International Journal of Aquaculture, 2024, Vol.14, No.3, 154-164 http://www.aquapublisher.com/index.php/ija 155 habitat loss, and other anthropogenic factors (Lee and Lou, 2019). Effective aquaculture practices are necessary to meet the demand for eel products and to reduce pressure on wild populations. Secondly, the unique life cycle of eels, which involves long migrations and complex developmental stages, poses significant challenges for conservation and aquaculture efforts (Hanzen et al., 2020). By improving our understanding of the reproductive mechanisms and growth processes in eels, researchers can develop strategies to enhance their reproductive success and ensure sustainable populations. This study aims to explore genomic and developmental approaches to enhance the reproductive success and growth of eel species. Specifically, it includes researching the hormonal regulation of key ovarian growth stages and their impact on reproductive success, evaluating the practicality of DNA barcoding in species identification, and its implications for conservation and aquaculture. Based on the findings from genomic and developmental research, the study will propose strategies to improve eel aquaculture practices. By addressing these objectives, we hope to contribute to the knowledge base of eel reproduction and growth, providing insights that can support conservation and aquaculture practices. 2 Genomic Approaches 2.1 Genomic sequencing and analysis Genomic sequencing and analysis are fundamental tools in understanding the genetic makeup of eels, which can significantly contribute to enhancing their reproductive success and growth. By sequencing the genome of eels, researchers can identify genetic variations and understand the genetic basis of traits related to growth and reproduction (Burgerhout et al., 2018). For instance, comprehensive expression analysis using quantitative real-time PCR and RNA sequencing has been employed to study the effects of phytoestrogens on sex differentiation in Japanese eels (Anguilla japonica). This approach revealed that genistein, a soy isoflavone, induces feminization by altering the expression of sex-specific genes, thereby providing insights into the molecular mechanisms of sex differentiation in eels (Inaba et al., 2022). 2.2 Identification of key genes Identifying key genes involved in reproductive processes and growth is crucial for developing strategies to enhance these traits in eels. The study on Japanese eels demonstrated that genistein up-regulates female-specific genes and down-regulates male-specific genes in the gonads, suggesting that these genes play a significant role in sex differentiation. Such findings can be leveraged to manipulate the sex ratio in eel populations, favoring the production of females, which have higher commercial value due to their greater body weight (Inaba et al., 2022). Additionally, the use of recombinant gonadotropins in European eels (Anguilla anguilla) has shown that specific hormones can induce spermatogenesis and spermiation, highlighting the importance of hormonal regulation in reproductive success (Peñaranda et al., 2018; Kottmann et al., 2021). 2.3 Genomic selection techniques Genomic selection techniques involve using genetic information to select individuals with desirable traits for breeding. This approach can accelerate the improvement of growth and reproductive traits in eel populations. By integrating genomic data with traditional breeding methods, it is possible to enhance the efficiency and accuracy of selection. For example, the identification of sex-specific genes and their expression patterns in Japanese eels can be used to develop genomic selection strategies aimed at increasing the proportion of females in aquaculture settings (Inaba et al., 2022). Similarly, the application of recombinant gonadotropins in European eels demonstrates the potential of combining genomic and hormonal approaches to optimize reproductive outcomes (Peñaranda et al., 2018; Kottmann et al., 2020). 3 Developmental Approaches 3.1 Hormonal regulation of reproduction Hormonal regulation plays a pivotal role in orchestrating the reproductive cycle of eels, from gonadal maturation to spawning. Key hormones, such as gonadotropins and sex steroids, govern critical stages of reproductive development (Burgerhout et al., 2018; Peñaranda et al., 2018). One significant approach involves the use of
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