Miniopterus srinii, Srinivasulu & Srinivasulu, 2023

Srinivasulu, Bhargavi & Srinivasulu, Aditya, 2023, A new species of the Miniopterus australis species complex (Chiroptera: Miniopteridae) from the Western Ghats, India, Zootaxa 5296 (2), pp. 233-249 : 237-244

Miniopterus srinii sp. nov.

Srini’s Bent-winged Bat

Holotype. NHMOU. CHI.08.2017, adult male, collected by Bhargavi Srinivasulu and G. Devender, on 07 May 2017. Specimen preserved in ethanol and deposited in the Natural History Museum , Department of Zoology , Osmania University [Hyderabad, India]. The skull has been extracted and cleaned. External features of the holotype as given in Figure 4 .

Paratype. NHMOU. CHI.09.2017, adult male, other details same as holotype .

Type locality. Subterranean cave in Matre (12.102 N, 75.830 E, alt. 860 m asl), near Makuta, Kodagu district, Karnataka, India; evergreen and semi-evergreen forest types present .

Etymology. The specific epithet is an eponym honouring Prof. Chelmala Srinivasulu (affectionately known as Srini) for his contributions to tetrapod biology and taxonomy, especially to bat taxonomy and conservation in South Asia.

Diagnosis. A small-sized bent-winged bat externally largely similar to Miniopterus pusillus , with forearm length ranging from 38.93 to 41.29 mm. Fur deep golden to dark brown, lighter than M. pusillus . 2P3MT longer than in M. pusillus (32.86 mm vs 28.50 mm respectively). Ears small and triangular, with a parallel-sided tragus extending past the low antitragus, relatively shorter, straighter, and positioned deeper within the ear than in M. pusillus . Skull and mandible relatively longer (average GTL 10.58 mm vs 9.65 mm, and average M 14.70 mm vs 13.49 mm in M. srinii and M. pusillus respectively). Palatal emargination broader and more rounded than that of M. pusillus .

External characters. A small bat (FA: 41.29 mm) ( Fig. 4 ). Fur golden brown throughout. On the dorsal surface the hair is long ( Fig. 4a ); basal 3/4 is golden and the rest is cream-coloured. These golden strands are interspersed with black shorter hair strands. On the venter, hair strands are golden at the tip, dark brown in the middle, and cream at the base. Chin to base of neck covered with fine cream-coloured fur, interspersed with short dark brown fur on the chin and its sides. Hair extends to the base of the uropatagium both dorsally and ventrally. Uropatagium and wing membranes covered with sparse short golden hair. Fur on the head short and tricoloured—golden at the tip, dark brown in the middle, and black at the base. Fur on the head extends faintly to the base of the nostrils. Muzzle light grey to flesh-coloured, and sparsely haired. Dark brown and cream-coloured hairs distributed throughout the upper and lower part of the muzzle. The lower lip and area below the eyes cream in colour.

Ears small (8.80 mm) ( Fig. 4b ), roughly triangular, with a broadly rounded tip. Half the pinna is held folded. The folding is narrower toward the distal portion of the pinna. Ears do not exceed the height of the fur on the head. The inner portion of the ear is cream-coloured, while the ventral and the dorsal surfaces of the ear are blackish grey in colour. The dorsal surface of the ears is covered with long strands of golden hair interspersed with dark brown and black hair. The inner portion of the ears has short dark brown and golden strands of hair distributed throughout. The base of the ear has long black, and dark brown hair. The tragus is 3.30 mm long, well-developed, parallel-sided, and has a slight constriction below the broadly rounded tip. The sides of the tragus show slight flanges which exhibit a long concavity in the whole of the length of the tragus. The tragus is upright and grey in colour throughout ( Fig. 4c ). The ear border ends just below the tip of the tragus. Antitragus is low and less pronounced.

Membranes black throughout. A well-developed calcar is seen, and both wing membranes and the uropatagium are attached to the base of the foot. Wings show a characteristically long second phalanx of the third metacarpal (32.61 mm), the second phalanx of the fourth metacarpal measures up to half the size of that of the third metacarpal. Tail is long (51.33 mm). Feet are small and covered with scant hair.

Penis. Penis is bulbous at the base; the shaft starts upright and curves down to a simple tip. The shaft is flesh-coloured and turns black towards the tip ( Fig. 4d ). Baculum absent, as typical for the genus Miniopterus .

Cranial characters. The skull (GTL: 14.7 mm) is bulbous, tall, and delicate ( Fig. 5 ). Zygoma slender and delicate, thinner proximally than distally. In the midsection, there is a projection on the zygoma. Sagittal crest well-developed, starts from the frontal region and extends to the parietal region. Lambdoid crests well-developed on the lateral areas of the skull but relatively less developed in the parietal region. Rostrum flat; braincase tall and bulbous, extends abruptly from the base of the rostrum. A shallow medial rostral depression is present. Dental formula is i: 2/3, c: 1/1, pm: 2/3, m: 3/3. Palate is concave. The two pairs of upper incisors are simple, and a noticeable gap exists between the canines and the incisors. The canine is tall and slender, the first upper premolar (pm 2) is smaller than the second upper premolar (pm 4); pm 2 and pm 4 are not in contact. pm 4 is half the height of the canine and pm 4 is 75% the size of m 2. pm 2 also has an additional well-developed lingual cusp posterior to the main cusp. pm 4 is in contact with the metastyle of the first upper molar (m 1). The commissure of m 1 consisting of the metacone is slightly narrower than the commissure of the paracone. In m 2, the commissures, metacone, and paracone are well-developed and are similar in size. The hypoconal flange, hypocone, and protocone are well-developed in both m 1 and m 2. In the third upper molar (m 3), only metastyle, metacone, mesostyle, and paracone can be seen. One pair of tricuspidate, followed by two pairs of bicuspidate incisors are seen on the lower jaw. The pair closest to the canine is larger than the other incisors. pm 4 is taller than pm 2 and pm 3 and is 75% the height of the canine. Coronoid process and the articular process of the lower jaw equal in height, angular process well-developed and extends outward.

Morphological comparisons. Externally, Miniopterus srinii is similar to other species in the M. australis species complex, and is largely indistinguishable from M. pusillus . However, its forearm generally measures smaller (FA 38.93–41.29 mm vs 43 mm) than that of M. pusillus from northeast India ( Saikia et al. 2020) and China (Jones 2009), and larger (FA 38.93–41.29 mm vs 36.2–37.8 mm) than that of M. australis from Palawan Islands, Philippines ( Esselstyn et al. 2004). FA in this species, however, overlaps with M. pusillus from different parts of Southeast Asia ( Kitchener and Suyanto 2002). The external measurements of M. pusillus from Kerala ( Raman et al. 2021) fall within the range of the new species. In comparison, M. magnater measures much larger (FA: 50.6 mm) ( Saikia et al. 2020), followed by M. phillipsi from India and Sri Lanka (47.0± 1.5 mm) ( Bates & Harrison 1997; Kusuminda et al. 2022).

The fur colour of M. srinii varies from deep golden to dark brown, while in M. pusillus fur colour varies from light brown to black throughout its distribution range (Bats in China 2009; Kuznetsov et al. 2015). Preserved topotypes of M. pusillus from the Nicobar Islands are much darker in colour than M. srinii (Authors’ pers. obs.). In M. pusillus from Vietnam and China, the fur is very thick throughout the body and continues to be so in the chin area, in contrast, in the case of the new species the chin is sparsely haired. In M. magnater , the fur is brown in colour ( Saikia et al. 2020), and in M. fuliginosus it ranges from greyish black to brown (Authors pers. obs.).

The structure of the palatal emargination is broad, open, and U-shaped in M. srinii , while in M. pusillus from northeast India and from Nicobar Island (ZSI Reg. No. 19130), it is narrower near the incisors and looks more like a broadly rounded V-shaped structure. In M. magnater , it is V-shaped ( Saikia et al. 2020); in M. phillipsi , it is Ushaped (Authors’ pers. obs.). In M. srinii , there is a projection on the middle portion of the zygoma, similar to M. pusillus from northeast India ( Saikia et al. 2020) and from the Nicobar Islands ( Fig. 6 ). However, the zygoma are more robust in M. srinii than in M. pusillus .

Echolocation. Calls of M. srinii are typical narrow band frequency-modulated (FM) calls with a FmaxE of 77.62 ± 7.98 kHz (64.7–97.2 kHz), Fs of 130.00 ± 11.16 kHz (90–154 kHz), Fe of 58.38 ± 1.43 kHz (53–64 kHz), and duration of 4.18 ± 1.16 ms (2.1–8.0 ms) ( Fig. 7 ).

Natural History. This species is found in evergreen, semi-evergreen, and moist deciduous forests of Kerala, Tamil Nadu, and southern Karnataka, India. In southern Karnataka, it was found roosting in sympatry with Myotis peytoni in subterranean caves. In its range, it is found in sympatry with Miniopterus phillipsi .

Figures

FIGURE 4. External features of Miniopterus srinii sp. nov. [A—view of head of a live individual; B—shape of the ear and tragus in preserved condition; C—colour of dorsal fur of a live individual; D—frontal view of the penis of a live individual].

FIGURE 5. Skull and mandible of Miniopterus srinii sp. nov. Scale: 2 mm. [A—dorsal view of skull; B—ventral view of skull; C—lateral view of skull; D—dorsal view of mandible; E—lateral view of mandible].

FIGURE 6. Comparison of skull and mandible (in lateral view) of A—Miniopterus srinii sp. nov. and B—Miniopterus pusillus sensu stricto. Scale: 2 mm.

FIGURE 7. Spectrogram of echolocation calls of Miniopterus srinii sp. nov.