We analysed the karyotype of the Eastern barbastelle, Barbastella leucomelas darjelingensis for the first time, based on the preparation from bone marrow cell of a male specimen which is collected from Omogo-Valley, Mt. Ishizuchi, Ehime Prefecture, on 17th June, 1971. The diploid number (2n) was 32 and fundamental number (FN) 50. The autosomes consisted of a series of 10 pairs of metacentric and submetacentric chromosomes graded in size from large to small, and five pairs of small acrocentric chromosomes. As to the sex chromosomes, the X chromosome was medium-sized and submetacentric, and the Y was a small acrocentric chromosome (Figs. 1 and 2). The karyotype of B. leucomelas was identical to that of B. barbastellus from Europe. It is recognized in general that little karyotypic variation is found within a given genus in bats. Our finding confirmed this understanding. With regard to the phylotaxonomic position of Barbastella, Tate (1942) has included this genus in the Pipistrelloid subgroup of the group Pipistrellini judging from the dental and cranial characters, and he has positioned the group Plecotini in the group Myotini. However, a comparison of the karyotype of Barbastella (2n=32, FN=50) with those of the Plecotini (2n=32 or 30, FN=50 or 52), as shown in Table 1, suggested that it is extremely similar to those of Plecotus (Plecotus). On the other hand, we believe that the affinity among Barbastella, the Pipistrellini and the Myotini is remote because of the considerable degree of karyotypic diversity among them. For example, in the Pipistrellini the chromosome number of Pipistrellus abramus (Pipistrelloid subgroup) is 2n=26, FN=42 and that of Vespertilio orientalis (Eptesicoid subgroup) is 2n=38, FN= 50; in the Myotini those of some species belonging to the genus Myotis are 2n=44, FN= 50. Taking these data into consideration, it is likely that Barbastella is more closely related to the genera of the Plecotini than it is to the Pipistrelloid genera of the Pipistrellini. Therefore, we support the opinion of Bovey (1949b) in that Barbastella should be excluded from the Pipistrellini and then included in the Plecotini, and agree with the proposal of Williams, Druecker and Black (1970) in that the Plecotini should be separated from the Myotini.
Barbastella leucomelas darjelingensis チチブコウモリの核型が,本報告によつて初めて明らかにされた.すなわち染色体数は2n=32,FN=50,常染色体は大形9対と小形1対のM・SM型グループ,および小形5対のA型からなり,X染色体は中形のSM型,Y染色体は小形のA型であつた.供試したB.leucomelasの核型はヨーロッパ産の別種B.barbastellusのそれと一致した.翼手類においては,一般に同属の種間では核型変異に乏しいという傾向がみられるが,本属においてもその傾向を示唆する結果が得られたことは興味深い.Barbastellaの系統分類学的位置について,Tate(1942)は歯や頭骨などの分類学的諸特徴から本属をPipistrelliniイエコウモリ群のうちのPipistrelloidイエコウモリ亜群の1属とした.しかし,Barbastellaの核型(2n=32,FN=50)がPlecotiniウサギコウモリ群を構成する諸属の核型(2n=32 or 30,FN=50 or 52)と著しい類似性を示し,両者はきわめて近い類縁関係にあることが明らかになつたので,筆者らはBarbastellaをPipistrelliniから除外してPlecotiniに入れるべきであることをここに結論すると共に,PlecotiniはMyotiniから独立されるべきものと考える.