The American mink (Neovison vison) as invasive alien species has spread along the Chikuma River in Nagano Prefecture, central Honshu, Japan, through naturalization of animals escaped from fur farms in the past. To clarify genetic structures of the naturalized populations, we genotyped ten microsatellite loci on 126 wild-caught animals from this region. Consequently, the genetic variations of American minks in Nagano were relatively low, and no correlations between genetic distances and geographical distances were observed. Based on the genotype data, animals examined were divided to four genetically different clusters. The results suggest that the genetic characters of the American mink populations around the Chikuma River were not formed after naturalization, but during or before breeding in fur farms. In addition, the present study indicated their migration between localities which may bring gene flow and promote random mating, resulting in genetic structure change in the future populations.

The ocular Harderian gland (HG) in three Balaenopterid species (common minke whale Balaenoptera acutorostrata, sei whale B. borealis and Bryde's whale B. edeni) was investigated at macroscopic and microscopic levels. The gland encircled the eyeball similar to a belt form on mainly the corneal side, and was more developed in the rostral and ventral aspects of the eyeball. The multiple secretory ducts of the gland opened into conjunctival fornix and palpebral conjunctiva. The gland also possessed a prominent duct system composed of tubuli which were divided into lobes. Histochemically, the secretory cells of the gland were characterized by the presence of both acid and neutral glycosaminoglycans for Alcian blue (pH 2.5), periodic acid-Schiff, and the absence of lipids for Sudan black B. These characteristics indicated that there are differences from those of HG in some terrestrial mammals, and suggested it may be one of the adaptations for protecting eyes from sea water in aquatic environments.

In the present study, we determined nucleotide sequences of three sex-chromosomal genes (SRY, ZFY and ZFX) for nine species of the family Mustelidae distributed around Japan, and constructed molecular phylogenetic trees, compared with previously reported phylogenies which were examined based on maternally and biparentally inherited genes. The tree topologies by combined sequence data (about 1,800 bp) of two genes (SRY and ZFY) on Y chromosome were almost the same as those by maternal and biparental genes: the mustelid species were basically divided into five genus lineages (Mustela group, Martes group, Neovison, Lutra and Meles). The branching order of Neovison vison and Mustela erminea was different between sex-chromosomal DNA trees. The higher substitution ratio of Y-chromosomal DNA (926-1143 bp of ZFY) than X-chromosomal DNA (848– 869 bp of ZFX), revealed by the present study, could be responsible for the topological difference. Meanwhile, in the ZFY final introns of Mustela erminea and Meles anakuma, insertions of carnivore-specific SINEs (CAN-SINEs) were found. This indicates that the two homologous SINEs evolved in the mustelid genome and that they were inserted to the ZFY final introns lineage-independently after species radiation of Mustelidae.

By using cranial measurements, about 670 museum specimens collected from China, Korea and Myanmar (= Burma) were identified as either Apodemus peninsulae, A. latronum, or A. draco by dividing 105 localities into 14 areas. First, a cluster of A. latronum was separated from that of A. peninsulae and A. draco in the scatter diagram of the total length of the upper molars plotted against the length of the incisive foramen in respective areas. Second, a cluster of A. draco was separated from that of A. peninsulae in the scatter diagram of the quotient (“ratio of the skull”) plotted against the distance between the anterior-most point of the incisor and the posterior-most edge of the third upper molar in respective areas, when the quotient was calculated in each skull by the distance between the occipital condyle and the posterior-most point of the third upper molar divided by the distance between the anterior-most point of the incisor and the anterior-most edge of the first upper molar. Respective specimens identified as either A. peninsulae, A. latronum or A. draco by the present method were perfectly accordant with those identified by the size of posterior cusp (t7) on the first upper molar.

This study demonstrated the immunohistochemical localization of cytoskeletal proteins, cytokeratin, desmin, vimentin, α-tubulin and α-smooth muscle actin (α-SMA) in the testes of adult and immature lesser mouse deer (Tragulus javanicus). Desmin was found in the sub-epithelial myoid cells of epididymal ducts. The immunoreactivity for vimentin was shown in the peritubular myoid cells and around the nuclei of the Sertoli cells of which the positions indicated various arrangements. In the Sertoli cells, vimentin filaments between the basement membrane and the nucleus were elongated with the migration of the nucleus toward the upper part. Furthermore, vimentin was detected in the Leydig cells and the sub-epithelial myoid cells of epididymal ducts. Alpha-tubulin was apparently extended to the tip of each Sertoli cell cytoplasm, and α-SMA was found in the peritubular myoid cells and the sub-epithelial myoid cells of epididymal ducts. On the other hand, cytokeratin and desmin were not detected in the Sertoli cells, Leydig cells, spermatogenic cells and peritubular myoid cells. In the mouse deer testes, vimentin filaments of the Sertoli cells may not be involved in the migration of the elongated spermatids and spermiation like as rat Sertoli cells because the supranuclear extension of vimentin was scanty.

Postnatal growth and vocalization development in the lesser horseshoe bat, Rhinolophus cornutus, were investigated in the Kyushu District. Parturition occurred in early June. Forearm length of newborn young averaged 16.5 mm in females and 16.3 mm in males, and their body weight averaged 2.4 g. The newborn young at a few days of age were left alone or in a small loose cluster at night. However, mothers returned to the nursery roost from foraging one or two hrs after sunset and embraced their young until sunset, while mothers embraced them three hrs after sunset at colony-forming stage. From newborn to colony-forming stage, forearm length and body weight of young increased noticeably, whereas from colony forming to flying stage growth rates slightly slowed down, especially the rates being more marked in a large colony than in a small colony. From flapping to flying stage, there were two peaks of mother's embracing behavior at night, while most of the young clustered tightly and formed a large colony. Fundamental frequency of calls in a few-day-old young averaged 19.8 kHz. From newborn to colony-forming stage, the number of harmonics reduced 5–6 to 3–4 in both the oral and nasal calls. At flapping stage, oral calls with two or three syllables, contained two or three harmonics, and their fundamental frequency averaged 32.1 kHz, while nasal calls contained only two harmonics, and their frequency averaged 42.6 kHz. At flying stage, young emitted nasal pure tone CF-FM or FM-CF-FM calls, and the second harmonic became more intense than the first one. The dominant frequency of CF-components from flying to self-supporting stage is negatively correlated with the size of forearm length.