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Vol. 47 No. 6, 2008
Cell Structure and Seasonal Changes of the Androgenic Gland of the Mud Crab Scylla paramamosain (Decapoda: Portunidae)
Hong Liu1,2, Kwok-Chu Cheung1, and Ka-Hou Chu1,*
1Department of Biology, Chinese University of Hong Kong, Shatin, Hong Kong, China
2Key Laboratory of Aquatic Genetic Resources and Aquacultural Ecology, Shanghai Ocean University, Shanghai, 200090, China
Hong Liu, Kwok-Chu Cheung, and Ka-Hou Chu (2008) In the mud crab, Scylla paramamosain,
the androgenic gland (AG) is an elongated structure, situated along the
posterior vas deferens. There are 3 types of cells (types I, II,
and III) in different seasons and in different parts of the AG of S. paramamosain.
They could be easily distinguished based on the cell size, relative
proportion of the nucleus in cells, and the abundance of
vacuoles. Type I cells are packed together in a high density and
have a small cell size, a relatively large nucleus, and a small amount
of cytoplasm. These are newly formed gland cells. Type II
cells represent the majority of AG cells with the highest activity
during the secretory cycle. They have much more cytoplasm with
bigger cell sizes than type I cells. Type III cells are
characterized by abundant vacuoles and the disappearance of cell
boundaries in some cases, which represent the degeneration stage of the
secretory cycle. In different seasons, there are significant
differences in terms of gland size, cell boundary, the presence of
multinucleated cells, and the occurrence of immature gland cells.
The size of the AG increased from January and reached a maximum in the
major mating season (July-Sept.). The AG began to degenerate in
Oct. In Nov., cell boundaries were difficult to locate. The
number of hemocytes greatly increased in Dec., indicating regeneration
of the AG. In Mar. to Apr. is a minor mating season, and some
spent testes were observed. The AG further developed to the next
major mating season. Therefore, the activity of the AG is
synchronized with the reproductive cycle.
Key words: Histology, Ultrastructure, Reproduction, Scylla paramamosain, Brachyura.
*Correspondence: Tel: 852-26096772. Fax: 852-26035391. E-mail:kahouchu@cuhk.edu.hk
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