Submyotodon caliginosus ( Tomes, 1859 )

Saikia, Uttam, Chakravarty, Rohit, Csorba, Gabor, Laskar, Mostaque Ahmed & Ruedi, Manuel, 2025, Taxonomic reassessment of bats from the Western Himalayas, India and description of a new species of the Myotis frater complex (Mammalia, Chiroptera, Vespertilionidae), Zootaxa 5644 (1), pp. 1-78 : 57-58

28. Submyotodon caliginosus ( Tomes, 1859)

New material: 1 M, 16.04.2019, Ansuya, Chamoli district , Uttarakhand ( V /M/ERS/637) .

Morphological description of specimen: Externally, this bat resembled other small whiskered Myotis occurring in the Himalayas i.e., My. nipalensis and My. muricola . It had a dense, glossy dark brown fur. Individual hairs on the dorsum had light brown tips with dark roots; the ventral hairs had dark roots and greyish brown tips, resembling more to those of My. muricola . The face was hairy with prominent bristle–like hairs. The small feet had a wing insertion to the base of toe. However, the deep emargination on the posterior margin of the ears which projected forwards as an arched lobe near the base of the ear ( Fig. 15F ) was characteristic of this taxon and conveniently separated this genus from any Myotis species ( Ruedi et al. 2021). The shape of the tragus was also different in being curved forwards and only tapering near the tip, a character more akin to Pipistrellus than Myotis .

In lateral view, the braincase appeared particularly flattened (SKH 4.21 mm) when compared to other Myotinae in the region and corresponded well to other congeners i.e., Su. moupinensis from southern China and Su. latirostris from Taiwan ( Ruedi et al. 2021). Lower molars were nyctalodont as against myotodont state in most other Myotis .

DNA: No biological material was obtained here, but COI and CYTB haplotypes (GB MW054921 and MW054885 , respectively) of specimens from Himachal Pradesh were reported in Ruedi et al. (2021) and confirmed that Submyotodon and Myotis were very divergent, the former being the most basal lineage of Myotinae .

Echolocation call: We recorded broadband echolocation calls (bandwidth=61.41 kHz) of short duration (5.6 ms), ending at 53.6 kHz. The calls had a short QCF component. Echolocation calls appeaedr to be separable from those of My. muricola on the basis of a higher end frequency. However, they may be confused with certain calls of My. longipes . The calls of My. longipes typically ended above 60 kHz but may stretch below 55 kHz where they overlap with the ending frequency of Su. caliginosus ( Chakravarty et al. 2020) .

Locality records and ecological notes: Uttarakhand:Ansuya Devi (2000 m), Mandal (1530 m) and Shokharakh (3065 m) in Chamoli district; Pindar Valley (elevation unknown), Bageshwar District ( Chakravarty et al. 2020; present study). Himachal Pradesh: Chatri (1820 m) in Chamba district; Mount Karol (1950 m) in Solan district; Narkanda (c. 2700 m), Shimla (c. 2200 m) in Shimla district; Sangla (2725 m) in Kinnaur district; Samayala (c. 1500 m) in Kangra district ( Lindsay 1927; Ruedi et al. 2021; present study). The records of My. muricola from Kalatop Khajjiar (2480 m) in Chamba district ( Saikia et al. 2011) also belong to this species. In Uttarakhand, this species was caught over a stream at an oak forest edge in and in a primary broadleaved forest. They were also mist netted over a small stream in sub–Alpine habitat in Shokharakh ( Chakravarty et al. 2020). In Himachal Pradesh, individuals were commonly caught in oak and fir forest in similar elevation areas and apparently distributed across all physiographic zones ( Ruedi et al. 2021).

So far, Su. caliginosus is known from northern Pakistan (Dunga Gali, Khyber Pakhtunkhwa Province; c. 34°3’N; 73°24’E, 2300 m) and along the Himalayas from Kashmir, Himachal Pradesh, Uttarakhand, Nepal, and Sikkim in India ( Benda 2010; Chakravarty et al. 2020; Ruedi et al. 2021).

Taxonomic notes: Tomes (1859) described Vespertilio caliginosus from an unspecified locality in India. Most subsequent workers considered it as a synonym of My. muricola , My. nipalensis or My. siligorensis ( Thomas 1915b; Hill 1983; Bates & Harrison 1997; Simons 2005) leading to its uncertain taxonomic status. Ruedi et al. (2021) clarified the situation by reviewing the morphological and genetic differences between these forms and concluded that each of these taxa represent well defined biological species and confirmed the generic distinction of Submyotodon from Myotis . During current investigations, all vouchers in ZSI Solan labelled as “ My. muricola ” from Himachal Pradesh ( Saikia et al. 2011) were re–identified as Su. caliginosus ( Ruedi et al. 2021) . Consequently, the occurrence of My. muricola in Himachal Pradesh is yet to be confirmed, although in Uttarakhand both species were found to occur in symparty (see above and Chakravarty et al. 2020).

Figures

FIGURE 15. Portraits of A) My. blythii (ZSI–NERC V/M/ERS/405), B) My. longipes (ZSI–NERC V/M/ERS/441), C) My. nipalensis (ZSI–NERC V/M/ERS/445), D) My. muricola (released animal), E) My. sicarius (released animal), F) Su. caliginosus (ZSI–NERC V/M/ERS/417), G) Ny. leisleri (ZSI–NERC V/M/ERS/413), and H) Pl. wardi (ZSI–NERC V/M/ERS/415). Inset: Direct comparison of thumb length between Pl. wardi (ZSIS–NERC V/M/ERS/658, left) and Pl. homochrous (ZSIS–NERC V/M/ERS/654, right).