Michael Norén

Phylogeny of the Prolecithophora (Platyhelminthes) inferred from 18S rDNA sequences

Complete nuclear 18S rDNA sequences from 14 species of the Prolecithophora were obtained and used, in combination with literature data, to generate the first parsimony‐based hypothesis of the phylogeny of the order Prolecithophora (Platyhelminthes). Bootstrap, parsimony jack‐knife, and Bremer support values were computed and compared. The monophyly of the Prolecithophora sensu stricto and the family Plagiostomidae is strongly supported. The taxa Separata, Combinata, and Plagiostomum are shown to be nonmonophyletic. Cylindrostomidae and Ulianinidae are transferred to Pseudostomidae. The Urastomidae is not part of the Prolecithophora.

Xenoturbella 's molluscan relatives|[tdot]|

Despite detailed morphological studies, the phylogenetic relationships of Xenoturbella bocki Westblad 1949 have remained unclear. The marine, worm-like X. bocki was first described as an acoel flatworm. Later it was proposed to be a deuterostome, and most recently as the sister taxon of the Bilateria. Here we present DNA sequence data that place X. bocki within the protostome clade Eutrochozoa.

Molecular phylogenetic interrelationships of the south Asian cyprinid genera Danio, Devario and Microrasbora (Teleostei, Cyprinidae, Danioninae)

Molecular analysis of mitochondrial cytochrome b sequences from 159 species of the family Cyprinidae supports the subfamily Danioninae, of which Rasborinae is shown to be a junior synonym. Analysis of combined cytochrome b and a fragment of the nuclear rhodopsin gene from 68 species, including 43 species representing the subfamily Danioninae, supports phylogenetic distinctness of Danio and Devario. In the combined molecular analysis Microrasbora rubescens, Chela, Laubuca, Devario, and Inlecypris form a clade with M. gatesi, M. nana and M. kubotai being in sister group position to the rest. The sister group of this Devario clade is Danio. Inlecypris is synonymized with Devario. Microdevario, new genus, is proposed for M. gatesi, M. nana and M. kubotai, supported by morphological characters. In the cytochrome b analysis, M. rubescens falls outside Devario, and there is no morphological support for including M. rubescens in Devario. In the cytochrome b analysis Esomus + Danionella is the sister group of Danio and Devario clades, whereas in individual rhodopsin and combined analyses Esomus is the sister group of Danio, and of Danio and the Devario clade, respectively. Sundadanio presents at least one strong morphological synapomorphy with Danio, but is positioned in molecular trees either as a member of the Cyprininae or as sister group of the remaining Danioninae. In the morphological analysis, small‐sized species grouped together based on shared reductions that are not necessarily synapomorphies. In the molecular analysis, small‐sized species such as Danionella and Sundadanio possess long branches and their position varies, but they did not group together. This suggests morphological homoplasy, but phylogenetic positions are not well supported in the molecular analyses

The phylogenetic position of the Prolecithophora (Rhabditophora, ‘Platyhelminthes’)

Complete 18S ribosomal DNA (rDNA) sequences and partial 28S rDNA sequences from a selection of rhabditophoran taxa were obtained and used in combination with literature data to determine the phylogenetic position of the Prolecithophora and of two families sometimes included in the Prolecithophora, the Urastomidae and the Genostomatidae. The results are largely compatible with earlier molecular studies when supported clades are considered, and adjusting for the denser taxonomic sampling of this study. The position of the Proseriata is not compatible with the taxon Seriata, which is rejected. The Rhabdocoela excluding the Fecampiida and the Neodermata is monophyletic. The phylogenetic position of the Neodermata cannot be determined, but its placement is not compatible with the proposed taxa Revertospermata and Mediofusata Kornakova & Joffe, 1999, which are rejected. The Urastomidae and the Genostomatidae in all analyses group with the Fecampiida, and it is our recommendation that these taxa be included in the Fecampiida. The amended Fecampiida always group separately from the Prolecithophora sensu stricto, the Rhabdocoela, and the Neodermata. Our analyses reveal the existence of a strongly supported clade consisting of Prolecithophora + Tricladida + the amended Fecampiida, and we propose the name Adiaphanida for this clade. Tentatively the sister group of the Prolecithophora is a clade consisting of the Tricladida + amended Fecampiida.

Devario in Bangladesh: Species diversity, sibling species, and introgression within danionin cyprinids (Teleostei: Cyprinidae: Danioninae)

Four species of Devario are recorded from Bangladesh: D. aequipinnatus, D. anomalus, D. coxi, new species, and D. devario. Devario aequipinnatus has a wide distribution in northern India and Bangladesh. Devario coxi, from southeastern Bangladesh near Cox’s Bazar, differs from D. aequipinnatus in mtDNA (COI, p-distance 1.8%), colouration, proportional measurements, and meristics. The minor morphological differences and low frequency of overlapping meristics suggest relatively recent separation of D. coxi from other D. aequipinnatus. Devario anomalus occurs only in southeastern Bangladesh and is here reported from localities in addition to the type locality. It differs from the similar D. xyrops in adjacent Myanmar by slender body shape and by 2.3% p-distance in the COI gene. Specimens of D. anomalus from the Sangu River were found to have the mitochondrial genome of D. aequipinnatus from Bangladesh, but agree with other D. anomalus in the nuclear RAG1 gene. Devario devario has a wide distribution on the Indian Peninsula and border regions; in Bangladesh it is restricted in distribution to the Ganga, Brahmaputra, and Meghna drainages. Reports of D. assamensis and D. malabaricus from Bangladesh are misidentifications. Perilampus ostreographus M’Clelland, 1839, is tentatively synonymized with D. aequipinnatus. Phylogenetic analysis of 14 species of striped devarios based on the COI gene results in a polytomy with four unresolved clades. Devario deruptotalea from the Chindwin basin is the sister group of D. aequipinnatus+D. coxi. Devario devario is the sistergroup of D. xyrops+D. anomalus.

Chalinochromis cyanophleps , a new species of cichlid fish (Teleostei: Cichlidae) from Lake Tanganyika

Chalinochromis cyanophleps is described from nine specimens, the largest 129 mm SL, from Namansi. It differs from other species of Chalinochromis in plain trunk colouration, absence of black stripes on the head, relatively narrow lips, presence of tricuspid jaw teeth, and presence of five rather than four dentary lateralis foramina. The blue iridescent stripe below the eye is shared with other lamprologin cichlids, but is broader and more conspicuous in C. cyanophleps. Chalinochromis cyanophleps occurs at depths between 6 and 45 m in rocky habitats along the Tanzanian coast of Lake Tanganyika, from Mvuna Island south to Kalala Island, a stretch of about 90 km. Field observations were made of specimens up to 18 cm total length. The COI DNA barcode sequence differs by 1.8% from that of C. popelini.

Danio annulosus , a new species of chain Danio from the Shuvolong Falls in Bangladesh (Teleostei: Cyprinidae: Danioninae)

Danio annulosus, new species, is described from a small pool below the Shuvolong Falls in the Kaptai Lake system in Bangladesh. It shares with chain danios (D. assamila, D. dangila, D. catenatus, D. concatenatus, and D. sysphigmatus) a colour pattern consisting of series of dark rings with light interspaces along the side, complete lateral line, 14 circumpeduncular scales, a produced first ray in the pectoral fin, and a black humeral spot. It differs from other chain danios in possessing much shorter pectoral and pelvic fins, and a humeral spot that is slightly wider than deep instead of round or deeper than wide. The mitochondrial cytochrome c oxidase subunit I (COI) sequence separates D. annulosus from the most similar species, D. catenatus by a p-distance of 3.4%. Although recorded from only a single locality, Danio annulosus is expected to have a wider distribution in the Karnafuli River drainage.

Laubuka tenella, a new species of cyprinid fish from southeastern Bangladesh and southwestern Myanmar (Teleostei, Cyprinidae, Danioninae)

Abstract Laubuka tenella is a new species characterized by the colour pattern, consisting of short dark vertical bars anteriorly on the side, and a dark lateral band posteriorly on the side, combined with a relatively short pelvic fin and 29–30 lateral-line scales. It is separated from other Laubuka analysed by minimum 9 % uncorrected p-distance in the mitochondrial COI gene. The type series is composed of specimens from small streams in the Cox’s Bazar District in Bangladesh (the type locality), and the Thandwe River drainage in western Myanmar. Laubuka brahmaputraensis is strongly indicated to be a junior synonym of L. laubuca, the second known species of Laubuka in Bangladesh. Eustira ceylonensis, currently in the synonymy of Devario malabaricus, is a valid species of Laubuka.

The enigmatic Betadevario ramachandrani (Teleostei: Cyprinidae: Danioninae): phylogenetic position resolved by mitogenome analysis, with remarks on the prevalence of chimeric mitogenomes in GenBank

Abstract We present the complete mitochondrial genome and a phylogenetic analysis of the danionine cyprinid Betadevario ramachandrani, endemic to the Western Ghats in India. Bayesian phylogenetic analysis of all available mitochondrial genomes of Danionina show that B. ramachandrani is the most basal member of a clade also containing Devario, Microdevario and Microrasbora, and this clade is the sister group of Danio. Seven of 20 mitochondrial genomes downloaded from GenBank for phylogenetic analysis were found to be chimeric, including five curated reference genomes, and this did affect our phylogenetic analysis. At least three of these erroneous sequences have been used in other studies. There is reason to suspect that there are numerous chimeric mitogenomes in GenBank.

First records of Croaking Gourami, Trichopsis vittata (Cuvier, 1831) (Teleostei: Osphronemidae), from Myanmar and Bangladesh

The Croaking Gourami, Trichopsis vittata (Cuvier, 1831), is native to Southeast Asia and Sundaland, with introductions reported from USA, Philippines and India. The species was found by us in Myanmar (1997 and 2013), and Bangladesh (2014 and 2016). DNA analysis supports the view that T. vittata is a species complex. Specimens from Bangladesh, Myanmar and the European aquarium trade are the same genotype as specimens from Thailand, possibly corresponding to Trichopsis harrisi Fowler, 1934, considered a synonym of T. vittata. Non-native populations are likely due to release from aquarium specimens.