Structure and development of reproductive system in Achatina fulica
Issued Date
2024
Copyright Date
1988
Resource Type
Language
eng
File Type
application/pdf
No. of Pages/File Size
xv, 206 leaves : ill.
Access Rights
open access
Rights
ผลงานนี้เป็นลิขสิทธิ์ของมหาวิทยาลัยมหิดล ขอสงวนไว้สำหรับเพื่อการศึกษาเท่านั้น ต้องอ้างอิงแหล่งที่มา ห้ามดัดแปลงเนื้อหา และห้ามนำไปใช้เพื่อการค้า
Rights Holder(s)
Mahidol University
Bibliographic Citation
Thesis (M.Sc. (Anatomy))--Mahidol University, 1988
Suggested Citation
Udomsri Ngowsiri Structure and development of reproductive system in Achatina fulica. Thesis (M.Sc. (Anatomy))--Mahidol University, 1988. Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/100265
Title
Structure and development of reproductive system in Achatina fulica
Alternative Title(s)
โครงสร้างและการพัฒนาของระบบสืบพันธุ์ ในหอยทากยักษ์ (แอคาไทนา ฟูลิคา)
Author(s)
Abstract
The morphology of ovotestis, prostate gland, uterus and dalbumen gland of Achatina fulica were studied by light microscopy (LM). They were fixed in Bouins fluid and processed for (LM). It was found that ovotestis consisted of spermatogenic cells, oocytes, Sertoli cells and follicle cells. Prostate gland contains two distinct types of cells characterized by their affinity to staining. The first type is the gland cell with eosinophilice granules while the secoud type consists of clear granules. Uterus is characterized by a long tube. Its wall is divided into three layers ; the inner layer is ciliated epithelium; the middle layer is adipose tissue and the outer is of muscular layer. Albumen gland composes of a large number of follicles which open into the main duct. The ultrastructure of ovotestis and ovotestis duct were investigated by scanning and transmission electron microscopy (SEM,TEM). They were fixed with 2.5% glutaraldehyde in 0.1 M sodium cacodylate buffer pH 7.4 and processed for SEM and TEM. Ovotestis consists of the round and different sizes of spermatogenic cells. The clump of spermatozoa with long tail and cytoplasmic knobs are observed. Spermatogonia and spermatocytes are located towards the base of the acini in close association with Sertoli cells. Spermatocytes are large cells that have nuclei which show numerous clumps of highly condensed heterochromatin along the nuclear evelope. Spermatide could be classified into four stages based on the shape, the echromatin appearance, the organization and distribution of cell organells. Stagel spermatid is characterized by the small and uniformly-dense nucleus, the cell size is larger than spermatocyte. Stage II spermatid has a small nucleus with similer chromatin appearance as in stagel. Mitochondria are concentrated towards one side or the cell. Stagelll spermatid contains the cap-shaped nucleus whose chromatin is still evenly distributed. Nucleus, mitochondria and Golgi complex are clearly iocalized in different zones of the cytoplasm. In later stage the capshape nucleus is elongated further and embraced around the centriolar area. The cell is also elongated and exoneme core is formed. The cluster of mitochondria begin to reorient longitudinally and wrap around the axoneme cors. StageIV spermatid is characterized by the cone-shaped nucleus that contains dense chromatin rods closely packed together with narrow intervening spaces. Spermatozoon is characterized by the elongated head and tail and mitochondrial sheath. The nucleus shows completely condensed chromatin. No cytoplasm is found in all part of both mid-piece and the tail. The structure of mature spermatozoon in ovotestis duct can be divided into head, mid-piece and tail regions. The head is cone-shaped. The mid-piece is composed of two spiral columns ; namely in the flagellum and the mitochondrial keels. The tail is divided into three parts based on its diameter and the internal ultrastructures. The development of ovotestis in from hatching to 1 year old stages was studies by light microscopy. It was found that ovotestis was firstly appeared in three-month sold. it is composed of many acini seperated by surrounding connective tissue. Each acinus contains various stages of developing germ cells ; namely, spermatogonia, primary spermatocytes, spermatide and spermatozoa. In some acini, the group of sperm heads adhered to Sertoli cells are observed. These morphological characteristice were also observed in three months snails and in the later stages of maturity. It is therefore suggested that spermatogenesis in Achatina fulica begins at three-months old, and that spermatogensis in each acinus is produced in cycle. On the other hand, the large oocytes are firstly observed at five months old. They are often located at the periphery of acini and progessively increased in number as snails reach seven to eight months old. After this age, the number of oocytes are decreased. It is also interesting to note that the male phase of snail develops early in life while the female phase of the same organism arised later. The effect of seasonal change on the number of oocytes per acinus was studies by LM. Ovotestis obtained from greenhouse and field were fixed in Bouin fluid and processed for LM. It was found that the number of oocytes per acinus collected from both the field and greenhouse are highest in May and September and lowest in March. However, the number of oocytes per acinus obtained from the greenhouse is higher than the snail collected from the field. In contrast, spermatozoa are produced concurently all the year.
Description
Anatomy (Mahidol University 1988)
Degree Name
Master of Science
Degree Level
Master's degree
Degree Department
Faculty of Science
Degree Discipline
Anatomy
Degree Grantor(s)
Mahidol University