The strict orthology of mitochondrial (mt) coding sequences has promoted their use in phylogenetic analyses at different levels. Here we present the results of a mitogenomic study (i.e., analysis based on the set of protein-coding genes from complete mt genomes) of 60 mammalian species. This number includes 11 new mt genomes. The sampling comprises all but one of the traditional eutherian orders. The previously unrepresented order Dermoptera (flying lemurs) fell within Primates as the sister group of Anthropoidea, making Primates paraphyletic. This relationship was strongly supported. Lipotyphla (''insectivores'') split into three distinct lineages: Erinaceomorpha, Tenrecomorpha, and Soricomorpha. Erinaceomorpha was the basal eutherian lineage. Sirenia (dugong) and Macroscelidea (elephant shrew) fell within the African clade. Pholidota (pangolin) joined the Cetferungulata as the sister group of Carnivora. The analyses identified monophyletic Pinnipedia with Otariidae (sea lions, fur seals) and Odobenidae (walruses) as sister groups to the exclusion of Phocidae (true seals).Dermosimii ͉ Eutheria ͉ Mammalia ͉ phylogeny ͉ primate paraphyly M itogenomic (mtg) phylogenetics has contributed considerably to resolving evolutionary relationships among mammals. However, relatively few genomes have been sequenced for some orders and others are still unrepresented. The first eutherian mtg study (1) included five orders: Rodentia, Primates, Artiodactyla, Cetacea, and Carnivora. This study identified a sister group relationship between Artiodactyla and Cetacea and close affinities between these two orders and Carnivora. Because of the absence of an unequivocal outgroup (OG), the relationships relative to Primates and Rodentia could not be resolved, however. The first mtg rooting of the eutherian tree (2), using a marsupial as OG, reconstructed the relationship OG(Rodentia,(Primates,(Carnivora,(Artiodactyla,Cetacea)))), a topology that has been generally identified in subsequent mtg analyses. These two studies also showed that individual mitochondrial (mt) genes did not obligatorily reconstruct the same topology, underlining the necessity of using the concatenated sequences of different genes for maximizing the reliability of the analyses.Most taxonomic schemes recognize 18 orders of extant eutherians (Table 1). It is likely, however, that this number is an underestimate because most molecular studies, both mtg (3, 4) and mt͞nuclear (5-7), split Lipotyphla into separate lineages. Similarly, if Rodentia is nonmonophyletic (8-11), the number of eutherian orders may be still greater than suggested by only lipotyphlan polyphyly.Five eutherian orders are previously not represented by complete mtDNAs. To further complete the picture of eutherian mtg relationships we have added 11 complete mtDNAs to the eutherian data set, including four of these orders: Pholidota, Dermoptera, Sirenia, and Macroscelidea.The phylogenetic position of Pholidota has been a matter of debate. A sister group relationship between Xenarthra and Pholidota in a...

The identification of larval fish has been an important morphological issue in marine biology due to the dramatic transformations that most species undergo from early larval stages to adulthood. Insufficient morphological diagnostic characters in larval fishes made it easy to misidentify them and a difficult process to key to genus and species level. The experiment aims to find out, by applying DNA barcoding, how consistent the morphological identifications can be among larval fish. Larval fish were mainly collected using plankton nets around mangrove areas in Pendas (Johor), Setiu (Terengganu), Pekan (Pahang) and Matang (Perak) Malaysia between April 2015 and October 2015. A total of 354 samples were morphologically identified, mostly to the family level and a few to the genus level. Larval fish ranged from 1.5 mm to 31 mm of total length, with the most abundant individuals being <3 mm. Among them, a total of 177 individuals were selected for DNA barcoding analyses. Molecular works involved polymerase chain reaction (PCR) and sequencing of mitochondrial Cytochrome c Oxidase I (COI) gene fragment (655 base pairs) methods. DNA barcoding enabled allsamples to be identified down to species level. The overall genetic identities ranged from 91% to 100%. Morphological identification classified the specimens into 19 families and 11 genera while DNA barcoding identified them into 19 families 33 genera and 40 species. A comparison between the two methods showed a mismatched identification of 42.6% where the accuracy percentage for morphological identification was moderate for the family level (67.8%) but was low for genus level identification (30%). The DNA barcoding method also managed to successfully identify 86.4% of the samples up to their species level where morphological method has failed to do so. The most misidentified families in the study were Blenniidae, Sparidae, Apogonidae Ambassidae and Monachantidae while almost all samples from the family Gobiidae and Engraulidae were correctly identified to family level because of their distinct morphology. In conclusion, taxonomic studies of larval fish should continue using combination of both morphology and DNA barcoding methods. Morphological identification should be more conservative i.e., when in doubt, it is better to key only to family and not to the genus and species level. DNA barcoding is a better method for deeper taxonomic levels identification with the existence of robust sequence reference libraries and should be able to validate the accuracy of traditional larval fish identification.

This study examines the population genetic structure of Tor tambroides, an important freshwater fish species in Malaysia, using fifteen polymorphic microsatellite loci and sequencing of 464 base pairs of the mitochondrial cytochrome c oxidase I (COI) gene. A total of 152 mahseer samples were collected from eight populations throughout the Malaysia river system. Microsatellites results found high levels of intrapopulation variations, but mitochondrial COI results found high levels of interpopulations differentiation. The possible reasons for their discrepancies might be the varying influence of genetic drift on each marker or the small sample sizes used in most of the populations. The Kelantan population showed very low levels of genetic variations using both mitochondrial and microsatellite analyses. Phylogenetic analysis of the COI gene found a unique haplotype (ER8∗), possibly representing a cryptic lineage of T. douronensis, from the Endau-Rompin population. Nevertheless, the inclusion of nuclear microsatellite analyses could not fully resolve the genetic identity of haplotype ER8∗ in the present study. Overall, the findings showed a serious need for more comprehensive and larger scale samplings, especially in remote river systems, in combination with molecular analyses using multiple markers, in order to discover more cryptic lineages or undescribed “genetic species” of mahseer.

New Zealand's South Island houses a flock of closely related stream-resident fish taxa (Galaxias vulgaris sensu lato), including a number of species recently described on the basis of subtle morphological differences. The taxonomic status of some members of the species complex remains uncertain. This study examines the degree of reproductive isolation between recently recognized morphotypes from Southland (G. 'southern', flatheads; G. gollumoides, roundheads) which co-occur in Bushy Creek, a tributary of the Mataura R. Although these morphotypes are broadly sympatric in Southland and Stewart Island, Bushy Creek is their only documented zone of contact. Molecular (microsatellite, isozyme and mtDNA markers) and morphological analyses of 139 fish samples across a 500-m transect (seven stations) reveal a cline from predominantly G. Southern' ( N = 85) to predominantly G. gollumoides ( N = 54), corresponding with a gradual increase in stream gradient. Multivariate analyses of genotypic and morphological data independently reveal distinct clusters that are completely congruent with mtDNA type, suggesting an absence of mtDNA introgression. Our data support the separate species status of G. 'southern' and G. gollumoides under both biological and phylogenetic species concepts. We suggest that the speciation of these taxa occurred in allopatry through independent losses of diadromy, with sympatry resulting from secondary contact.

This study examined twenty six microsatellite primers developed from three cyprinid fishes (Cyprinus carpio, Barbus barbus and Barbonymus gonionotus) in two indigenous mahseer, Tor douronensis and T. tambroides. A total of 10 (38%) and 12 (46%) primers were successfully amplified producing four and five polymorphic loci in T. douronensis and T. tambroides, respectively. The number of alleles per locus ranging from 2 to 5 and 2 to 7 in T. douronensis and T. tambroides, respectively. A significant deviation from Hardy-Weinberg equilibrium (HWE) was observed at three loci (Barb37, Barb59 and Barb62) in one or more populations in T. tambroides while two loci (Barb37 and Barb62) were deviated in T. douronensis population of Batang Ai. Bayesian cluster analysis performed with STRUCTURE showed that the most likely K value identified was K = 2 with no evidence of population substructuring, similar to those identified by the UPGMA dendrogram. The low genetic distances among populations were also supported by low interpopulation genetic differences (FST) among pairwise populations in both mahseer. Overall, the identified microsatellite loci exhibit promise for use in fine scale population structure analysis of T. douronensis and T. tambroides natural populations.

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This study examined 396 base pairs of the mitochondrial cytochrome b gene from 110 individuals belonging to the genus Hampala , a group of freshwater cyprinids that inhabit Southeast Asia. The samples were taken from various locations throughout Sarawak, Sabah, and peninsular Malaysia. The nucleotide sequences were subjected to phylogenetic analyses by using the neighbor-joining, maximum parsimony, and maximum likelihood methods. All three methods revealed the reciprocally monophyletic relationship of Hampala macrolepidota to the other Hampala forms, thus strongly supporting its status as a distinct species. Phylogenetic analysis also discovered the existence of two H. bimaculata lineages endemic to Borneo: (1)

The diversity of native oysters in many regions is overshadowed by the global dominance of a few economically important species. Here we describe the Muar Oyster, Crassostrea (Magallana) saidii sp. nov., first reported as an established local fishery renowned for exceptional and distinctive flavour over 160 years ago by British colonial officials in Malaysia, but as yet never formally named or described as a species. This new species has a subtle but clear morphological diagnosis dependent on three-dimensional characters, which has long been recognised by local fishers to differentiate the new species from co-occurring C. (M.) belcheri (G. B. Sowerby II, 1871). The Indo-Pacific clade Magallana Salvi & Mariottini, 2016 in Salvi and Mariottini 2017 is a phylogenetically distinct group that nonetheless cannot be morphologically separated from the broader genus Crassostrea Sacco, 1897. Fossils or species known only from shell specimens, though morphologically distinct species, cannot be classified as Magallana, Talonostrea Li & Qi, 1994, or Crassostrea s.s.; therefore, we revise these groups as sub-genera within Crassostrea. Our analysis of the COI barcoding fragment from previously published sequences of all available Magallana species found that gene is not sufficient to separate several economically important species, and revealed more than 5% of sequences in GenBank represent identification errors. The new species Crassostrea (Magallana) saidii sp. nov., which is genetically, morphologically, and gastronomically distinct, is known from only one population under potential threat from urbanisation. Many more global species of Magallana remain undescribed. The systematics of this group is critical to understand the diversity of global oysters, and to understand the sustainable use of species grown worldwide for centuries as our food.