene sequences

Phylogenetic relationships among five cockroach families (Cryptocercidae, Polyphagidae, Blattidae, Blattellidae and Blaberidae) using seventeen species, were estimated based on the DNA sequences of the mitochondrial cytochrome oxidase subunit II (COII) gene. A cladogram inferred using the neighbour‐joining method indicated that Polyphagidae and Cryptocercidae are closely related to each other, and that these two groups are a sister group to the remaining cockroach families. The monophyly of this clade, however, was not strongly supported in terms of bootstrap percentages. Blaberidae and Blattellidae were shown to be sister groups as previously proposed, with Blattidae as a sister group to that clade. Non‐weighted and weighted parsimony analyses were also performed following analyses of nucleotide substitution patterns that indicated saturation of the COII gene among these taxa had occurred. These parsimonious cladograms suggested that Polyphagidae was the basal family, and Polyphaginae, including Cryptocercus as proposed by Grandcolas 1994a ), was not monophyletic. The inferred relationships among cockroach families (Polyphagidae, Cryptocercidae + (Blattidae + (Blattellidae + Blaberidae))) is partly in agreement with some previously published analyses. Additionally, based on molecular data, Asian and American Cryptocercus are suggested to have diverged from one another before the Oligocene (～20 mya).     

Phylogeny of thrips (Insecta: Thysanoptera) based on five molecular loci

The order Thysanoptera (Paraneoptera), commonly known as thrips, displays a wide range of behaviours, and includes several pest species. The classification and suggested relationships among these insects remain morphologically based, and have never been evaluated formally with a comprehensive molecular phylogenetic analysis. We tested the monophyly of the suborders, included families and the recognized subfamilies, and investigated their relationships. Phylogenies were reconstructed based upon 5299 bp from five genetic loci: 18S ribosomal DNA, 28S ribosomal DNA, Histone 3, Tubulin‐alpha I and cytochrome oxidase c subunit I. Ninety‐nine thrips species from seven of the nine families, all six subfamilies and 70 genera were sequenced. Maximum parsimony, maximum likelihood and Bayesian analyses all strongly support a monophyletic Tubulifera and Terebrantia. The families Phlaeothripidae, Aeolothripidae, Melanthripidae and Thripidae are recovered as monophyletic. The relationship of Aeolothripidae and Merothripidae to the rest of Terebrantia is equivocal. Molecular data support previous suggestions that Aeolothripidae or Merothripidae could be a sister to the rest of Terebrantia. Four of the six subfamilies are recovered as monophyletic. The two largest subfamilies, Phlaeothripinae and Thripinae, are paraphyletic and require further study to understand their internal relationships.     

Gene rearrangement and sequence analysis of mitogenomes suggest polyphyly of Archaeobalanid and Balanid barnacles (Cirripedia: Balanomorpha)

The acorn barnacles (Cirripedia, Thoracica, Balanomorpha) are a diverse group of crustaceans found in virtually all marine and estuarine habitats. Barnacles are important model species in various biological researches, including evolution, intertidal ecology, larval biology and antifouling. However, there remains a lack of a thorough understanding of the phylogeny for this group of animals, particularly at higher taxonomic levels. In this study, we attempt to determine the phylogenetic relationships among balanomorphan families based on analysis of complete mitochondrial genome from various barnacle families and investigate the evolution of mitogenome in barnacles. Whole mitogenomes of six barnacles were newly sequenced, including Acasta sulcata (Archaeobalanidae), Armatobalanus allium (Archaeobalanidae), Chelonibia testudinaria (Chelonibiidae), Octomeris sp. (Chthamalidae), Savignium biporata (Pyrgomatidae) and Tetraclitella divisa (Tetraclitidae), which exhibit five different gene arrangements. Phylogenetic analysis on 15 complete mitochondrial genome sequences from major barnacle families supported Chthamalidae, Pyrgomatidae and Tetraclitidae formed monophyletic units, but suggested polyphyly of both Archaeobalanidae and Balanidae. Chthamalidae was the earliest diverged lineage in Balanomorpha. Chelonibiidae + Tetraclitidae formed the sister taxon to the monophyletic superfamily Balanoidea (Archaeobalanidae + Balanidae + Pyrgomatidae). The members of Archaeobalanidae and Balanidae intermingled in the inferred topology with the monophyletic Pyrgomatidae deeply nested within. Two Megabalanus species from the family Balanidae and A. sulcata from the family Archaeobalanidae share the same six‐gene‐cluster inversion as compared to the other ten balanomorphan barnacles, providing further evidence for the non‐monophyly for the two families. We showed here that the informativeness of the complete mitogenome sequence and rare genomic events in resolving various questions concerning Balanomorpha relationships. The non‐monophyletic status of Archaeobalanidae and Balanidae falsified many previous hypotheses concerning the complex evolution of Balanomorpha and call for further investigations and careful revision on the taxonomy of the group. Future study focusing on the enigmatic and tentatively basal lineages, for example, Chionelasmatoidea Pachylasmatoidea and Catophragmidae, would be most helpful in fully resolving the phylogeny and mitogenome evolutionary history of acorn barnacles.     

Evidence of a secondary interspecific mitochondrial DNA introgression in the pond loach Misgurnus dabryanus (Teleostei: Cobitidae) population introduced in Japan

The pond loach Misgurnus dabryanus is a freshwater fish with a distribution range spanning the eastern part of the Asian continent, the Korean Peninsula, and Taiwan. The pond loach was transplanted to the Japanese archipelago through the co-inclusion with dojo loach (Misgurnus anguillicaudatus species complex) populations, which were imported live from China for food materials, and it is currently distributed widely across Japan. A previous mitochondrial DNA (mtDNA) analysis revealed that a pond loach population in Ehime Prefecture (Shikoku Island, Japan) included two highly diverged mtDNA groups (Groups I and II). To examine the origin of these two distinct forms of mtDNA within the Japanese pond loach population, we performed phylogenetic analyses using sequences based on the mtDNA of cytochrome oxidase b (cyt b) and the nuclear DNA recombination activating gene 1 (RAG-1). We also conducted a random amplified polymorphic DNA (RAPD) analysis to examine the establishment of reproductive isolation between sympatric pond loaches with two different mtDNA groups. Our mtDNA phylogenetic results indicated that the two diverged pond loach mtDNA sequences showed polyphyletic relationships among Misgurnus species and its related genus Cobitis. In contrast, there were no clear divergence in nuclear DNA among the pond loaches irrespective of their mtDNA groups, and they all formed monomorphic clades in the phylogenetic relationships among the species. The discrepancy between the mtDNA and nuclear DNA genes support that the existence of two diverged forms of DNA within the pond loach population could be attributed to past mtDNA introgressions from other species rather than convergent evolution. Previous mtDNA phylogenetic studies among Cobitidae revealed that the dojo loach also consisted of two genetically diverged polyphyletic clades: an original Misgurnus mtDNA and an introgressed mtDNA from Cobitis species. In our mtDNA result, the Group II haplotype of the pond loach was included in the mtDNA from the introgressed dojo loach. This suggested that the Group II haplotype was derived from introgressed dojo loach mtDNA. The close relationships between the introgressed dojo loach and the pond loach mtDNA indicated that this secondary introgression had recently occurred via hybridization in a recent artificial aquaculture or transportation process. Common RAG-1 alleles and RAPD bands were shared between the sympatric pond loaches with original and introgressed mtDNAs. This indicates that the introgressed mtDNA haplotype is included as one of the polymorphic genotypes within the pond loach populations, and does not represent existence of different cryptic species.     

The phylogeny of stiletto flies (Diptera: Therevidae)

The therevoid clade represents a group of four families (Apsilocephalidae, Evocoidae, Scenopinidae and Therevidae) of lower brachyceran Diptera in the superfamily Asiloidea. The largest of these families is that of the stiletto flies (Therevidae). A large‐scale (i.e. supermatrix) phylogeny of Therevidae is presented based on DNA sequence data from seven genetic loci (16S, 18S and 28S ribosomal DNA and four protein‐encoding genes: elongation factor 1‐alpha, triose phosphate isomerase, short‐wavelength rhodopsin and the CPSase region of carbamoyl‐phosphate synthase‐aspartate transcarbamoylase‐dihydroorotase). Results are presented from Bayesian phylogenetic analyses of approximately 8.7 kb of sequence data for 204 taxa representing all subfamilies and genus groups of Therevidae. Our results strongly support the sister‐group relationship between Therevidae and Scenopinidae, with Apsilocephalidae as sister to Evocoidae. Previous estimates of stiletto fly phylogeny based on morphology or DNA sequence data, or supertree analysis, have failed to find significant support for relationships among subfamilies. We report for the first time strong support for the placement of the subfamily Phycinae as sister to the remaining Therevidae, originating during the Mid Cretaceous. As in previous studies, the sister‐group relationship between the species‐rich subfamilies Agapophytinae and Therevinae is strongly supported. Agapophytinae are recovered as monophyletic, inclusive of the Taenogera group. Therevinae comprise the bulk of the species richness in the family and appear to be a relatively recent and rapid radiation originating in the southern hemisphere (Australia + Antarctica + South America) during the Late Cretaceous. Genus groups are defined for all subfamilies based on these results.     

Phylogenetic relationships in the skin-inhabiting Sarcoptoidea (Acari: Astigmata)

A phylogenetic analysis of relationships is carried out among the skin-inhabiting mites presently included in the families Rhyncoptidae, Audycoptidae and Sarcoptidae. The analysis included eight taxa (five genera of follicle associates and three subfamilies of skin-burrowing sarcoptids) and 41 characters, and generated a single most parsimonious tree of length 60 with a consistency index of 0.745. The genus Caenolestocoptes (Sarcoptidae, Caenolestocoptinae) is the sister group of the assemblage of Ursicoptes, Saimirioptes, Audycoptes (all Audycoptidae) and Rhyncoptes (Rhyncoptidae). Within the latter grouping Audycoptes is the sister group of Rhyncoptes. Based on these results the Caenolestocoptinae Fain & Lukoschus, 1976 and Audycoptidae Lavoipierre, 1964 are synonymised with the Rhyncoptidae Lawrence, 1956. The Rhyncoptidae (sensu nov.) appears to be the sister group of the Sarcoptidae (sensu stricto).The distribution pattern of follicle inhabitation and skin-burrowing in the Sarcoptoidea can be explained by one adaptation to follicle inhabitation (Rhyncoptidae), another to skin-burrowing (Sarcoptidae) and possibly a third in their common ancestor from living on the hairs or on the skin to living in the skin (follicles, burrows or both).New host and locality data for various taxa in the Rhyncoptidae (sensu nov.) are provided. The larva of Audycoptes lawrencei Lavoipierre, 1964, is described and the female redescribed.