Specimens from Hainan Island and Yunnan Province of China, belonging to the Hemidactylus garnotii-vietnamensis species complex were compared with each other and with specimens from Hawaii, Vietnam and Taiwan in six scale characters. The specimens from Hainan and Yunnan showed good agreement with each other, but significantly differed from those from the other localities. Future karyological study will reveal the taxonomic status of Hainan and Yunnan populations.

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The incidence and burden of plerocercoids of Spirometra erinacei (Cestoda; Diphyllobothriidae) were examined in 12 Elaphe quadrivirgata (Reptilia; Colubridae) captured in Okayama Prefecture, Japan, in the summer of 1984. Plerocercoids were obtained from all of the snakes examined, and the worm burden ranged from 63 to 486 with an average of 323. This great worm burden in snakes results from “biological concentration” due to their predation on infected frogs. Plerocercoids were observed at many sites in snake tissues, especially in the subcutis, muscle, and serosa. In histological examination, cell reaction against plerocercoids was not very severe in general and infiltration by aletocytes was seldom observed around the parasites in the subcutis. But a marked migration of eosinophilic cells was sometimes observed around the parasites near the stomach wall, and compression and histolysis of muscles were observed in some histological preparations. Therefore, a snake infected with a large number of plerocercoids will be severely damaged as a whole. Since many plerocercoids and damage caused by them were chiefly observed in the muscles, the locomotor ability of snakes will decline to the point that they are readily caught by the final carnivorous hosts. This phenomenon is considered to be one of the strategies of the parasites for survival.

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Cranial anatomy and swallowing behavior of the yellow rat snake, Elaphe obsoleta quadrivittata, were examined. The alternating motions of each side, ipsilateral and contralateral, establish a regularly repeated swallowing cycle advancing the jaws along the swallowing axis until eventually contractions of neck muscles take over to complete swallowing. Six marked points on the skull were followed in lateral view by cineradiography and their displacements and accelerations compared. Alternating head swings carry the cranium through swallowing angles that decrease sharply soon after swallowing begins and well before the widest portion of the prey is reached by the jaw angles. The bunching of internal prey may require this early change in swallowing angle. Features of jaw kinematics such as head swivel, jaw movement, and lateral flaring of mandibular joints, serve to shape and accommodate bulky prey. The ectopterygoid controls actual motion of maxilla, placing it at an oblique angle, to ensure that upon closing its rear teeth are first to engage the prey. The palatomaxillary arch retracts late in close phase. Forces developed during retraction play only a small role in actually moving prey into the mouth. Instead, the swallowing progress is achieved more by the advance of the jaws along the prey.

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Seven female and two male newborn mamushis, Agkistrodon b. blomhoffii, were raised to maturity in two years. They were fed weighed mice and did not hibernate as they were kept in a heated room in winter. The means of their body weights and total lengths increased from 6.0g and 22.1cm to 121.3g and 54.7cm. There were cyclic peaks in body weight and total length specific growth rates, and these specific growth rates were correlated in the female. Formulae Y=854X^3.278 for females and Y=680X^3.224 for males were obtained between total length (X m) and body weight (Y g). The monthly weight of food consumed had a higher correlation to the monthly increment of body weight than to that of total length. Body weight (Y g) was also more correlated to total weight of food consumption (X g) than to total length in both sexes. No significant change was observed in conversion efficiency (increment of body weight/weight of food consumed×100%) due to the age, total length, or body weight in either sex. Mean conversion efficiency of females (22.9%) did not significantly differ from that of males (17.4%). Increments of total length and body weight during two years were correlated with both conversion efficiency and total weight of food consumed, and of these four relations, the increments of body weight and weight of total food consumed showed the highest correlation with each other.

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The snake found on Oshima Is., Danjo Islands, has been treated as Natrix sauteri without sufficient discussion. However, this Danjo Islands snake is different from Amphiesma (formerly Natrix) sauteri in the dorsal scale rows formation, an important character in the genus, and very similar to A. vibakari in this character. Therefore, this snake is described as a new subspecies, Amphiesma vibakari danjoensis. The new subspecies is restricted to Oshima Is., Danjo Islands, Japan and characterized by lower ventral count, higher subcaudal count and higher tail ratio than in the other two subspecies of A. vibakari. Further, it shows unique features not seen in other forms of the A. vibakari group (sensu Malnate, including A. vibakari, A. sauteri and A. popei). The internasorostral contact ratio is about 0.5, far smaller than that of the others. Prefrontals have narrow contact with supraoculars. Postoculars are relatively reduced and usually three among seven supralabials enter the orbit.

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Karyotypes of Hynobius tsuensis from the southern Tsusima Island and H. leechii from Kyongju, southern Korea were examined by the Giemsa stain and C-banding techniques. Both species have the karyotype (2n=56) characterized by the absence of a medium telocentric pair and, in this respect, resemble the forms from geographically remote northeastern Japan (northern populations of H. lichenatus and H. tokyoensis, H. nigrescens, and H. takedai) but differ from more adjacent southwestern forms (H. abei, H. nebulosus and southern population of H. tokyoensis). The two species differ in the shape of a medium pair and C-banding patterns of two large homologous chromosomes. Relationships between karyology and systematics among species of the nebulosus and lichenatus groups are discussed.

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The alteration pattern of dorsal scale rows in the yellow-lipped sea snake Laticauda colubrina was investigated and compared between the sexes. In the female, the number of scale rows once increased in the anterior part of the body and was subsequently reduced three times posteriorly, whereas that in the male showed only two reductions. The addition and one reduction in the female were unique to that sex. The last two reductions were common to both sexes, but appeared more posteriad in the female than in the male.

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[in Japanese]

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[in Japanese]

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