Barbastella pacifica, Kruskop & Kawai & Tiunov, 2019

Kruskop, Sergei V., Kawai, Kuniko & Tiunov, Mikhail P., 2019, Taxonomic status of the barbastelles (Chiroptera: Vespertilionidae: Barbastella) from the Japanese archipelago and Kunashir Island, Zootaxa 4567 (3), pp. 461-476 : 470-471

Barbastella pacifica sp. nov.

urn:lsid:zoobank.org:act:AFD93791-1867-4971-ACDE-64F113BBC7AE

Holotype. BSI 168-07, adult male, carcass in alcohol and skull, captured on July, 2006. Collected by Selezneva T.A., Tiunov M.P.

Type locality. Kunashir (Kunashiri) Island, Filatova (Ruyabetsu) stream, ca. 1 km from the mouth ( Selezneva & Tiunov 2007); N 44.190°, E 146.023°.

Paratypes. Kunashir Island : NSMT M 61925, male, carcass in alcohol and skull; Hokkaido : NSMT M 14816, male, dry skin and skull ; NSMT M 18559, male, skull ; NSMT M 18560, female, dry skin and skull .

Other referred material. 19 specimens from Hokkaido and Honshu ; see list above .

Etymology and common name. The name ‘ pacifica ’ applies to the species restriction for islands in the North- West Pacific. ‘ Japanese barbastelle’ can be suggested as a common name for this species since most part of its range cover Japanese islands Hokkaido and Honshu.

Diagnosis. Middle size bat with typical Barbastella appearance. Large species within the genus (condylo-basal length of skull more than 13.6 mm and forearm length no less than 39 mm), with proportionally high brain case, moderately sloped facial profile and long dark-brown fur.

Description. A large species of barbastelle (CBL 13.65–14.45 mm, CM 4.75–5.01 mm, HB 51–61 mm, FA 39.0–43.0 mm), demonstrating all the typical traits of the genus. Ears are broadly triangular, connected at the frontal point, and relatively long (A 14.1–19.0), without an additional lobe on the outer margin (as opposed to B. barbastellus and B. beijingensis ). The tragus is long (ca. 8.5 mm) and more or less triangular; its posterior margin is slightly concave in the upper third and convex at the widest part of the tragus. Ears and naked facial parts are brown.

The fur is long, thick and soft, with somewhat wavy underfur hairs. Hairs are about 10.0– 10.5 mm in length on the back and about 8.0– 8.5 mm long on the belly (almost as long as in B. caspica , and longer than in B. darjelingensis and in specimens from Vietnam). The underfur is dark brown with a slight mixture of pale grayishbrown hairs; guard hairs are dark brown, with pale terminal parts. In adult animals, lengths of the paler parts vary from ca. 1.8 mm on the sides of the back to ca. 4.5 mm in the middle, and can be nearly absent on the nape and head. The overall appearance is deep brown, shadowed with light brown and definitely less glossy than in B. caspica and B. leucomelas . Belly colouration in general is similar to that of the back. Pale tips appear more grayish and are about 1.5–2.0 mm in length. On the sides and in the groin area, the pale parts represent about half of the hair lengths, forming a grayish-coloured zone. On both the back and belly, the transition from dark to pale parts of the hairs is gradual, without any conspicuous border. As a whole, the tone of the fur colouration and the degree of pale shading are most similar to that of B. barbastellus . In immature animals, the pale tips of hairs are less developed, which results in a darker overall appearance.

In the context of the genus Barbastella , the skull of the new species has a moderately high and rounded braincase ( Fig. 6 ). Its frontal part is slightly higher than the temporal part, but less than in B. barbastellus , B. leucomelas or B. beijingensis , and a shallow depression can usually be seen on the level of the coronal suture. The sagittal ridge is not developed and the occipital ridge is weak. The facial part is wide, with a shallow but prominent depression, somewhat less pronounced than in B. darjelingensis ; in the lateral view, the facial profile slopes almost evenly, and concaves only slightly. The anterorbital foramen is large, rounded and situated over the roots of P4; the suborbital channel is ca. 1.2–1.3 mm. The lacrimal foramen is exposed, turned backward and situated above the level of the anterorbital foramen. On the lower jaw, the coronoid process is vertical and short, as in other barbastelles. The angular process is slightly projected backward beyond the level of the articular process, more than in B. barbastellus , but less than in B. darjelingensis , and its tip is blunter than in the latter species.

Teeth are similar to that of other barbastelles. In the upper teeth, the inner incisor is definitely bicuspidate, with a subequal height of both cusps and sometimes with a minute indentation on the posterior edge, about 2/ 5 in height of the appropriate canine. The outer incisor is small, but with a commonly definite posterior cusp (having a sharp rectangular indentation shape); it is similar or slightly smaller than the inner one in the crown area and one third to half of its height. The upper canine is without additional cusps or indentations, and its base is wide-oval on a crosssection. The upper small premolar is highly reduced; in some individuals, it is absent in one or both sides of the jaw. The first and second upper molars have greatly reduced hypocones and basins opened at the base of the metacone. The lower canine has a moderate secondary cusp, which is higher than the outer incisor. The outer incisor crown is somewhat simplified: the posterior supplementary cusp is usually not developed, and in some individuals, one of three main cusps is also rudimentary.

The baculum, as mentioned above, has a specific feature in the shape of the main shaft, which is proportionally wide with a widened and very blunt distal epiphysis. In comparison to the baculum of B. darjelingensis , it is wider and massive.

Overall, the new species, besides genetic differences, can be separated from all other species by its fur colouration: darker, especially on the belly, than in B. leucomelas and B. caspica , more brown than in B. barbastellus and B. darjelingensis , and, from the latter, it also has longer and less contrasting pale hair tips. It differs from B. leucomelas and B. barbastellus by its larger overall size, and from the latter and B. beijingensis , by its ear shape. It differs from B. darjelingensis by its shorter and blunter angular process of the mandible, and from B. beijingensis by a less inflated braincase. The baculum shape easily distinguishes the new species from B. barbastellus , B. leucomelas , B. caspica and barbastelles from Southeast Asia.

Variation. We did not find any variation in the haplotypes between the northern and southern populations of this species, suggesting that the divergence of these populations is very recent. Morphologically, as shown above, these two samples were also indistinguishable; we only found that animals from the Honshu population more frequently lacked upper small premolars. The difference in bacula size between our specimens and an individual depicted by Yoshiyuki (1989) may be a result of age or individual variability, which requires further study.

Distribution. The newly described species is restricted in distribution to the Japanese and Southern Kuril Islands and widely separated from the nearest populations of congeneric species living on mainland Asia. It occurs on Kunashir Island, and on most parts of Hokkaido (except the south-west), and has a sporadic distribution on Honshu (recorded in the Iwate, Fukushima, Tokyo, Kanagawa, Nagano, Gifu, Shizuoka prefectures) and on Sikoku ( Fukui 2015).

Ecological remarks. The natural history is poorly known ( Fukui 2015). Most probably, this species is forest dwelling, inhabiting temperate mixed and broad-leafed forests. Hibernation sites and day roosts are in caves, artificial underground shelters and rock crevices. The population number and natural density is not known; the status of the whole population, and especially the isolated southern sub-populations, requires further in-depth study.

Figures

FIGURE 6. Skulls of the newly describing Barbastella species: a—Barbastella pacifica sp. nov., holotype BSI 168-07, adult male, Kunashir Island; b—Barbastella pacifica sp. nov., NSMT M-8774, female, Honshu, Saitama; c—B. leucomelas, NMP PB2883, adult male, Egypt, Sinai; d—B. cf. darjelingensis, ZMMU S-186685, adult male, Vietnam, Lao Cai. Scale bar 5 mm.