Ovarian maturation and oogenesis in the blue swimmer crab, Portunus pelagicus (Decapoda: Portunidae)

Abstract

Ravi, R., Manisseri, M.K. and K.S., N. 2013. Ovarian maturation and oogenesis in the blue swimmer crab, Portunus pelagicus (Decapoda: Portunidae). -Acta Zoologica (Stockholm) 94: 291-299.The study was aimed at understanding the process of reproduction and the changes happening in the ovary of Portunus pelagicus during maturation, which would be useful for its broodstock development for hatchery purposes. For that, tissue samples from different regions of the ovary at various stages of maturation were subjected to light and electron microscopy, and based on the changes revealed and the differences in ovarian morphology, the ovary was divided into five stages such as immature (previtellogenic oocytes), early maturing (early vitellogenic oocytes), late maturing (late vitellogenic oocytes), mature (vitellogenic oocytes), and spent (resorbing oocytes). The ovarian wall comprised of an outermost thin pavement epithelium, a middle layer of connective tissue, and an innermost layer of germinal epithelium. The oocytes matured as they moved from the centrally placed germinal zone toward the ovarian wall. The peripheral arrangement of nucleolar materials and the high incidence of cell organelles during the initial stages indicated vitellogenesis I. Movement of follicle cells toward oocytes in the early maturing stage and low incidence of mitochondria and endoplasmic reticulum in the ooplasm during late vitellogenic stage marked the commencement and end of vitellogenesis II, respectively. Yolk granules at various stages of development were seen in the ooplasm from late vitellogenic stage onwards. The spent ovary had an area with resorbing oocytes and empty follicle cells denoting the end of one reproductive cycle and another area with oogonial cells and previtellogenic oocytes indicating the beginning of the next.

Morphology and ultrastructure of the somatic cells in Astacus leptodactylus ovary

“…and Panulirus sp. (Kessel 1968), Coenobita clypeatus (Komm and Hinsch, 1987), Portunus pelagicus (Ravi et al, 2013), and Procambarus fallax f. virginalis (Vogt et al, 2004). However, the presence of coated vesicles in our study both in previtellogenic and vitellogenic oocytes of A. leptodactylus, suggest that before the onset of vitellogenesis, follicle cells can deliver other substance into oocytes by receptor-mediated endocytosis.…”

“…and Panulirus sp . (Kessel ), Coenobita clypeatus (Komm and Hinsch, ), Portunus pelagicus (Ravi et al, ), and Procambarus fallax f . virginalis (Vogt et al, ).…”

“…A developing oocyte and the surrounding follicle cells around it represent the ovarian follicle (Talbot, , ) or oogenetic pouch (Ando and Makioka, ; Vogt et al, ; Mirheydari et al, ). Previous studies reported the presence of follicle cells around previtellogenic oocytes in Macrobrachium rosenbergii (Soonklang et al, ) and around vitellogenic oocytes in Homarus americanus (Kessel, ; Talbot, , ), Thenus orientalis (Dongfa et al, ), Portunus pelagicus (Ravi et al, ), Macrobrachium rosenbergii (Jugan and Zerbib, ; Soonklang et al, ), Astacus astacus (Durfort et al, ) and Procambarus fallax f . virginalis (Vogt et al, ) and also around mature oocytes in Macrobrachium rosenbergii (Ferreira et al, ).…”

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“…Minagawa et al (1993) reported the reproductive biology and the oocyte development in the red frog crab Ranina ranina. The light and electron microscopic details of oogenesis have been carried out in the blue swimmer crab Portunus pelagicus (Ravi et al, 2012). However, there is little information available on oocyte development and vitellogenesis in freshwater crabs (Joshi and Khanna, 1982).…”

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“…Vitellogenesis is the formation of yolk at oocyte in the ovary. Study by Ravi et al, (2013) showed that there were mobilization of FA from hepatopancreas to the ovary at vitellogenesis I and II (from Stage I to Stage III).…”