Fish represent an excellent source of animal protein as well as a biomedical research model as a result of their evolutionary relatedness and similarity with the human genome. Commercial and ornamental fish culture has achieved popularity, but reproductive dysfunctions act as a limiting factor for quality fry production, interfering with the sustainability of the aquaculture industry. Fish reproduction is crucial for any species’ existence, and reproductive performance can potentially be improved through applications of epigenetics and probiotics. Epigenetics is a highly sensitive molecular approach that includes chromatin structure and function alteration, DNA methylation, and modification of non-coding RNA molecules for the transfer of desired information from parents to offspring. DNA methyltransferase improves reproductive cyp11a1, esr2b, and figla gene expression and feminizes zebrafish (Danio rerio). Moreover, epigenetics also contributes to genome stability, environmental plasticity, and embryonic development. However, methylation of specific genes can negatively affect sperm quality, resulting in poor fertilization. Probiotic administration is able to induce responsiveness of incompetent follicles to maturation-inducing hormones and can change oocyte chemical composition during vitellogenic development. The positive role of probiotics on testicular cells is validated by upregulating the transcription levels of leptin, bdnf, and dmrt1 genes facilitating the spermatogenesis. This review not only discusses the effects and mechanism of epigenetics and probiotics for improving fish reproduction, but also presents an overview of the causal factors and current techniques used to eradicate dysfunction. Moreover, key genes and hormones related to fish reproduction along with research gaps and future prospects are also considered. This review provides an overview of necessary information for students, scientists, researchers, and breeders to resolve fish reproduction-related problems to ensure profitable and sustainable aquaculture.

Nowadays there is a growing trend towards carotenoids obtained from natural sources such as microalgae. Dunaliella salina is among the most significant natural sources of beta-carotene for commercial scale, which is used in many food industries. Enzymatic extraction of beta-carotene is one of the safe methods that ensure that the food product is not contaminated compared to ex-traction using solvents. In this study, beta-carotene was extracted using two methods: the organic solvent method by tetrahydrofuran and the enzymatic extraction using a bacterial lipase enzyme. The alga was exposed to different stress conditions (salinity/nitrogen) for increasing the beta-carotene production. The highest value of beta-carotene content was recorded in the extraction method using tetrahydrofuran (109.008 µg/mL at 2.5M NaCl/0.5 g/L KNO₃), compared to the extraction method using lipase enzyme (19.13 µg/mL at 1 mg/mL at 24 h exposure time). However, the beta-carotene yield slightly increased (21.4 µg/mL) in lipase enzyme extraction method for the algal samples exposed to more than 24 h under different conditions (3M NaCl/1g/L KNO₃). The results show that the enzymatic extraction method is less efficient in extracting beta-carotene compared to the tetrahydrofuran solvent extraction method, with the latter showing a higher content of extracted beta-carotene.

Pangpang Bay is a wetland with mangrove forests, covering an area of more than 3,000 ha, which has been designated as an Indonesian Essential Ecological Area to maintain its high floral and faunal diversity. However, land-use changes and anthropogenic pressure from surrounding areas have caused changes in its biodiversity and community structures, including those of macrobenthic fauna. This study was conducted to determine the current environmental characteristics of Pangpang Bay and their influence on indicator organisms, such as macrobenthos. Eight stations were selected based on their geographical locations, macrobenthic fauna, physicochemical parameters, heavy metal concentrations, and sediment types to represent the entire Pangpang Bay. Results revealed that Pangpang Bay was strongly influenced by the sea. There were no significant differences among the sediment characteristics at all stations, which were all mud. Polychaetes were dominant at stations with muddy characteristics. Furthermore, the physicochemical parameters of water affected macrobenthic diversity and dominance. In contrast, the concentrations of heavy metals, such as Pb, Cu, Cd, and Fe were below the threshold values at all stations. Therefore, they did not affect macrobenthic diversity.

Cyanobacteria are well-distributed, because of their ability to acclimate to various environments. Recently, cyanobacteria have received more research attention due to increasing pollution problems and global warming. They have many potential applications in the biotechnology sectors such as pharmaceuticals, bioplastics production, and cosmetics. Cyanobacteria produce many biologically active compounds that are utilized as anti-inflammatory, antiviral, antibacterial, and antifungal agents. The bioactive metabolites extracted from cyanobacteria include alkaloids, fatty acids, lipopeptides, and amides. In this minireview, the potential of some biotechnical applications are summarized to provide an account of the recent advancements in cyanobacteria research.