Mesozoic origin and 'out-of-India' radiation of ricefishes (Adrianichthyidae).

The Indian subcontinent has an origin geologically different from Eurasia, but many terrestrial animal and plant species on it have congeneric or sister species in other parts of Asia, especially in the Southeast. This faunal and floral similarity between India and Southeast Asia is explained by either of the two biogeographic scenarios, 'into-India' or 'out-of-India'. Phylogenies based on complete mitochondrial genomes and five nuclear genes were undertaken for ricefishes (Adrianichthyidae) to examine which of these two biogeographic scenarios fits better. We found that Oryzias setnai, the only adrianichthyid distributed in and endemic to the Western Ghats, a mountain range running parallel to the western coast of the Indian subcontinent, is sister to all other adrianichthyids from eastern India and Southeast-East Asia. Divergence time estimates and ancestral area reconstructions reveal that this western Indian species diverged in the late Mesozoic during the northward drift of the Indian subcontinent. These findings indicate that adrianichthyids dispersed eastward 'out-of-India' after the collision of the Indian subcontinent with Eurasia, and subsequently diversified in Southeast-East Asia. A review of geographic distributions of 'out-of-India' taxa reveals that they may have largely fuelled or modified the biodiversity of Eurasia.

Insights on COVID-19 impacts, challenges and opportunities for India's biodiversity research: From complexity to building adaptations.

The COVID-19 pandemic has impacted every sphere of human society. The paradigm shift of focus to COVID-related research and management has significantly affected various scientific domains, including biodiversity conservation. We assessed the perceptions of early-career researchers working for biodiversity conservation across India, to understand the impacts of the ongoing pandemic on their research. We administered an online questionnaire survey to 565 respondents, who identified four key areas that are affected by the pandemic: (1) research, (2) conservation (3) education, and (4) communication and networking. Respondents (89.2%) perceived that their fieldwork, followed by travel for meetings and funding were the most affected due to COVID-19 outbreak and subsequent lockdown. Nonetheless, responses on the impact varied between different professional categories and were disproportionate. Our study highlights that majority of the respondents (80%) advocate for stakeholder-driven policies and management practices as the most effective strategy to promote biodiversity conservation, in the post-COVID-19 world. To this end, as a post-pandemic response, we propose holistic solutions such as optimising research funding and collaborations, and supporting and strengthening them by citizen science and big data analytics. Our findings and recommendations will also serve as a paradigm for post-COVID-19 biodiversity policy, advocacy and implementation of the post 2020 biodiversity action plan that supports eco civilization.

Phylogeny of the hillstream loach genus Mesonoemacheilus reveals widespread diversification through ancient drainage connections in the Western Ghats Biodiversity Hotspot.

Rivers draining the Western Ghats (WG) mountain ranges in peninsular India harbor an exceptionally diverse, unique and evolutionarily distinct assemblage of lower vertebrates with high levels of endemism, attributed to their evolution and potentially long history of isolation during the Late Cretaceous or Early Tertiary. A molecular phylogeny of hillstream loaches of the genus Mesonoemacheilus endemic to the WG revealed the presence of four clades which we designate as 'species groups'. A consensus of various species delimitation methods indicates the likelihood of 'at least' seven more undescribed species within Mesonoemacheilus. Molecular clock analysis dates the basal clade around 38 mya in the Paleogene, and subsequent diversification in the Neogene and Quaternary periods resulting in the current genetic diversity. Biogeographic analysis suggests that vicariance events which separated the rivers on either side of the two geological barriers/gaps, the Palghat and Shencottah, in the Neogene, as well as range contractions and cladogenetic events contributed to the current patterns of diversity and distribution of this genus. Our results also provide preliminary indications on the interconnections and faunal exchange between historical river drainages in the WG region.

Phylogenetic position and relationships of mountain loaches (Teleostei: Balitoridae) of the Western Ghats as revealed by CO1 sequences.

The teleostean family Balitoridae comprises small-sized freshwater fishes adapted to swift-flowing torrential mountain streams in South and South-East Asia. Little is known about their molecular phylogenetics and evolutionary biogeography, and much of the scientific literature that references them is focused on morphological taxonomy. In this paper, we generate CO1 sequences for the endemic balitorid lineages of the Western Ghats (WG) Hotspot in India, particularly for the endemic genera, Bhavania, Ghatsa and Travancoria. Integration of these data into a phylogeny revealed that the endemic WG genera together form a well-supported monophyletic clade that shows, subject to our limited taxon sampling, a sister-group relationship to the Southeast Asian genus Pseudohomaloptera. Three WG endemic species of the genus Balitora, namely B. chipkali, B. jalpalli and B. laticauda, though morphologically distinct, have low genetic divergence and barcode gap, suggestive of recent speciation. Interestingly, a fourth WG endemic, B. mysorensis, formed a clade with two species of Balitora from Eastern-Himalaya and Indo-Burma. We also show that all available CO1 sequences assigned to WG endemic balitorid genera in GenBank are misidentifications, and provide diagnostic characters for the accurate identification of these taxa in the future.

Indoreonectes telanganaensis, a new species of loach (Teleostei: Nemacheilidae) from the Godavari Basin of India.

A new species of hill-stream loach, Indoreonectes telanganaensis, is described from a seasonal tributary of the Godavari River at Maisamma Loddi, within the Kawal Tiger Reserve, Telangana State, India. The new species is distinguished from its congeners by a combination of characters including caudal peduncle as long as deep; eye large, its diameter about one-fifth head length; pectoral fin as long as head; nasal barbel reaching the middle of the eye; dorsal-fin origin on vertical through pelvic-fin origin; and bars on the lateral side of the body well defined and wide. We also provide multivariate morphometric, and DNA analysis based on the mitochondrial cytochrome b gene sequence to support the distinction of the new species.

Aenigmachannidae, a new family of snakehead fishes (Teleostei: Channoidei) from subterranean waters of South India.

Pronounced organism-wide morphological stasis in evolution has resulted in taxa with unusually high numbers of primitive characters. These 'living fossils' hold a prominent role for our understanding of the diversification of the group in question. Here we provide the first detailed osteological analysis of Aenigmachanna gollum based on high-resolution nano-CT scans and one cleared and stained specimen of this recently described snakehead fish from subterranean waters of Kerala in South India. In addition to a number of derived and unique features, Aenigmachanna has several characters that exhibit putatively primitive conditions not encountered in the family Channidae. Our morphological analysis provides evidence for the phylogenetic position of Aenigmachanna as the sister group to Channidae. Molecular analyses further emphasize the uniqueness of Aenigmachanna and indicate that it is a separate lineage of snakeheads, estimated to have split from its sister group at least 34 or 109 million years ago depending on the fossil calibration employed. This may indicate that Aenigmachanna is a Gondwanan lineage, which has survived break-up of the supercontinent, with India separating from Africa at around 120 mya. The surprising morphological disparity of Aenigmachanna from members of the Channidae lead us to erect a new family of snakehead fishes, Aenigmachannidae, sister group to Channidae, to accommodate these unique snakehead fishes.

Channa rara, a new species of snakehead fish from the Western Ghats region of Maharashtra, India (Teleostei: Labyrinthici: Channidae).

Channa rara, new species, is described from the Jagbudi River in Maharashtra, India. It belongs to the Gachua group and differs from all its members by the possession of one or more ocelli in the posterior part of the dorsal fin in adults (vs. ocelli absent or 1, rarely 2-3 ocelli in juveniles only). It is further distinguished from most species of the C. gachua group by having 6-7 dark concentric bands on the pectoral fins. We review recent descriptions of species of the genus Channa and conclude that C. royi is a synonym of Channa harcourtbutleri, that the diagnosis of C. shingon from C. harcourtbutleri is seriously flawed and that C. torsaensis is not sufficiently diagnosed from C. quinquefasciata. The recently described C. amari is a junior synonym of C. brunnea.

The subterranean Aenigmachanna gollum, a new genus and species of snakehead (Teleostei: Channidae) from Kerala, South India.

Aenigmachanna gollum, new genus and species, is described from Kerala, South India. It is the first subterranean species of the family Channidae. It has numerous derived and unique characters, separating it from both the Asian Channa Scopoli and the African Parachanna Teugels Daget. Uniquely among channids, A. gollum has a very slender (maximum body depth only 11.1-11.3% SL), eel-like body (head length 20.8-21.6% SL), large mouth (jaw length 60.4-61.1 % HL), 43-44 anal-fin rays, 83-85 scales in a lateral series, an unusual colour pattern and it lacks pored lateral-line scales on the body and body buoyancy. In addition, it is distinguished by its DNA barcode sequence, which is 15.8-24.2% divergent from other species of the family Channidae. Morphological modifications usually associated with a subterranean life, such as reduction of eyes and enhancement of non-visual senses (taste, smell, mechanosensory systems) are absent in A. gollum. However, it shares with subterranean fishes a slight reduction of its pigmentation in comparison to epigean channids.

Pangio bhujia, a new, peculiar species of miniature subterranean eel loach lacking dorsal and pelvic fins from India (Teleostei: Cobitidae).

A unique, new species of eel loach, Pangio bhujia, is described from Kerala, India. It is the first species of Pangio to be described from subterranean waters. It possesses several unusual characters including absence of both dorsal and pelvic fins, the presence of only 3 pectoral-fin rays, 6 anal-fin rays and a unique count of 38 precaudal + 24 caudal vertebrae.

Dario neela, a new species of badid fish from the Western Ghats of India (Teleostei: Percomorpha: Badidae).

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.

Taxonomy of the zodiac loaches, Mesonoemacheilus triangularis, M. tambaraparniensis and M. periyarensis, endemic to the Western Ghats of India (Teleostei: Nemacheilidae).

The Nemacheilid loaches, Noemacheilus triangularis tambaraparniensis and Nemacheilus periyarensis have been widely considered to be synonyms of the zodiac loach, Mesonoemacheilus triangularis. An integrative taxonomic investigation based on topotypic material, involving molecular analysis of two mitochondrial genes (cytochrome oxidase subunit 1 and cytochrome b), multivariate morphometric analysis based on non-metric multidimensional scaling and non-parametric multivariate analysis of variance suggests that the three species are in fact distinct.