Observation of reproductive cycles of female Ocadia sinensis with radiology and ultrasonography
Date Issued
2005
Date
2005
Author(s)
Hsieh, Chung-Wei
DOI
zh-TW
Abstract
Except Ocadia sinensis, all of the freshwater turtles were listed as protected animals in Taiwan. Recently, utilization on land was changed and over 70% rivers and ponds where the freshwater turtles inhabit in was engineered. The bank of rivers and brooks were replaced with cement and it caused the habitats of freshwater turtles disappear rapidly. The disappearance of habitats cause the numbers of freshwater turtles decrease dramatically. Ocadia sinensis was also in the dangerous situation. The invasion of foreign species and the excess capture of wild turtles owing to the need of bone plate were also made Ocadia sinensis disappear rapidly.
There were few researchs about reproductive cycle of Ocadia sinensis. To study the reproductive stage of Ocadia sinensis not only help realize the reproductive physiology but also could apply to the conservation. Realize the impaction on reproductive physiology under changing the river bank, and it could be refered to river engineering for conservation freshwater turtles.
From March of 2004 to August of 2005, the experiment has detected 11 turtles and another 11 turtles which were added in October of 2004. The experiment methods were that detected the largest follicular follicles with noninvasive ultrasound and radiology was also involved. The detection methods could realize the the growth of follicles, ovulation and atrophic follicles. It also could find the process from the ovum to hard-shell egg and the situation of oviposition.
According to the result, the follicles of gravid turtles grew on September, and became preovulatory follicles (16.6 ± 0.4mm) among November to December. Ovulation occured
among February to March when the temperature rose again from minimum. Before and after ovulation, the follicular diameters were 18.0 ± 0.9 mm and 17.5 ± 1.3 mm respectively.
Oviposition was completed among April to June. Before and after oviposition, the follicular diameters were 18.5 ± 1.1 mm and 17.2 ± 1.5 mm respectively. The latent period after ovipostion which follicles appeared atrophic among April to August. The minimum diameter of follicles was 9.4 ± 1.6 mm. After the latent period the reproductive cycle
recycled. Seven out of eleven turtles were gravid and laid a total of 65 eggs in the reproductive cycle of 2004. The average clutch size was 9.3 ± 1.7 eggs (N=7. range 6-11
eggs). Nineteen out of twenty-two turtles were gravid and laid a total of 223 eggs in reproductive cycle of 2005. Eight out of nineteen turtles which were gravid laid second
clutch. Clutch size was 8.3 ± 2.3 (N=22, range 1-13 eggs). The gravid turtles average laid 1.4 (27/19) clutches per year. According the result of daily detection with ultrasound, there was no change of the image of preovulatory follicles just before ovulation. It takes 24-48 hrs to complete ovulation. Fifth to sixth day after the ovulation, the light egg outline started to be found on radiology. In the radiology, there were two type of egg shell with different thickness. It was the direct evidence of gravid turtles laid second clutch. There was no difference in average body weight of group when turtles in different reproductive status.
According my search for paper of Ocadia sinensis, there were few papers about Ocadia sinensis. And no research of reproductive cycles of Ocadia sinensis with ultrasound
was found . Detection the change of the follicles of largest group, it not only could help to realize the ovarian cycle of Ocadia sinensis but also support the basis of reproductive physiology to study wild group. The finding of radiological image of second clutch and the
timing contrast between radiology and ultrasound during the ovulation process could provide references to study reproductive cycle of chelonian. The detection methods were
noninvasive and reliable, and it also gave consideration to convenience and practicality. These detection models with ultrasonography could be applied to set up the reproductive physiology of other freshwater turtles.
The study was extremely valuable while studying the reproductive models of Ocadia sinensis, taking conservative concerns and engineering of river.
Subjects
斑龜
生殖週期
超音波
放射線學
Ocadia sinensis
reproductive cycles
radiology
ultrasonography
Type
thesis
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