Fish ovaries exhibit a remarkable diversity in
shape, size, and organization, reflecting the myriad
reproductive strategies employed by different species.
This review delves into the intricate biology of fish
ovaries, highlighting their structural diversity and the
hormonal regulation that governs ovarian development
and oocyte maturation. Key hormones include pituitary
gonadotropins (GTHs) and maturation-inducing
hormones (MIHs), which initiate oocyte growth and
maturation. GTHs stimulate ovarian production of
estradiol-17β and 17α,20β-DP, which induce oocyte
maturation via MPF formation. Sex steroids like
estrogens and progestogens, synthesized from
cholesterol, play crucial roles. Other hormones,
including growth hormone, prolactin, thyroid hormones,
IGFs, ACTH, and melatonin, influence ovarian activity.
The review also explores the varied reproductive
strategies among fish, including oviparity and viviparity,
and discusses how environmental factors like water
temperature and photoperiod influence ovarian
histology. Understanding the complex interplay between
these factors is essential for advancing fisheries
management, conservation, and aquaculture practices.
Additionally, the evolutionary trajectory of fish ovaries
underscores their adaptation to diverse ecological niches,
contributing to the survival and reproductive success of
fish species. The ovarian stroma provides structural
support and houses various cell types, including
dendritic cells (DCs), endocrine cells, and telocytes,
contributing to follicle growth and hormone production,
essential for reproductive success in fish. Fish ovaries
are a crucial aspect of fish biology, with their structure
and function intricately regulated by hormonal,
environmental, and seasonal factors.