Myotis fimbriatus ( Peters, 1870 )

Ruedi, Manuel, Csorba, Gábor, Lin, Liang- Kong & Chou, Cheng-Han, 2015, Molecular phylogeny and morphological revision of Myotis bats (Chiroptera: Vespertilionidae) from Taiwan and adjacent China, Zootaxa 3920 (1), pp. 301-342 : 321-322

Myotis fimbriatus ( Peters, 1870)

Synonymy. Vespertilio fimbriatus Peters, 1870 . Type locality Amoy, Fujian, China. Myotis taiwanensis Ärnbäck-Christie-Linde, 1908. Type locality Takao, Anping, Tainan, Taiwan. Myotis hirsutus Howell, 1926 . Type locality Yenpingfu, Fujian, China. Myotis fimbriatus: Tate 1941 . First use of current name combination. Myotis taiwanensis: Lin et al. 2004 . Name combination.

Myotis adversus taiwanensis: Simmons 2005 . Name combination.

Myotis taiwanensis: Cheng et al. 2010 . Name combination.

Myotis taiwanensis: Han et al. 2010 . Name combination.

Myotis taiwanensis: Ruedi et al. 2013 . Name combination.

Taxonomic remarks. Peters (1870) described two new Chinese species of Vespertilio (now Myotis ) living in sympatry in Amoy (now Xiamen, Fujian Province). He named the smaller, rarer species with woolly pelage V. laniger (see below for its description), whereas the larger, more common species was named V. fimbriatus , and was characterized by the “margins of interfemoral and lumbar membranes ciliated”; he also mentioned that the wing membrane extended to the middle of the metatarsus, but closer examination of the type specimen (and all recent material) suggest that it rather connects to the ankle, close to the proximal end of the metatarsus. In addition, Peters (1870) also mentioned that the second upper premolar was situated at the inner side of the third, suggesting that it might be displaced inwards from the toothrow, which is not the case on the type and all other referred material. Based on a new series of specimens collected in the same area in Fujian, Howell (1926) described another two species, a smaller form with wing membranes attaching to the base of toes (= M. sowerbyi ), and a larger one, named M. hirsutus . The latter species is characterized by very hairy feet and membranes, and resembles the European M. capaccinii , as Howell suggested. However, he overlooked Peters’ (1870) description of M. fimbriatus , which was based on bats likely caught in the same cave ( Allen 1938). Direct comparisons of the type material indicate that fimbriatus and hirsutus indeed represent the same species, as suggested by Allen (1938) and both are very similar to the type of taiwanensis ( Ärnbäck-Christie-Linde 1908). External dimensions of these three taxa are also very similar, but the latter taxon has a slightly larger skull and a more globose braincase than the type of fimbriatus or hirsutus , and thus should be retained as a valid subspecies (i.e., M. fimbriatus taiwanensis ) endemic to Taiwan. Specimens referred to M. fimbriatus s.l. from Taiwan and mainland China are genetically very similar or identical ( Fig. 3), and confirm that they belong to the same species.

Contrary to previous suggestions based on phenetic comparisons ( Findley 1972; Corbet & Hill 1992), molecular reconstructions ( Han et al. 2010; Ruedi et al. 2013) indicate that M. fimbriatus is not particularly related to M. capaccinii , nor to M. adversus , but is comprised in Clade X ( Fig. 3). This East Asian clade includes other large-footed, trawling bats such as M. pilosus (a senior synonym of M. ricketti ), M. cf. fimbriatus , M. petax and M. macrodactylus ( Fig. 3). Records of M. fimbriatus from Yunnan ( Zhang et al. 2009; Ruedi et al. 2013) refer to specimens that also fit the general morphological characteristics of fimbriatus , but they are larger (FA 42.9 mm; GLS 16.1 mm; CM3 5.9 mm) and are genetically divergent ( Ruedi et al. 2013). They might represent a distinct species in this group and should best be referred as M. cf. fimbriatus (as in Clade X of figure 3) until more detailed taxonomic comparisons are made.

Distribution. Initially, the distribution of this species was limited to Fujian (type locality of both fimbriatus and hirsutus ), SE China ( Corbet & Hill 1992) and Taiwan (type locality of taiwanensis ), where it is widespread and common ( Allen 1938; Lin et al. 2004; Han et al. 2010). Recent morphological and molecular surveys (under the name taiwanensis ), suggest that it is much more widespread along the eastern coast of China, occurring up to Anhui and central Shandong provinces ( Han et al. 2010). As indicated previously, Yunnan specimens referred to this species ( Zhang et al. 2009 and Ruedi et al. 2013) probably represent a distinct taxon ( M. cf. fimbriatus ).

Measurements. See Table 4.

External morphology. This medium-sized Myotis (FA about 40 mm) is characterized by relatively large, hairy feet reaching more than half tibia length ( Table 4). It has relatively long ears, reaching the nose tip when laid forwards. The tragus is nearly parallel, long and pointed, reaching half conch height. Although its dorsal fur is relatively short, it extends well along the tibia, which is typical for this species. The underside fur is also particularly long, including on the patagium along the humerus, and extends considerably on the uropatagium as well, especially along the tibia. These sparse hairs are long, cottony and reach beyond the margin of the uropatagium near the calcar (“lumbar membranes ciliated” as mentioned by Peters in the original description). The general color is greyish brown above. The ventral hairs have darker, slate-grey base but are much lighter near the tip, forming an almost pure white area near the anal region ( Howell 1926). This gives an overall characteristic bicolored aspect to the pelage of M. fimbriatus , with a relatively sharp demarcation line along the sides of the body (see pictures in Lin et al. 2004; Cheng et al. 2010). Wing membranes are attached to the ankle or the proximal base of the metatarsus. The long calcar is unkeeled and extends to four-fifth of the rear edge of uropatagium. This bat bears external similarities with M. horsfieldii (large feet, long calcar and long ears; similar to other water-loving bats), but the latter is not hairy below the patagium, its pelage is not bicolored and the wing membranes attach to the metatarsus near the outer toe, not close to the ankle as in fimbriatus .

Skull morphology. The skull has an inflated braincase, especially in the taiwanensis subspecies, giving a globose appearance when viewed from above or laterally (Fig. 4b). Upper canines are strong and higher than premolars. The latter are aligned in the toothrow and not particularly crowded, while all are visible in the lateral view (Fig. 4b). The lower canines are weaker, but still higher than the larger premolars. Lower molars are strong, with high cusps and all are myotodont.

Natural history in Taiwan. A colonial species found in underground structures, like caves ( Allen 1938) or tunnels ( Han et al. 2010), where it can form quite numerous breeding colonies (up to 1000 individuals in central Taiwan, Lin et al. 2004). It is apparently linked to bodies of water, where it hunts insects above the water surface, like other trawling bats. It is found in both lowland and mountain habitats. In Taiwan, newborns were recorded from November to June, suggesting an extensive breeding season. Such unusual winter reproduction was observed in artificial tunnels containing pipes transporting hot spring water, which certainly enhanced local ambient temperature to provide suitable conditions for the bats to extend their normal breeding time.