Bacterial infections in aquatic organisms pose a significant threat to shrimp aquaculture, often leading to production losses. In Pangandaran Regency, early shrimp harvesting is frequently practiced as a response to outbreaks. Previous studies have documented Vibrio and non‐Vibrio bacteria in pond water and sediments at five stations, but infections in shrimp tissues remain less explored. This study aimed to identify pathogenic Vibrio species in vannamei shrimp ( Litopenaeus vannamei ) and wild black tiger shrimp ( Penaeus monodon ), examine toxin genes, and quantify bacterial abundance. Samples were collected from five stations and analyzed using culture media, Gram staining and Polymerase Chain Reaction (PCR). Vibrio parahaemolyticus and Vibrio alginolyticus were detected at Stations 1 and 5, whereas only V. alginolyticus appeared at Stations 2, 3 and 4. Station 1 showed the highest Vibrio abundance (1.3767 × 10 ⁶ CFU/g), while Station 3 recorded the lowest (0.009 × 10 ⁶ CFU/g), with significant differences ( p < 0.05). Non‐Vibrio bacteria dominated most stations, except at Station 1 where Vibrio species were predominant. Toxin gene analysis revealed toxR in some isolates, while tdh, trh, pirA and pirB were absent. These findings emphasize the importance of bacterial and genetic monitoring to improve disease surveillance and support sustainable shrimp aquaculture.

In Pangandaran Regency, shrimp farming ponds are established along a 91km coastline, but premature harvests often occur due to shrimp diseases. The environmental conditions of shrimp ponds play a critical role in shrimp health and productivity. However, research on bacterial pollution in shrimp farming environments is lacking. This study aimed to identify bacterial species and their abundance in shrimp pond water, seawater, and sediment compared to coastal areas without shrimp farming. Bacterial identification was conducted through a survey across five stations, using NA and TCBS media, staining, and PCR techniques. Results showed that the highest bacterial count on NA in sediment was 2.854×10⁷ CFU/g, and the lowest in pond water was 0.658×10⁷ CFU/ml. On TCBS media, sediment had the highest concentration (0.1692×10⁷ CFU/g), while pond water had the lowest (0.0017×10⁷ CFU/ml). The bacterial abundance on NA media was significantly higher than on TCBS. Isolated bacteria included both Gram-negative and positive types, with various shapes (rod, comma, coccus). Specific bacteria identified were Bacillus flexus in semi-intensive pond water, Bacillus albus in intensive pond water, Vibrio fluvialis in semi-intensive pond sediment, Vibrio alginolyticus in intensive pond sediment, and Bacillus sp. in probiotics used by farmers. In addition, pathogenic bacteria were detected in the shrimp farming ecosystem of Pangandaran.

Bacillus subtilis is recognized as a probiotic bacterium with the potential to enhance fish immunity through the production of antimicrobial peptides (AMPs). This study evaluated a strain of B. subtilis isolated from fish intestines in previous research, designated as Bacillus CgM22, which has the potential to act as a probiotic and immunostimulant. Therefore, further research is needed to analyze the AMPs gene in Bacillus CgM22 at the molecular level and to assess the expression of the toll-like receptor (TLR2) gene in the kidneys and livers of carp following induction. The study involved molecular analysis of the AMPs gene, followed by induction in carp. The experiment included four treatments: A (control), B (bacterial culture at 10⁸ CFU/mLat 15 mL/kg feed), C (5 mL/kg supernatant), and D (10 mL/kg supernatant), each with three replicates, where the treatments were mixed into the feed. Afterward, liver and kidney samples were analyzed for TLR2 gene expression. The results indicated the presence of surfactin and subtilin markers, with the detection of several AMPs genes, including SrfAA (surfactin) and SpaS (subtilin). The highest TLR2 gene expression in kidney and liver samples was observed in treatment B (addition of Bacillus CgM22 culture at 10⁸ CFU/mL at 15mL/ kg feed). These findings suggest that Bacillus CgM22 plays a role in modulating fish immunity by enhancing the body's defense mechanisms against pathogens. Overall, this study indicates that B. subtilisCgM22 has potential as a probiotic alternative to improve carp health through immune stimulation.

The freeze-thaw process in sperm cryopreservation generates reactive oxygen species (ROS) that impair motility, viability, and fertilizing capacity in fish, including the Javan barb (Systomus rubripinnis), an endemic Indonesian cyprinid of conservation concern. This study evaluated five natural antioxidants: basil leaf extract (BLE), noni fruit extract (NFE), moringa leaf extract (MLE), sambiloto leaf extract (SLE), and honey-egg yolk (HEY). Radical-scavenging capacity was measured by DPPH assay (IC₅₀: BLE 134.06, MLE 297.04, NFE 422.86, SLE 3010.46 ppm), and post-thaw motility, duration of motility, viability, abnormality, fertilization rate, and ATP bioluminescence were assessed. Optimum doses were 1% for BLE, NFE, and MLE, 1.25% for HEY, and 7% for SLE. BLE at 1% gave the best overall profile (motility 85.15 ± 0.88%; duration 7.14 ± 0.38 min; viability 82.21 ± 1.86%; abnormality 18.29 ± 0.16%), significantly exceeding the control (65.00 ± 2.31%; 4.56 ± 0.33 min; 68.00 ± 2.42%; 23.54 ± 0.28%; p < 0.05), whereas SLE sustained the longest motility. All extracts supported fertilization rates above 82% versus 70.08 ± 3.82% in the control, and 1% BLE preserved post-thaw luminescence equivalent to fresh sperm (165,217 vs. 164,087 RLU), interpreted comparatively. These plant-derived antioxidants are promising supplements for Javan barb germplasm conservation.

Microbial conditions within sea turtle nesting environments may influence egg health and hatching outcomes, yet information on culturable bacteria associated with sea turtle eggs and nest sediments in Indonesia remains limited. This study characterized culturable bacteria from eggshell surfaces of green turtles ( Chelonia mydas ), olive ridley turtles ( Lepidochelys olivacea ), unhatched eggs, and natural and seminatural hatchery sediments at Batu Hiu Beach, Pangandaran, Indonesia. Three eggs were sampled from each egg category, with eggs within each category originating from the same nest. Bacterial recovery was evaluated using selective and non‐selective media, followed by colony characterization, Gram staining, and 16S rRNA sequencing of 21 representative isolates. Vibrio‐related isolates were screened for toxR, tdh, and trh genes using PCR. Green turtle eggshell swabs showed the highest mean culturable bacterial count (2,358 C F U / m L ), followed by olive ridley eggshell swabs (1,640 C F U / m L ), whereasile hatchery sediment showed the lowest mean count (109 CFU/mL). Bacterial recovery differed among culture media (Friedman χ 2 = 10.47, p = 0.0332; Kendall′’s W = 0.436). Molecular analysis showed affiliations with Enterobacteriaceae, Vibrio, and other environmental bacterial groups. All five Vibrio‐related isolates were positive for toxR, whereas tdh and trh were not detected.