Discovery of a new mammal species (Soricidae: Eulipotyphla) from Narcondam volcanic island, India

Abstract

We discovered a new Crocidura species of shrew (Soricidae: Eulipotyphla) from Narcondam Island, India by using both morphological and molecular approaches. The new species, Crocidura narcondamica sp. nov. is of medium size (head and body lengths) and has a distinct external morphology (darker grey dense fur with a thick, darker tail) and craniodental characters (braincase is rounded and elevated with weak lambdoidal ridges) in comparison to other close congeners. This is the first discovery of a shrew from this volcanic island and increases the total number of Crocidura species catalogued in the Indian checklist of mammals to 12. The newly discovered species shows substantial genetic distances (12.02% to 16.61%) to other Crocidura species known from the Indian mainland, the Andaman and Nicobar Archipelago, Myanmar, and from Sumatra. Both Maximum-Likelihood and Bayesian phylogenetic inferences, based on mitochondrial (cytochrome b) gene sequences showed distinct clustering of all included soricid species and exhibit congruence with the previous evolutionary hypothesis on this mammalian group. The present phylogenetic analyses also furnished the evolutionary placement of the newly discovered species within the genus Crocidura.

Complete mitogenome of the endangered and endemic Nicobar treeshrew (Tupaia nicobarica) and comparison with other Scandentians

“…Considering the skeletal variation, the treeshrew species showed intraspecific variation depending upon their distribution in mainland and island ecosystems 74 . A recent molecular study also elucidates the biogeographic connection of smaller mammals in the AN archipelago with the Indo-Malayan and Sundaic realms 7 . The present mitogenome based phylogeny also manifested the close relationship of T. nicobarica with T. minor , T. tana , T. splendidula , and T. montana (distributed in Thailand, Peninsular and East Malaysia, Brunei Darussalam, Sumatra, and Indonesia) as compared with the widespread species T. belangeri known from South and Southeast Asia.…”

“…The AN archipelago was formed due to collision between the Indian Plate and Eurasian Plate which commenced about 50 million years ago and continues today 6 . Due to the distance of the archipelago from the mainland and different diachronic processes, this group of islands accommodates numerous unique elements of biodiversity 7 . This archipelago is a trenchant biogeographic entity that can be a model for evolutionary studies 8 , 9 .…”

Complete mitochondrial genome of critically endangered Crocidura nicobarica (Soricidae: Eulipotyphla) from the Great Nicobar Island, India

“…This plate tectonic also impelled multiple chances for animal oversea dispersal and biological connections between South and Southeast Asian countries (Kamalakannan et al. 2021 ). Nevertheless, the bathymetric study also evidenced a prominent connection between the AN archipelago to Sundaic Island by the well-developed seamounts and volcanic arc-chain (Rodolfo 1969 ; Tripathi et al.…”

“…A recent study reported that a total of 12 Crocidura species are known from India with a new discovery of Crocidura narcondamica from Andaman and Nicobar (AN) Archipelago (Kamalakannan et al. 2021 ). Among them, five species viz., C. andamanensis (Critically Endangered), C. hispida (Vulnerable), C. jenkinsi (Critically Endangered), C. narcondamica (Not Evaluated), and C. nicobarica (Critically Endangered) are endemic to the AN Archipelago (IUCN 2021 ).…”

“… 2020 ; Kamalakannan et al. 2021 ). The molecular studies were rigorously utilized to elucidate the phylogenetic relationship and lineage diversification of Crocidura species throughout the world (Dubey et al.…”