Unraveling the Complexities of Fish Reproductive Physiology: From Molecules to Ecosystems

Dear Colleagues,

Reproduction is not merely a physiological process, it is the foundation of life itself, underpinning the continuity of species across unicellular and multicellular organisms. Among vertebrates, fishes represent the most diverse and abundant group, offering a rich framework for the investigation of the intricate mechanisms and evolutionary innovations underlying reproductive strategies.

Sexual reproduction, driven by meiosis—particularly through crossing-over and independent chromosome segregation—ensures genetic diversity, fueling adaptability and evolutionary success in species. In fishes, this diversity is reflected in a remarkable array of reproductive modalities: while gonochorism predominates, numerous species exhibit hermaphroditism in various forms. These include juvenile hermaphroditism (Danio rerio), sequential hermaphroditism—protandry (Sparus aurata) and protogyny (Thalassoma bifasciatum)—and even simultaneous hermaphroditism (Kryptolebias marmoratus).

Fish reproductive functions are tightly orchestrated by environmental signals transduced through the neuroendocrine axis, ultimately modulating the pituitary release of follicle-stimulating hormone (Fsh) and luteinizing hormone (Lh). These gonadotropins act on specific receptors in gonadal somatic cells, regulating steroidogenesis, local growth factor expression, and, as has been more recently identified, non-coding RNA networks, including microRNAs and long non-coding RNAs.

This Special Issue will bring together cutting-edge research and comprehensive reviews exploring both fundamental and applied dimensions of reproductive physiology in fishes. We welcome submissions on a wide range of topics, including the following:

• The molecular and endocrine regulation of gametogenesis;
• The integration of multi-omics approaches (e.g., bulk and single-cell transcriptomics, proteomics, and epigenetics);
• The influence of environmental and social factors on puberty, fecundity, and gamete quality;
• Impacts of climate change and abiotic stressors on reproductive performance;
• Biotechnological innovations in reproductive manipulation:
• Germ cell transplantation,
• 3D gonadal cell cultures and organoid models,
• Bioengineering and bioprinting of reproductive tissues;
• Nutritional and husbandry strategies to enhance reproductive efficiency in aquaculture.

We particularly encourage contributions that combine classical physiology with contemporary approaches, as well as works with translational relevance to aquaculture, biodiversity conservation, and evolutionary biology.

We invite researchers from around the world to contribute to this Special Issue, building up a comprehensive and integrative understanding of reproductive physiology in fishes—the most diverse group of vertebrates on Earth. Join us in advancing the frontiers of knowledge in this fascinating and impactful field.

Dr. Rafael Nóbrega
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Fishes is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

• reproduction
• aquaculture
• ecology
• biotechnology
• endocrinology
• gonads
• sex
• spermatogenesis
• oogenesis
• gamete quality