Article

Dario tigris and Dario melanogrammus, two new species of miniature chameleon fishes from northern Myanmar (Teleostei: Badidae)

Authors:
To read the full-text of this research, you can request a copy directly from the authors.

Abstract

Dario tigris, new species, is described from mountain streams south of Mogaung, in the Ayeyarwaddy River basin, Myanmar. It differs from congeneric species by its unique colour pattern, which consists of a series of eight straight vertical bars, the first two of which in males are ash-grey and the subsequent six are orange-red in life, combined with a series of small black spots arranged in three to four rows dorsolaterally on the head and nape. It differs further from its close relative Dario hysginon, with which it may occur syntopically, by fewer dorsal-fin spines (modally 14 vs modally 15), and fewer vertebrae (modally 12+12=24 vs modally 12+13= 25). Dario melanogrammus, new species, is another barred Dario from the Chindwin River basin. It differs from all other species of the genus by its zigzagging dark vertical bars; amongst Myanmar species, it can be further distinguished from D. hysginon and D. tigris by more vertebrae (modally 26 vs 25 in D. hysginon, and 24 in D. tigris).

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... male, 21.7 mm SL), which also had well-developed patches of tiny tubercles on the anteriormost branched pectoral-fin rays (Fig. 6). The absence of barbel tubercles in other males (and females) that we the number of miniature species that have been described from this region in the course of the last three decades (e.g., Kullander & Britz, 2002;Britz, 2003Britz, , 2009Kottelat et al., 2006;Roberts, 2007;Britz & Kottelat, 2008;Britz et al., , 2012Britz et al., , 2021Britz et al., , 2022Ou et al., 2011;Anoop et al., 2019;Parenti et al., 2023). Miniature fishes typically exhibit reductions in the lateral-line system (Myers, 1958;Weitzman & Vari, 1988); the reductions that we have documented in this system for Ph. ...
Article
Full-text available
Physoschistura mango, new species, is described from Shan State, Myanmar. It is distinguished from congeners by having an extremely short and incomplete lateral-line canal on the body, with only 5-6 pores; several reductions in the cephalic lateral-line canal system; and by features of the colour pattern, including a dark black to brown horizontal stripe along body side combined with a bright orange-reddish background colour in mature males. With a maximum recorded length of 23.4 mm SL, it represents one of the smallest members of the family Nemacheilidae.
Article
Badis limaakumi, a new species of Badis from Nagaland, Northeast India is distinguished from all its congeners by the following combination of characters: a large (>60 mm SL) and slender body (23.2–28.0% of SL), presence of an opercular blotch at the base of the opercular spine, absence of blotches on the sides and fins, as well as on the cleithrum, and greater number of lateral-line scales.
Article
Full-text available
Dario neela, is described from a small tributary stream of the Kabini River in northern Kerala, India. It can be distinguished from congeners by the male colouration in life, which shows wide rims of iridescent blue in all median fins and the pelvic fin. It is further distinguished from all species of Dario, except D. urops by the number of abdominal vertebrae (14 vs. 11-13), and from all Dario species except D. urops and D. huli by the presence of a conspicuous black blotch on the caudal-fin base. Dario neela is distinguished from D. urops by the absence of the horizontal suborbital stripe and presence of a series of up to eight black bars on the body; and from D. huli by 27-28 vertebrae and 27 scales in a lateral row and the absence of teeth from hypobranchial 3. Dario neela is genetically divergent from both Western Ghats congeners in the mitochondrial CO1 gene, showing an uncorrected p-distance of 5.9% with D. urops and 13.1% to D. huli.
Article
Full-text available
Snakehead fishes of the family Channidae are predatory freshwater teleosts from Africa and Asia comprising 38 valid species. Snakeheads are important food fishes (aquaculture, live food trade) and have been introduced widely with several species becoming highly invasive. A channid barcode library was recently assembled by Serrao and co-workers to better detect and identify potential and established invasive snakehead species outside their native range. Comparing our own recent phylogenetic results of this taxonomically confusing group with those previously reported revealed several inconsistencies that prompted us to expand and improve on previous studies. By generating 343 novel snakehead coxI sequences and combining them with an additional 434 coxI sequences from GenBank we highlight several problems with previous efforts towards the assembly of a snakehead reference barcode library. We found that 16.3% of the channid coxI sequences deposited in GenBank are based on misidentifications. With the inclusion of our own data we were, however, able to solve these cases of perpetuated taxonomic confusion. Different species delimitation approaches we employed (BIN, GMYC, and PTP) were congruent in suggesting a potentially much higher species diversity within snakeheads than currently recognized. In total, 90 BINs were recovered and within a total of 15 currently recognized species multiple BINs were identified. This higher species diversity is mostly due to either the incorporation of undescribed, narrow range, endemics from the Eastern Himalaya biodiversity hotspot or the incorporation of several widespread species characterized by deep genetic splits between geographically well-defined lineages. In the latter case, over-lumping in the past has deflated the actual species numbers. Further integrative approaches are clearly needed for providing a better taxonomic understanding of snakehead diversity, new species descriptions and taxonomic revisions of the group.
Article
Full-text available
Dario urops, new species, is described from a small stream of the Barapole tributary of Valapattanam River in southern Karnataka and from Wayanad District, Kerala. It can be distinguished from its congeners by the presence of a conspicuous black blotch on the caudal peduncle and a horizontal suborbital stripe, by the anterior dorsal fin lappets in males not being produced beyond fin spines, and by its vertebral count.
Article
Full-text available
Phylogenies are increasingly used in all fields of medical and biological research. Moreover, because of the next generation sequencing revolution, datasets used for conducting phylogenetic analyses grow at an unprecedented pace. RAxML (Randomized Axelerated Maximum Likelihood) is a popular program for phylogenetic analyses of large datasets under maximum likelihood. Since the last RAxML paper in 2006, it has been continuously maintained and extended to accommodate the increasingly growing input datasets and to serve the needs of the user community. I present some of the most notable new features and extensions of RAxML, such as, a substantial extension of substitution models and supported data types, the introduction of SSE3, AVX, and AVX2 vector intrinsics, techniques for reducing the memory requirements of the code and a plethora of operations for conducting post-analyses on sets of trees. In addition, an up-to-date, 50 page user manual covering all new RAxML options is available. The code is available under GNU GPL at https://github.com/stamatak/standard-RAxML. Alexandros.Stamatakis@h-its.org.
Article
Full-text available
We reconstructed phylogenetic relationships of the family Badidae using both mitochondrial and nuclear nucleotide sequence data to address badid systematics and to evaluate the role of vicariant speciation on their evolution and current distribution. Phy-logenetic hypotheses were derived from complete cytochrome b (1,140 base pairs) sequences of 33 individuals representing 13 badid species, and using three species of Nandidae as outgroups. Additionally, we sequenced the nuclear RAG1 (1,473 base pairs) and Tmo-4C4 (511 base pairs) genes from each of the badid species and one representative of the outgroup. Our molecular data provide the first phylogenetic hypothesis of badid intrarelationships. Analysis of the mitochondrial and nuclear nucleotide sequence data sets resulted in well-supported trees, indicating a basal split between the genera Dario and Badis, and further supporting the division of the genus Badis into five species groups as suggested by a previous taxonomic revision of the Badidae. Within the genus Badis, mitochondrial and nuclear phylogenies differed in the relative position of B. kyar. We also used our molecular phylogeny to test a vicariant speciation hypothesis derived from geological evidence of large-scale changes in drainage patterns in the Miocene affecting the Irrawaddy- and Tsangpo-Brahmaputra drainages, in the southeastern Himalaya. Within both genera, Badis and Dario, we observed a divergence into Irrawaddy- and Tsangpo-Brahmaputra clades. Using a cytb substitution rate of 8.2 x 10(-9) (substitutions x base pair(-1) x year(-1), we tentatively date this vicariant event at the Oligocene-Miocene boundary (19-24Myr). It is concordant with a hypothesized paleo connection of the Tsangpo river with the Irrawaddy drainage that was most likely interrupted during Miocene orogenic events through tectonic uplifts in eastern Tibet. Our data, therefore, indicate a substantial role of vicariant-based speciation shaping the current distribution patterns of badids.
Article
Full-text available
Two hundred and seven species of fish, mostly Australian marine fish, were sequenced (barcoded) for a 655 bp region of the mitochondrial cytochrome oxidase subunit I gene (cox1). Most species were represented by multiple specimens, and 754 sequences were generated. The GC content of the 143 species of teleosts was higher than the 61 species of sharks and rays (47.1% versus 42.2%), largely due to a higher GC content of codon position 3 in the former (41.1% versus 29.9%). Rays had higher GC than sharks (44.7% versus 41.0%), again largely due to higher GC in the 3rd codon position in the former (36.3% versus 26.8%). Average within-species, genus, family, order and class Kimura two parameter (K2P) distances were 0.39%, 9.93%, 15.46%, 22.18% and 23.27%, respectively. All species could be differentiated by their cox1 sequence, although single individuals of each of two species had haplotypes characteristic of a congener. Although DNA barcoding aims to develop species identification systems, some phylogenetic signal was apparent in the data. In the neighbour-joining tree for all 754 sequences, four major clusters were apparent: chimaerids, rays, sharks and teleosts. Species within genera invariably clustered, and generally so did genera within families. Three taxonomic groups-dogfishes of the genus Squalus, flatheads of the family Platycephalidae, and tunas of the genus Thunnus-were examined more closely. The clades revealed after bootstrapping generally corresponded well with expectations. Individuals from operational taxonomic units designated as Squalus species B through F formed individual clades, supporting morphological evidence for each of these being separate species. We conclude that cox1 sequencing, or 'barcoding', can be used to identify fish species.
Article
Five species of Badidae are reported from Bangladesh, with morphological diagnoses and mitochondrial DNA sequences (cytochrome b, cytb; and cytochrome c oxidase subunit I, coi). Dario kajal is recorded from Bangladesh for the first time with a precise locality. Badis badis is reported from several localities in central Bangladesh. Badis chittagongis is redescribed on the basis of samples from the region of Cox′s Bazar, including Maheskhali Island. Badis pallidus, new species, is described from the Sangu and Karnafuli River drainages in Bangladesh. It is most similar to B. chittagongis, but differs slightly in colouration and meristics, and is separated by 3.8% uncorrected p-distance in coi from B. chittagongis. Badis chittagongis and B. pallidus are almost identical in morphology, colour pattern and meristics, but occupy different habitats and are reciprocally allopatric. Pronounced genetic difference but similar morphology in these two species may be due to strong stabilizing selection for cryptic colouration in Badis. Badis rhabdotus is a new species from northeastern Bangladesh and adjacent Meghalaya in India. It is distinguished from congeneric species by the colour pattern, including well-defined narrow vertical bars; posterior bars curved; and meristics. Species delimitation analysis of an alignment comprising all coi sequences available from GenBank longer than 600 bp and attributed to species of Badidae (21 June 2018) plus our coi sequences and outgroup sequences of Nandus nandus, using pairwise p-distance and the computer software GMYC, ABGD, and bPTP, produced similar results. Among 103 coi sequences of Badidae, unidentified or tagged with one of 18 valid species names, uncorrected p-distance suggests 27 OTUs at 2% difference threshold; ABGD found between 15 and 55 OTUs; GMYC with single evolutionary rate 33 OTUs, with multiple evolutionary rates 32 OTUs; PTP, mPTP and bPTP 27–28 OTUs. Phylogenetic analysis based on coi and cytb sequences support previous analyses and previously proposed species groups. Inadequate recent species descriptions and many misidentifications or provisional identifications of published DNA sequences hamper progress in species-level systematics in Badis. Based on published morphological data, Badis triocellus cannot be distinguished from B. singenensis; Badis dibruensis and B. pancharatnaensis cannot be distinguished from B. badis; Badis andrewraoi, B. autumnum, B. kyanos, and B. soraya are insufficiently well distinguished from each other.
Article
Chaudhuria ritvae, new species, from the lower Ayeyarwaddy River Drainage, southern Myanmar, is distinguished from C. caudata by a greater number of caudal vertebrae, shorter jaws, larger and broader ribs, neural arches of vertebrae without fenestration, absence of spots associated with base of dorsaland anal-fin rays, sparse body pigmentation consisting of only minute widely separated melanophores, and absence of pigmentation along pectoral-fin rays. It differs from its only other congener, C. fusipinnis, by having the dorsal and anal fins separate from the caudal fin, by a smaller number of dorsaland anal-fin rays, by a greater number of caudal-fin rays and by the presence of teeth on hypobranchial 3.
Article
Dario huli, new species, is described from a small tributary stream of the Tunga River in southern Karnataka, India. It can be distinguished from all its congeners except D. urops by the presence of a conspicuous black caudal-fin blotch and by anterior dorsal-fin lappets in males not being produced beyond fin spines. It is readily distinguished from Dario urops by the absence of the horizontal suborbital stripe (vs. presence), the presence of a series of up to eight black bars on the body (vs. 2-3 black bars restricted to caudal peduncle), 25 scales in a lateral row (vs. 28), 3-5 tubed lateral-line scales (vs. tubed lateral-line scales completely absent), 13+13=26 vertebrae (vs. 14+14-15=28-29), and the presence of teeth on hypobranchial 3 (vs. absence of teeth).
Article
Dario kajal, new species, is described from Seinphoh stream in the Jaintia Hills of Meghalaya, India. It can be distinguished from all other congeners by the presence of a postorbital stripe that continues behind the eye in line with the preorbital stripe and by the presence in males of a series of double bars restricted to the upper half of the body. The discovery of D. kajal in the Meghna River drainage raises the number of Dario species to five and raises interesting questions about the biogeography of the genus.
535-1538) Naturalis Historia. Aldus, Venetia, 314 + 303 + 195 pp., index
  • G Plinius Secundus Maior
Plinius Secundus Maior, G. (535-1538) Naturalis Historia. Aldus, Venetia, 314 + 303 + 195 pp., index.