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Imatake S, Imaizumi N, Ohashi Y, Matsumura H, Urakawa M, Konaka Y, Kida T, Yanagita T, Fujisaki H, Wakitani S, Yasuda M. Reproductive cycle and maturation of Swinhoe's tree lizard (Diploderma swinhonis (Günther, 1864)) in Hyuga City, Miyazaki Prefecture, Japan. J Vet Med Sci 2020; 82:1551-1557. [PMID: 32863285 PMCID: PMC7653320 DOI: 10.1292/jvms.20-0283] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Swinhoe’s tree lizard (Diploderma swinhonis) is an arboreal agamid that
is native to Taiwan. The species has been introduced to some areas of Japan and is
regarded as an invasive alien species. In 2016, a nonnative population of D.
swinhonis was discovered in Hyuga City, Miyazaki Prefecture, Japan, but little
information was available on the ecology of the population at the time. The main purpose
of this study was therefore to investigate the reproductive cycle and maturation of this
population. Field research was conducted from 2017 to 2019, and 764 lizards were
collected. Euthanized lizards were dissected and the reproductive organs were examined to
determine the reproductive period, clutch size, clutch frequency and size at sexual
maturity. Females with oviductal eggs or vitellogenic ovarian follicles were observed from
May to October. Clutch size ranged from 2 to 8, and clutch frequency was more than twice a
year. In males, spermiogenesis started in early May and testicular regression was observed
in September. Males with spermatozoa in the epididymides were found from May to November.
Minimum snout-vent length at sexual maturity was 50.2 mm in females and 53.0 mm in males.
Comparisons of the findings of this study and reports from Taiwan suggest that the
nonnative population of D. swinhonis in Hyuga City has a higher fecundity
than populations in Taiwan. It is therefore considered necessary to exterminate the
population in Hyuga City before this species colonizes other areas.
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Affiliation(s)
- Shoichiro Imatake
- Graduate School of Medicine and Veterinary Medicine, University of Miyazaki, Miyazaki 889-2192, Japan
| | - Noriko Imaizumi
- Laboratory of Veterinary Anatomy, Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan
| | - Yuki Ohashi
- Graduate School of Medicine and Veterinary Medicine, University of Miyazaki, Miyazaki 889-2192, Japan
| | - Hiroki Matsumura
- Laboratory of Veterinary Anatomy, Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan
| | - Marimu Urakawa
- Laboratory of Veterinary Anatomy, Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan
| | - Yugo Konaka
- Laboratory of Veterinary Anatomy, Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan
| | - Tetsuo Kida
- Laboratory of Veterinary Anatomy, Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan
| | - Tenya Yanagita
- Laboratory of Veterinary Anatomy, Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan
| | - Hinako Fujisaki
- Laboratory of Veterinary Anatomy, Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan
| | - Shoichi Wakitani
- Laboratory of Veterinary Anatomy, Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan
| | - Masahiro Yasuda
- Graduate School of Medicine and Veterinary Medicine, University of Miyazaki, Miyazaki 889-2192, Japan.,Laboratory of Veterinary Anatomy, Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan
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