Oxynoemacheilus kottelati: A new species of Stone Loach from the Aegean drainage of Anatolia.

Stone Loaches of the genus Oxynoemacheilus are found across the Eastern Mediterranean, the southern Caucasus, Anatolia, Mesopotamia, and Central Iran. To date, 67 species have been assigned to the genus, of which are found in Turkish inland waters, and 36 entirely endemic to the country. Sixteen species are found within the Tigris and Euphrates basins, 14 within rivers and streams draining into the Mediterranean, six in rivers and streams draining into the Black Sea, four in rivers and streams draining into the Caspian, two species within the Konya Basin, two within the Marmara Basin, and one within the Van Basin. 

In a paper published in the journal Zoosystematics and Evolution on 9 May 2024, Davut Turan of the Faculty of Fisheries at Recep Tayyip Erdoğan University, Sadi̇ Aksu of the Vocational School of Health Services at Eskişehir Osmangazi University, Sali̇m Serkan Güçlü of the Faculty of Eğirdir Fisheries at Isparta University of Applied Sciences, and Gökhan Kalaycı, also of the Faculty of Fisheries at Recep Tayyip Erdoğan University, describe a new species of Oxynoemacheilus from streams in the Aegean drainage of Anatolia.

The new species is named Oxynoemacheilus kottelati, in honour of the Swiss ichthyologist Maurice Kottelat, for his contributions to our understanding of the world's Fish fauna. The species is described from a series of Fish collected from the Havran and Karınca streams in Balıkesir Province, Turkey, in October 2023.

Oxynoemacheilus kottelati FFR 15655, (a), (b) Holotype, male, 47 mm; FFR 15656; (c) Paratype, female, 49 mm; Türkiye, Balıkesir Province, Havran Stream. Turan et al. (2024).

Specimens of Oxynoemacheilus kottelati range from 35 to 54 mm in length, with a deep body, laterally compressed at the base of the tail. They have a marbled brownish pattern on their flanks and dorsal surface, but are white on the underside. 

Oxynoemacheilus kottelati, FFR 15657, paratypes: (a) male, 47 mm; (b)female, 46 mm; (c) male, 45 mm; Havran Stream; FFR 15656; (d) female, 48 mm; Karınca Stream; Türkiye, Balıkesir Province. Turan et al. (2024).

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Fishing observed in a Red Fox for the first time.

Red Foxes, Vulpes vulpes, are small mesocarnivorous  found across Eurasia and North America, and introduced to Australia. They are extremely flexible hunters, able to adapt their behaviour to a wide range of prey species. Fish remains have occasionally been found associated with Foxes, but they have never been observed fishing, despite living in close proximity to Humans in many parts of the world, which has led to speculation that they are scavenging Fish rather than actively hunting them.

In a paper published in the journal Ecology on 18 August 2022, Jorge Tobajas of the Departamento de Botánica, Ecología y Fisiología Vegetal at the Universidad de Córdoba, the Instituto de Investigación en Recursos Cinegéticos, and the Biodiversity Research Institute at the University of Oviedo, and Francisco Díaz-Ruiz of the Biogeography, Diversity, and Conservation Research Team at the Universidad de Málaga, describe witnessing a male Red Fox hunting Fish.

The observation was made while Tobajas and Díaz-Ruiz were carrying out fieldwork near the Valuengo reservoir in southern Extremadura, on 24 March 2016. Here, a male Red Fox was observed capturing European Carp, Cyprinus carpio, while they were mating close to the water's edge.

Male Red Fox, Vulpes vulpes, capturing a European Carp, Cyprinus carpio, at the Valuengo reservoir in southern Extremadura, in March 2016. Tobajas & Díaz-Ruiz (2022).

The Fox was observed catching Carp between 1.18 and 2.51 pm, at which point it noticed it was being observed and fled. During this time it made 12 hunting attempts, capturing 10 Fish with an estimated average mass of about 1 kg. This represents a capture success rate of 83%. The Fox was hunting while the Carp were in a reproductive frenzy, and paying little head to the danger present. Fish were captured by simply jumping into the water and grabbing them. After each successful hunt the Fish was carried to a site 20-30 m from the water's edge and buried, hidden, or simply left, presumably for later consumption. The Fox was never observed to eat any substantial part of the Fish, although small parts (possibly eggs?) were consumed on several occasions. At one point a female Fox was observed removing one of the Carp that the male had captured. The male Fox did not challenge this behaviour, suggesting that she was his mate, and that the male was capturing the Fish for the benefit of the female and a litter of pups (unobserved).

Female Red Fox recovering a Fish previously hunted by the male. Tobajas & Díaz-Ruiz (2022).

This observation adds significantly to our understanding of the ecology of the Red Fox, a familiar species generally thought to be well understood, and about which new discoveries would not be expected. It clearly demonstrates that Foxes are highly able hunters of Fish; such a high success rate is unlikely to represent an opportunistic action by a single animal, but is more likely to represent hunting by a Fox with an instinct for such behaviour, which has been further honed through experience.

(a), (b) Two sequences showing the Red Fox, Vulpes vulpes, hunting European Carp, Cyprinus carpio, on the shore of the Valuengo reservoir (southern Extremadura; Spain) during the Carp spawning period, March 2016. (c) European Carp spawning eggs and distracted by the frenzy of reproduction in the shallow reservoir shore. (d) Red Fox carrying a large European Carp far to the shore.(e) European Carp hunted by the Red Fox with the fatal incisions on the head. Tobajas & Díaz-Ruiz (2022).

At first site this observation appeared to represent an incident of 'overkill' by the Fox, i.e. a case of a Fox being presented with an overabundance of easy prey and killing more than it needs to consume out of some sort of misfiring instinct (an explanation often used to justify the hunting of Foxes). However, an animal killing prey which are then consumed by other members of its social unit (such as, in this case, its mate and presumed young) is far from maladaptive. Instead, this appears to be a good use of a seasonally available food resource which coincides with the Fox's own breeding cycle. Similar behaviour has been observed among Arctic Foxes, Vulpes lagopus, which cache large numbers of Bird's eggs in order to feed their young.

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Homatula guanheensis: A new species of Stone Loach from Henan Province, China

The Stone Loach genus Homatula includes a number of small, benthic Fish, which live in the drainage basins of the Yellow, Yangtze, Pearl, Lancang, Nujiang and Red rivers. They are sometimes considered to be a part of the genus Paracobitis, which is morphologically similar, but the two are generally considered separate, due to their different distributions, with Homatula known only from China, and Paracobitis found only in western Asia. Studies based on the morphology of Homatula have suggested that there is more diversity that the current number of species (19-20), but to what extent this reflects variation within species rather than the presence of undescribed species remained unclear, until scientists began to apply genetic identifications to the genus.

In a paper published in the Biodiversity Data Journal on 16 June 2021, Chuanjiang Zhou, Wenwen Ma, Xi Wang, Yongtao Tang, Xiaoling Meng, and Guoxing Nie of the Engineering Technology Research Center of Henan Province for Aquatic Animal Cultivation at Henan Normal University, describe a new species of Homatula from the Guanhe River, in the HanJiang River drainage (a tributary of the Yangtze River),  in Xixia County, Henan Province.

The new species is named Homatula guanheensis, where 'guanheensis' means 'coming from Guanhe', in reference to the Guanhe River where it was found living in cave environments. Like other Stone Loaches, the new species is an elongate, slender Fish. The known specimens range from 76.9 to 109.26 mm in length, and are cylindrical, and flattened towards the rear. The head is short and flattened, and lacks scales. The snout is short, with nostrils closer to the eye than the tip. The eyes are oval, and located towards the top of the head. The lips are thick, and cover the jaw; there are three pairs of barbels. 

 

Homatula guanheensis (holotype, HNU 010048, 99.6 mm SL). (A) Lateral view; (B) Dorsal view; (C) Ventral view; (D) Mouth characters; (E) Intestine form; (F) X–ray (lateral view). Zhou et al. (2021).

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Misgurnus bipartitus: An invasive Weatherfish found in Austria.

Throughout the world, there is an increasing number of alien species, sometimes with negative effects on indigenous taxa. This is also true for Weatherfish of the family Cobitidae. Eschmeyer’s Catalogue of Fishes lists seven species of Misgurnus and one species of Paramisgurnus, mostly known from East Asia. Misgurnus fossilis is the only Weatherfish native to Europe. It is a species of special national and European conservation concern and mainly threatened by the loss of suitable habitats. Negative impacts on European Weatherfish populations may further arise by the spread of allochthonous Weatherfish due to potential interspecific competition, but also by potential hybridisation. Hybridisation has been documented in natural populations of Paramisgurnus dabryanus and Misgurnus anguillicaudatus. Hence, identifying potentially invasive alien Weatherfish and taking actions against their further spread might be crucial to the long-term survival of the indigenous species.

Weatherfish were initially farmed for the food industry in Asia. Subsequently the aquarium trade of ornamental pond Fish has fueled their global spread and concordantly reports of alien Weatherfish have been ever increasing. Today, populations of Asian Weatherfish are known from Australia, North America, South America and Asia outside of their natural range. From Europe, Misgurnus anguillicaudatus, the Oriental Weatherfish has been reported from Italy, Spain, Germany, and the Netherlands. Furthermore, two studies in the last decade have confirmed Paramisgurnus dabryanus, from Switzerland and Germany, respectively.

In a paper published in the journal BioInvasions Records on 30 March 2020, Lukas Zangl of the Institute of Biology at the University of Graz, and the Studienzentrum Naturkunde at the Universalmuseum Joanneum, Michael Jung of the Eberstaller Zauner Büros, Wolfgang Gessl and Stephan Koblmüller, also of the Institute of Biology at the University of Graz, and Clemens Ratschan, also of the Eberstaller Zauner Büros, report the first record of an alien Misgurnus species in Austria.

Based on morphology, DNA barcodes (part of the mitochondrial cytochrome oxidase subunit 1 gene) and sequences of the nuclear recombination activating gene 1 Zangl et al. have to identified the Fish to the species level and relate it to recent findings of alien Weatherfish species in Germany. Furthermore, they discuss difficulties in the correct species identification of alien Weatherfish species, even when DNA sequence data are available, as systematics and taxonomy, especially of the genera Misgurnus and Paramisgurnus, are still not fully resolved.

On 18 October 2018 two strange Cobitid individuals (both with a total length of 125 mm) were caught in the central area of the impoundment of the Egglfing-Obernberg power plant in Upper Austria, at the River Inn during an electrofishing survey. Specimens from the river Inn were determined morphologically, sampled, fixed in formalin and deposited at the Biologiezentrum Linz. 

 

(A), (B) Pictures of the two Misgurnus bipartitus caught in the Inn impoundment lake close to the German border. (C) Bird’s eye view picture of the impoundment lake at the Egglfing-Obernberg power plant and a map of Central Europe showing the sampling site close to the German border. Zangl et al. (2020).

Based on characters given in the a by Russuiab ichthyologist Ekaterina Vasil'eva (caudal peduncle depth 2.4–2.5 times in caudal peduncle length vs. 1.3–1.8 times in Misgurnus anguillicaudatus, maximum body depth 8.2–8.6 times in standard length vs. less than 7.5 times in Misgurnus anguillicaudatus) Zangl et al.'s specimens from the Inn were identified as Misgurnus bipartitus. Phylogenetic analysis of 612 base pairs of the mitochondrial cytochrome oxidase subunit 1 gene also grouped the alien Austrian Misgurnus with Misgurnus bipartitus. Interestingly, the Austrian Fish and Misgurnus bipartitus share their haplotype with German Fish previously identified as Misgurnus anguillicaudatus (KX865082, KX865083, KX865084) collected 145 km further upstream in an oxbow of the Inn in Germany. Consistent with previous studies, the genus Misgurnus was found to be paraphyletic. Phylogenetic relationships based on 658 base pairs of the nuclear recombination activating gene 1 mirrored the results of the mitochondrial cytochrome oxidase subunit 1 gene data, although node support was generally lower in the nuclear trees. In the recombination activating gene 1 tree, the Austrian Fish grouped with a Misgurnus sp. 2 from Korea and a single Misgurnu mohoity from Russia. All other Misgurnu mohoity from their native range form a distinct clade, sister to that including the Austrian samples, albeit with limited bootstrap support. It is noteworthy though, that no ecombination activating gene 1 sequences of alleged Misgurnus bipartitus were available to be included in Zangl et al.'s analysis. The maximum intraspecific genetic distance, based on uncorrected p-distances of the cytochrome oxidase subunit 1 gene, varied from 0% within Misgurnus bipartitus to 3.6% within Misgurnu mohoity. The minimum interspecific distance was 9% between Misgurnus anguillicaudatus and Misgurnus bipartitus.

 

Maximum Likelihood phylograms based on 612 base pairs of the mitochondrial cytochrome oxidase subunit 1 gene. Node labels indicate bootstrap support values (1000 bootstrap replicates; only values greater than 85 are shown). Samples in bold were obtained and sequenced in this study. Numbers in parentheses represent GenBank accession numbers. Zangl et al. (2020).

Zangl et al. present the first record of an alien Misgurnus species for Austria. Phylogenetic analysis of the mitochondrial cytochrome oxidase subunit 1 gene clearly clustered the two specimens caught in the Inn impoundment with other previously published cytochrome oxidase subunit 1 sequences of Misgurnus bipartitus. This particular clade also contains three sequences of specimens likely misidentified as Misgurnus anguillicaudatus from further upstream the Inn in Germany, which share the exact same haplotype with the Austrian samples and all Misgurnus bipartitus included in our dataset. In theory, ancient hybridisation could explain this finding, as hybridisation is known to occur between Misgurnus species as well as between Misgurnus and Paramisgurnus. On the other hand, the study which genetically identified the German specimens did not include any sequence of Misgurnu mohoity and Misgurnus bipartitus. Unfortunately, the systematic background of the genera Misgurnus and Paramisgurnus is still not fully resolved. Anabel Perdices, Victor Vasil’ev , and Ekaterina Vasil'eva, for example, suggested synonymy of Misgurnus bipartitus and Misgurnu mohoity based on DNA sequence data of the mitochondrial cytochrome b and the nuclear recombination activating gene 1 genes, a view concordant with Ekaterina Vasil'eva morphological study. However, other studies have granted species level to Misgurnus bipartitus as well, based on clear divergence in DNA sequence data of the mitochondrial cytochrome oxidase subunit 1 gene and morphology. Zangl et al. follow these studies and treat Misgurnus bipartitus as a valid and distinct species. Thus, based on our data we strongly argue that the three specimens found in the German stretches of the Inn river and the two specimens found on the Austrian side do belong to Misgurnus bipartitus, the northern Weatherfish and so might several other findings of alien Loaches in Germany determined as Misgurnus anguillicaudatus down to 46 km upstream of the recent finding, be as well. These findings are also corroborated by nuclear recombination activating gene 1 data, which group the Austrian samples not with Misgurnus anguillicaudatus, but with a distinct lineage within M. mohoity (but note, no recombination activating gene 1 data are available for morphologically identified Misgurnu mohoity).

 

Maximum Likelihood phylograms based on 658 base pairs of the nuclear recombination activating gene 1. Node labels indicate bootstrap support values (1000 bootstrap replicates; only values greater than 85 are shown). Samples in bold were obtained and sequenced in this study. Numbers in parentheses represent GenBank accession numbers. Zangl et al. (2020).

The close genetic relationship of German and Austrian alien Misgurnus from the Inn, however, further indicates a downstream range expansion of at least 145 km, which is also supported by several more recent catches of alien Misgurnus along the German stretch of the Inn downstream the site of first record. Thus, alien Misgurnus seem to use the main stem of the Alpine river Inn with low water temperatures and high turbidity at least as a dispersal corridor. Systematic uncertainties as well as scarce available ecological data on these species further complicate the prediction of the invasive potential, prime habitats and possible conflicts with native biota.

Despite the above-mentioned challenges, Zangl et al. agree that DNA barcoding, and even more so eDNA metabarcoding or the application of diagnostic primers for detecting alien species in eDNA samples helps to detect and identify non-native Misgurnus/Paramisgurnus species, which might be a threat to the autochthonous Misgurnus species. Confronted with a new alien species, facing potential interspecific competition and/or genetic dilution through hybridisation, protection and conservation of Misgurnus fossilis should be enforced. Furthermore, appropriate regulations on the trade of ornamental Fish should be considered in order to reduce the risk of unintentional spread of alien species that could become invasive and threaten the native biodiversity.

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Bhavania annandalei: The identity and distribution of a a Hillstream Loach endemic to the Western Ghats of India.

The Hillstream Loach, Bhavania annandalei, was described by Sunda Lal Hora in 1920 from Tenmalai, in what was then Travancore State (current day southern Kerala), and suggested that the species occurs throughout the southern Western Ghats in the Nilgiris, Malabar, and Travancore. Hora diagnosed Bhavania annandalei from its only known congener, Bhavania australis by a combination of characters; the most prominent of which included a broad snout (rather than a pointed one), interrupted lower lip (as opposed to a continuous one), caudal-lobes equal (rather than a longer lower lobe), and presence of a pair of papillae on the lower lip (rather than thier absence). Hora’s description of Bhavania annandalei was however, based on a single adult female specimen collected by Thomas Nelson Annandale from Travancore, Kerala. Though, Hora (1920) seemed to have access to additional juvenile specimens collected by Captain Robert Sewell from the Nilgiris (Cherambadi) and Wayanad (Nellimunda, Mananthavady, and near Vythiri), he did not examine them or provide other details. Subsequently, Hora extended the distribution of the species to Mysore, based on four specimens collected by M.S. Bhimachar from a stream between Kottigehar and Balehonnur (in what was then Mysore State, i.e. the current day Tunga River System in Karnataka). No details of the specimens were provided. 

In his review on ‘Homalopterid fishes from Peninsular India’, Hora synonymized Bhavania annandalei with Bhavania australis, after examining specimens from throughout its distribution range including Kallar/South Travancore (current day Vamanapuram River, Kerala); Pampadumpara/North Travancore (current day Periyar River, Kerala); Sethumadai Hills/Mysore (current day Anamalai hills near Pollachi, Tamil Nadu); and Kottigehar/Mysore (current day Tunga River, Karnataka), and realising that his description of Bhavania annandalei was based mainly on immature specimens. This synonymy was subsequently adopted by Ambet Gopalan Kutty Menon in his review of the Homalopterid Loaches of India, but without examining the type (or fresh topotypes) of Bhavania annandalei, or the topotypes of Bhavania australis. Later workers followed this synonymy and considered Bhavania to be monotypic. ‘Bhavania arunachalensis’, described in 2007 from Naodhing drainage in Arunachal Pradesh, is considered to be a species of doubtful identity and uncertain placement, and is most likely a species of the genus Balitora. 

Given their hill-stream adaptations (widespread paired fins, flattened ventral surfaces with body suckers and rasping mouths on their ventral surface allowing them to firmly grasp rock or gravel surfaces necessary in the mountain torrents), and the fact that the type locality of Bhavania annandalei (Tenmalai) and Bhavania australis (Walayar) are at least 300 km apart and separated by two significant biogeographic barriers - the Palghat Gap and the Shencottah Gap, it is highly unlikely that the two are conspecific.

In a paper published in the journal Threatened Taxa on 26 July 2020, Remya Sundar of the Center for Aquatic Resource Management and Conservation at the Kerala University of Fisheries and Ocean Studies, VK Anoop and Arya Sidharthan of the School of Ocean Science and Technology, also at the Kerala University of Fisheries and Ocean Studies, Neelesh Dahanukar of the Indian Institute of Science Education and Research and the Zoo Outreach Organization, and Rajeev Raghavan, also of the Center for Aquatic Resource Management and Conservation and School of Ocean Science and Technology, and of the Department of Fisheries Resource Management, at the Kerala University of Fisheries and Ocean Studies, present a re-description of Bhavania annandalei, based upon newly collected specimens.

Six specimens of putative topotypic Bhavania annandalei were collected from Palaruvi falls at Tenmala (Kallada River), Kerala, and six specimens of putative topotypic Bhavania australis were collected from near the Kavarakund falls, upstream of Malampuzha Reservoir, Kerala, India. Samples were collected using a hand net/scoop net during early morning hours, fixed in 10% formalin and transferred to 70% ethanol for permanent voucher storage in the museum collections of the Kerala University of Fisheries and Ocean Studies. Gill tissues were obtained from fresh specimens and preserved in absolute ethanol.

 

Collection localities of putative topotyes of Bhavania annandalei and Bhavania australis. Sundar et al. (2020).

Bhavania annandalei is distinguished from its only known congener Bhavania australis by a combination of characters: low density and sparsely distributed tubercles on dorsal surface of head, especially on operculum, (whereas Bhavania australis has a high density of tubercles on dorsal surface of head and operculum); gape of mouth comparatively farther from snout tip, as a result the rostral barbels reaching anterior border of upper lip, (in Bhavania australis the gape of mouth is closer to snout tip, and rostral barbels reaching posterior border of upper lip); rostral flaps between the rostral barbels fleshier than in Bhavania australis; fewer post-dorsal scales (34–36 compared to 38–41); fewer scales above the lateral line (11–12 compated to 14–15); and caudal peduncle stout with its depth to width ratio 1.8–2.3 (Bhavania australis has a laterally compressed caudal peduncle with depth to width ratio 2.8–3.6).

 

Putative topotypes: (a) Bhavania annandalei; (b) Bhavania australis in life (specimens not preserved). Sundar et al. (2020).

The body of Bhavania annandalei is elongate, dorso-ventrally depressed anteriorly, laterally compressed posteriorly; dorsal profile convex, deepest at dorsal-fin origin. Body wider than its depth at dorsal-fin origin, deeper than wide at anus. Head small, rounded, less than one-fourth of standard length; depressed, longer than broad, with minute sparsely distributed indistinct tubercles on dorsal surface of head. Eyes small, dorso-laterally positioned, not visible from underside of head. Snout pointed in lateral view, round in dorsal view. Nostrils positioned dorsally, closer to anterior border of eye than to snout tip, anterior nostril situated inside a skin flap covering the posterior nostrils. Mouth inferior. Lips fleshy. Gape of mouth less than three times maximum head width. Barbels three pairs, two rostral: outer rostral barbels shorter than inner ones; one pair of maxillary barbels, situated slightly anterior to the angle of mouth. Three fleshy rostral flaps interspaced between rostral barbels. Gill opening small, restricted above the base of the pectoral fin.

 

Dorsal, lateral, and ventral images of putative topotypes: (a) Bhavania annandalei; (b) Bhavania australis. Sundar et al. (2020).

Body with scales except chest and belly. Lateral line complete, with 68–72 small scales. Caudal peduncle slender, its length almost three times its depth. Dorsalfin originating slightly behind the pelvic-fin origin, closer to tip of snout than to caudal-fin base; with two unbranched, followed by seven branched and a simple ray. Pectoral fin elongated, longer than head, with six unbranched, followed by 10 branched and a simple ray. Pelvic-fin length almost equal to head length; fin origin closer to snout tip than to end of caudal peduncle, its posterior end not reaching anus, with two unbranched and eight branched rays. Anal fin with two unbranched and five branched rays. Caudal fin forked, with 19 principal rays. 

Dorsal and ventral view of head: (a), (c) Bhavania annandalei; (b), (d) Bhavania australis. Sundar et al. (2020).

In life Bhavania annandalei is body is chestnut brown on dorsal and lateral sides, creamish-white on chest and belly; 3–4 prominent broad dark brown ventral bands; two broad ventral bands on the dorsalfin base. There are three black-coloured bands on the dorsal fin, 6–7 bands on the pectoral, three bands on the pelvic, 1–2 bands on the anal, and four bands across the caudal fin.

Morphometric analysis is a tool used by palaeontologists, archaeologists, anthropologists and forensic pathologists to analyse and compare specimens. It relies on taking numerous measurements of an object such as a bone or shell, and comparing both these measurements and ratios between measurements to those obtained from other specimens in order to establish relationships between them. 

Morphometric measurements were taken for 37 characters (measured to the nearest 0.1mm using digital calliper) and meristic values were determined for 10 characters using a stereo-zoom microscope. For meristic counts, values in parenthesis after the count respresent its frequency. For statistical analysis of morphometric data, subunits of body were taken as percentage of standard length and subunits of head were taken as percentage of head length. Principal component analysis was performed to check whether the two species formed distinct clusters in multivariate space using correlation matrix. Null hypothesis that the clusters are not significantly different from each other was tested using analysis of similarities employing Euclidian distances and 9999 permutations. Statistical analysis was performed in PAST 4.02.

Using size-adjusted characters, the two species clustered separately on the first two principal component analysis axes. The clusters were significantly different from each other, indicating that the species formed distinct clusters in multivariate space. While lengthlength relationships for most characters showed similar trends for both the species, there were two relationships that showed marked differences. Length-length relationship between caudal peduncle depth and width suggested that width increased rapidly with increasing depth in the case of Bhavania annandalei compared to Bhavania australis. Similarly, length-length relationship between head length and head depth at nape suggested that head depth increased rapidly with increasing head length in the case of Bhavania annandalei compared to Bhavania australis.

Genetic sequences of mitochondrial partial cytochrome oxidase subunit 1 (cox1) of topotypic Bhavania annandalei and Bhavania australis were obtained from the collected specimens. Additional sequences were downloaded from GenBank database. Gene sequences were aligned using MUSCLE and raw genetic distance was estimated using MEGA 7. Data were partitioned into three codon positions of cox1 gene. Partition analysis (a statistical method) and ModelFinder were used to find the right partitioning scheme and nucleotide substitution model for the partition scheme employing minimum Bayesian information criterion. Maximum likelihood analysis was performed in IQ Tree with best partition scheme and ultrafast bootstrap support for 1000 iterations. Phylogenetic tree was edited in FigTree v1.4.2.

Partition analysis and model selection identified separate nucleotide substitution models for all three codon positions, TNe+I for first codon, F81+F for second codon, TN+F+G4 for third codon position of cox1 gene. Maximum likelihood phylogenetic tree based on best partition scheme and model selection recovered Bhavania annandalei and Bhavania australis as a clade sister to Southeast Asian congeners of Balitoridae. Topotypic Bhavania annandalei (MT002520) differed from topotypic Bhavania australis (MT002518) with a raw genetic distance of 6.4% in the cox1 gene.

 

Maximum likelihood phylogenetic tree based on mitochondrial cytochrome oxidase subunit 1 gene using best partition scheme and model selection (lnL of consensus tree = -2631.97). Indoreonectes keralensis (Nemacheilidae) is used as an outgroup. Values along the nodes are percentage bootstraps based on 1,000 iterations. Sundar et al. (2020).

Bhavania annandalei is known with certainty from the Kallada, Vamanapuram, and Neyyar river systems in southern Kerala, India. These river systems drain the western slopes of the Agasthyamalai Hill ranges, south of the Shencottah Gap. It is highly likely that the species also occurs on the eastern slopes of the Agasthyamalai Hills particularly in the Tambaraparini River system in Tamil Nadu, but detailed surveys and voucher specimens are required to confirm this. In this context, Sundar et al. believe that previous records of Bhavania australis from several tributaries of the Tambaraparini, Manimuthar, and Chittar draining the eastern slopes of the Agasthyamalai, could most likely represent Bhavania annandalei.

The density of chromatophores in Bhavania is likely to be dependent on the micro-habitat as well as the colour and type of substratum it inhabits. Other ecological factors that may influence body colour are forest/canopy cover, intensity of light, turbidity, water flow and water temperature. This is reflected in the different body colours shown by the two species in different habitats and locations, an observation which was also made by Sunda Lal Hora. 

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Triplophysa weiheensis: A new species of Tibetan Loach from the Weihe River in Gansu Province, China.

Tibetan Loach of the genus Triplophysa are the most common members of the Stone Loach family, Nemacheilidae, found on the Qinghai-Tibet Plateau. These fish are found in almost all water bodies in the region, with new species of Triplophysa still being reported regularly. As a result, a total of 147 valid species of Triplophysa have been recorded to date, including Triplophysa zhaoi, which is found living in the swamps of the Lükqün Oasis in the Turpan Depression, at an altitude of 50 m below sealevel, making it the lowest living freshwater Fish in Asia, and Triplophysa stolickai which is found in hot springs near the Longmu Lake in western Tibet, at an altitude of 5200 m, making it the highest altitude Fish in Asia, and possibly the highest altitude Fish in the world. 

In a paper published in the journal Zoological Research in July 2020, Chen-Guang Feng of the Key Laboratory of Adaptation and Evolution of Plateau Biota of the Northwest Institute of Plateau Biology of the Chinese Academy of Sciences, and the School of Ecology and Environment at the Northwestern Polytechnical University, Yu Zhang, also of the Key Laboratory of Adaptation and Evolution of Plateau Biota, and of the University of the Chinese Academy of Sciences, Chao Tong, again of the Key Laboratory of Adaptation and Evolution of Plateau Biota, and of the Biology Department at the University of Pennsylvania, Bing-Zheng Zhou and Xiao-Hui Li, again of the Key Laboratory of Adaptation and Evolution of Plateau Biota, and of the University of the Chinese Academy of Sciences, Yong-Tao Tang, again of the Key Laboratory of Adaptation and Evolution of Plateau Biota, and of the College of Fisheries at Henan Normal University, and Wen-Zhu Song and Kai Zhao, once again of the Key Laboratory of Adaptation and Evolution of Plateau Biota, describe a new species of Tibetan Loach from the Weihe River in Gansu Province, China.

Weihe River is a tributary of the Yellow River and originates from the southern part of Gansu Province. Previous studies have reported that southern Gansu is a hotspot area for Triplophysa, with an extensive distribution of species across the river systems. Until now, 17 species of Triplophysa have been reported from the Yellow River system, five of which have been recorded from Weihe River. Following an investigation of Triplophysa species from Weihe River, 15 specimens superficially resembling Triplophysa stoliczkae were collected and are described as a new species based on morphological and molecular analyses.

Map showing sampling sites of Triplophysa weiheensis  (star symbol, solid star for type locality). (1) Zhang River, at Chenjiamo Village, Zhangxian County; (2) Niutou River, at Hongbao Town, Qingshui County; (3) Niutou River, at Maiji District, Tianshui City. Feng et al. (2020).

Previous research has reported that Triplophysa stoliczkae is a striking case of morphological convergence and consists of distinct lineages that are not close relatives. As there has been no formal taxonomic revision for Triplophysa stoliczkae, Feng et al. treated it as a morphological species in this study but considered its different genetic lineages in  phylogeny. These lineages, which were initially mistaken as Triplophysa stoliczkae, exhibit very similar morphology. Thus, they represent a known morphological unit in the genus Triplophysa. Feng et al. specifically measured 61 Triplophysa stoliczkae specimens collected from various water systems and used principal component analysis to visualize morphological differences between Triplophysa stoliczkae and the new species.

The new species is named Triplophysa weiheensis, where 'weiheensis' means from the Weihe River. The body of Triplophysa weiheensis is thick and cylindrical. The dorsal profile of the body is arch-like. Maximum depth of body slightly greater than maximum width, occurring between pectoral and dorsal fins. Caudal peduncle laterally compressed, depth nearly uniform toward caudal-fin base, length longer than head length. Head width greater than depth. Cheeks slightly inflated, V-shaped outline in ventral view. Snout obtuse, sloping downward anterior to anterior nostril. Snout length shorter than postorbital length. Anterior and posterior nostrils close together. Valves around anterior nostrils, but not around posterior. Eyes small, dorsolaterally in head. Interorbital space wide. Mouth inferior. Lips thick and well-developed with furrows; lower lip continuous with shallow median incision. Lower jaw crescentic, uncovered by lower lip. Three pairs of barbels thick, moderately short; inner rostral barbels almost reaching corner of mouth; outer rostral barbels horizontally reaching posterior nostril; maxillary barbels horizontally reaching mid-point of eyes.

Lateral view, dorsal view, and ventral view of Triplophysa weiheensis, NWIPB 1505189, holotype, 65.8 mm. Feng et al. (2020).

Fins short, dorsal fin rounded distally, originating anterior to pelvic-fin origin; dorsal-fin origin near midway between tip of snout and caudal-fin base or slightly nearer to caudal-fin base. Pectoral fin short, not reaching halfway point to pelvic-fin base. Pelvic fin reaching past anus, distal fin tip attaining anal-fin origin when adpressed. Anal fin rounded distally, just posterior to anus. Caudal fin slightly emarginate.

Lateral view of Triplophysa weiheensis, NWIPB 1505189, holotype, 65.8 mm (a) and Triplophysa stoliczkae NWIPB 1707001, 85.1 mm, from the Yellow River system (b). Feng et al. (2020).

Skin scaleless. Lateral line tapering, interrupted on posterior trunk at pelvic-fin distal extremity; few lateral line pores close to caudal-fin base. Stomach U-shaped, expanded. Intestine long, with 6–7 loops, one hidden loop surrounded by 5–6 loops). Bony capsule of air bladder small and thin, closed laterally; posterior chamber of air bladder absent.

Micro computerised tomograph of skeletal system of Triplophysa weiheensis NWIPB 1505183, paratype, 64.1 mm. Feng et al. (2020).

In mature males, unbranched and four outer branched pectoral-fin rays thickened, covered with breeding tubercles on dorsal surface. Small breeding tubercles also present on both sides of head in liber apophyses extending from anterior lower margin of orbit to base of outer rostral barbel. These characters do not occur in females.

Sexual dimorphism of Triplophysa weiheensis. Dimorphic characters are highlighted in red circles. Feng et al. (2020).

Specimens were collected from flowing streams with gravel or sandy substrates at 1360–1768 m above sealevel. River water became muddy at about 0.5 m deep. Periphytic Algae, sand, and Insect larvae (e.g. Chironomids) were found in the stomach of specimens. Other species collected with Triplophysa weiheensis included Triplophysa dalaica, Triplophysa minxianensis, Pseudorasbora parva, Gobio huanghensis.

Habitat of Triplophysa weiheensis. (a) Type locality: Zhang River, at Chenjiamo Village, Zhangxian County; (b) Niutou River, at Hongbao Town, Qingshui County. Kai Zhao in Feng et al. (2020).

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