Oocyte Degeneration Associated with Follicle Cells in Female Mactra chinensis (Bivalvia: Mactridae)

Molecular Cytogenetics in Trough Shells (Mactridae, Bivalvia): Divergent GC-Rich Heterochromatin Content

The family Mactridae is composed of a diverse group of marine organisms, commonly known as trough shells or surf clams, which illustrate a global distribution. Although this family includes some of the most fished and cultured bivalve species, their chromosomes are poorly studied. In this work, we analyzed the chromosomes of Spisula solida, Spisula subtruncata and Mactra stultorum by means of f...

Ultrastructural Studies on Oocyte Development and Vitellogenesis associated with Follicle Cells in Female Scapharca subcrenata (Pelecypoda: Arcidae) in Western Korea

Ultrastructural studies on oocyte development and vitellogenesis in oocytes, and the functions of follicle cells during oogenesis and oocyte degeneration were investigated to clarifyb the reproductive mechanism on vitellogenesis of Scapharca subcrenata using electron microscope observations. In this study, vitellogenesis during oogenesis in the oocytes occured by way of autosynthesis and hetero...

External Ca2+ is predominantly used for cytoplasmic and nuclear Ca2+ increases in fertilized oocytes of the marine bivalve Mactra chinensis.

Oocytes of the marine bivalve Mactra chinensis are spawned and arrested at the germinal vesicle stage (first meiotic prophase) until fertilization, without undergoing a process called oocyte maturation. As is the case of other animals, a fertilized oocyte of the bivalve displays increases in intracellular free Ca(2+). We have clarified here the spatiotemporal patterns and sources of the intrace...

Short communication: Effects of induced spawning on early development in snout otter clam, Lutraria philippinarum (Deshayes, 1854) (Bivalvia: Mactridae)

Description of the ovarian follicle maturation of the migratory adult female bulatmai barbel (Luciobarbus capito,Güldenstädt 1772) in captivity

The study aimed to investigate the maturation process of ovarian follicles and ovary structure of migratory form of female Bulatmai barbel (Lucioarbus capito). The histology of oogenesis coincided with that known from most teleosts. The ovarian structure was found to be cytovarian. The development of the oocytes is started from early May along with spawning and the degeneration of matured oocyt...