Development of hypophysis and differentiation of its secretory cells at the early postembryonic development of silver carp Hypophthalmichthys molitrix (cyprinidae)

• Published in: Journal of ichthyology Vol. 46; no. 1; pp. 97 - 107
• Main Authors: Burlakov, A. B., Dobrynina, M. T., Medvedeva, A. A., Poluektova, O. G.
• Format: Journal Article
• Language: English
• Published: 01.01.2006
• Subjects: Cyprinidae; Freshwater; Hypophthalmichthys molitrix
• ISSN: 0032-9452; 1555-6425
• DOI: 10.1134/S0032945206010127

Silver carp Hypophthalmichthys molitrix hatches from the envelope at phase 19 a day after fecundation (water temperature 26-28 degree C) with body length 5.2 mm. The formation of hypophysis begins 7-8 h after hatching of the embryo. The first chromophilic cells (acidophiles in adenohypophysis) appear at the age of 9 days; the first basophilic cells (thyrotropocytes) at the age of 17-20 days, when juveniles are at stage III. The gonadotropic function is formed in the ontogenesis of silver carp at the age of 40-45 days, i.e., almost a month after the appearance of elementary sexual cells in the gonads. The differentiation of gonadotropocytes in mesoadenohypophysis to two functionally active types of cells (central and peripheral) is also completed by this time.