Growth and development of Japanese large-footed bat, Myotis macrodactylus (Temminck)(Vespertilionidae)

Abstract

This article deals with A) period and sequence of shedding in deciduous dentition, B) abnormal teeth formula in permanent dentition, C) period and sequence of alveolar eruption in the both dentitions and D) description of forms of the deciduous and permanent teeth in Japanese large-feooted bat, Myotis macrodactylus (Temminck). Furthermore these were compared with the other species of bats.The teeth formula with deciduous teeth was 120. 1. 1034. 123 12. 1. 34. 123. 1. 34. 123. 1. 1034. 123All deciduous teeth were complete and fully grown at birth. The shedding of these teeth started at 10 days of age and lasted until 30 days of age. The approximate sequence of the shedding was as follows: dI1; dI2; then either dPM4or dPM4; next dI3; either dPM3 or dPM3; dC1; and finally dI1, dI2and dC1. In formthe deciduous teeth were very similar to each other. On the other hand they were for the most part quite unlike those of the permanent dentition. They were usually slender and had more or less trifurcated and somewhat recurved tips.Of 219 males and 239 females, thirteen bats (2.8%) had abnormal teeth formula. Upper third premolar, lower third premolar, lower first premolar and upper canine were lost inseven, three, one and one individuals respectively. And another bat had all upper premolars missing. Frequencies of abnormal teeth formula were different among some populations. In permanentdentition some cusps of M1, M2, M1, M2and PM1protruded from limbus alveolaris at birth. Moreover, alveolar eruption of M3 and PM4 occured at 4 days of age. The approximate sequence of the eruption was as follows 1) M12) M13) M2 4) M2 5) PM16)M37) PM4 8) PM49) PM1 10) I111) I3 12) M3 13) C114) either I2 or C115) I116) either I2or PM317) PM3. At 21 days of age, the young had a complete set of dentition. These teeth grew until about 30 days of age, whenthey reached the adult size.