This study aimed to evaluate the effectiveness of clove oil as a natural anesthetic for Batak fish juveniles during transportation. The experiment was conducted using a Completely Randomized Design (CRD) with four treatment levels of clove oil: P0 (control/0 ml/l), P1 (0.01 ml/l), P2 (0.02 ml/l), and P3 (0.03 ml/l), each with three replicates. Observed parameters included physiological responses (induction time, recovery time, and behavior), survival rate, and water quality before and after transportation. The results indicated that clove oil significantly affected the physiological responses of Batak fish juveniles, although it did not significantly influence survival rates, which remained above 90% for all treatments. The optimal concentration was 0.01 ml/L, with an average induction time of 64 minutes and recovery time of 1.15 minutes. During transportation, water temperature increased from 27.48 °C to 29.53 °C, pH decreased from 7.22 to 7.17, and dissolved oxygen (DO) decreased from 5.38 mg/l to 5.32 mg/l. These changes remained within the tolerance range of Batak fish juveniles, thus not affecting survival. The findings demonstrate that clove oil effectively reduces physiological stress and maintains water quality, suggesting that it can be recommended as a safe, efficient, and environmentally friendly natural anesthetic for transporting Batak fish juveniles. Keywords: Anesthesia; Clove Oil; Survival Rate; Tor soro; Transportation

Asian redtail catfish (Hemibagrus nemurus) is one of the freshwater fish commodities with high economic value and already cultivated in Riau Province. Food that is given does not fully all the nutrition needed for larvae growth. One way to improve the feed quality is to enrich it with fish oil. This study aimed to determine the best oil sources in feed on the growth and survival rate of larvae. This research was conducted from August to September 2023 at the Fish Hatchery and Breeding Laboratory, Faculty of Fisheries and Marine Science, University of Riau. This study used the experimental method of Completely Randomized Design (CRD) with 5 treatments and 3 replicates. The treatments used were P1 (commercial feed,) P2 (shark oil 8%), P3 (pangasius catfish 8%), P4 (squid oil 8%), and P5(cod liver oil 8%). Larvae were reared for 40 days with a stocking density of 5 individuals/L. The result of the research showed that enrichment feed with different oil sources had a significant effect (P<0,05) on the growth of absolute weight, absolute length, specific growth rate, and survival rate. Enrichment of feed with squid oil results the higher growth than the other treatments with absolute weight of 0,71 g, absolute length of 3,06 cm, specific growth rate of 14,03%/day, and survival rate of 68,00%. Larvae’s response to feeding was very aggressive and nothing was left. Water quality parameters during the study were still in the good category for Asian redtail catfish with temperatures 28,7-30,1°C, pH 6,5-6,8 and dissolved oxygen 4,0-5,3 mg/l. Keywords: Asian Redtail Catfish Larvae; Enrichment food; Growth; Survival rate

This study aims to examine the effect of probiotic (Probio-7) supplementation on the Specific Growth Rate (SGR), Feed Conversion Ratio (FCR), and Survival Rate (SR) of Nile tilapia (Oreochromis niloticus). The research was conducted from January to March 2025 at the UNU Purwokerto Laboratory. An experimental method was used with a completely randomized design (CRD), consisting of 4 treatments and 3 replications. The treatments were: P1 (feed without probiotics), P2 (feed with 8 ml/kg probiotic), P3 (feed with 10 ml/kg probiotic), and P4 (feed with 12 ml/kg probiotic). The fish used were Nile tilapia (Oreochromis niloticus) with an average length of 6.53±0.35 cm and an average weight of 2.28±0.02 g. Feed was given at 08:00 and 16:00 until satiation. Stocking density was 15 fish per container filled with 15 liters of water, and the maintenance lasted for 30 days. The feed used was commercial pellet feed supplemented with probiotics according to the treatment, containing 32% protein. The results showed that the addition of probiotics (Probio-7) had a significant effect (P<0.05) on Specific Growth Rate (SGR), Feed Conversion Ratio (FCR), and Survival Rate (SR). Treatment P4 had the highest SGR value of 2.08±0.03 g, the lowest FCR of 0.33±0.02, and the highest Survival Rate (SR) of 84±7%. Keywords: Feed Conversion Ratio; Tilapia; Probiotics; Survival Rate

This study presents a preliminary assessment of opisthobranch sea slug diversity in the coastal waters of Erdemli-Akkum, located in Mersin Bay (Eastern Mediterranean, Türkiye). During exploratory scuba dives conducted between 2014 and 2015, seven species belonging to different opisthobranch groups were observed and photographed across a range of marine biotopes, including rocky substrates, sandy bottoms, and macroalgal assemblages. The recorded taxa include Goniobranchus annulatus, Flabellina rubrolineata, Flabellina affinis, Cratena peregrina, Elysia viridis, Aplysia depilans, and Syphonota geographica. These species represent a broad ecological and morphological diversity within the subclass Heterobranchia. The findings contribute to the growing faunistic inventory of opisthobranchs in the Eastern Mediterranean and highlight the ecological richness of the Akkum coastal area. The use of in situ photography proved valuable for documentation and visual identification, supporting future taxonomic and ecological studies. Keywords: Eastern Mediterranean; Mersin Bay; Nudibranchs; Opisthobranchia; Photographic records

Mitochondrial DNA (mtDNA)-based genetic analysis is important for revealing evolutionary relationships, supporting taxonomy, and providing a basis for conservation management. This study was conducted in the waters of Aceh Jaya and West Aceh, two regions with high shark fishing activity but minimal genetic data. A total of 12 shark individuals (6 per location) were collected from fish landing ports, then dorsal muscle tissue was taken, preserved in ethanol, and analyzed using DNA extraction, sequencing, and bioinformatics methods. Molecular identification through comparison with GenBank showed a very high level of similarity (Query Cover 99–100%, Identity 100%), with detected species including Carcharhinus falciformis, Sphyrna lewini, and Hemigaleus microstoma, reflecting a wide distribution in the western waters of Aceh. The nucleotide composition showed a dominance of thymine bases and a higher A+T ratio than G+C, consistent with the characteristics of shark genomes. Phylogenetic analysis showed a monophyletic clade with strong bootstrap support (100%) and placed S. lewini as the earliest differentiated taxon. Our results confirm the efficacy of DNA barcoding for accurate species identification and genetic diversity mapping, while underscoring urgent conservation concerns, as most species identified are classified as Vulnerable to Critically Endangered on the IUCN Red List. Keywords: Aceh; DNA Barcoding; Genetic Variation; Phylogenetics; Sharks

This study aimed to identify the concentration of heavy metals, lead (Pb) and cadmium (Cd), in sediments and oysters (Bivalvia), as well as to examine their relationship with mangrove ecosystem characteristics in Kuala Ceurape (Bireuen) and Udeung Village (Pidie Jaya). Heavy metal concentrations were analyzed using the Indonesian National Standard (SNI) methods, while mangrove species identification was conducted through field vegetation surveys. The results showed that Pb concentrations in sediments ranged from 3.67–15.29 mg/kg with an average of 7.38 mg/kg in Udeung and 8.65 mg/kg in Kuala Ceurape. Cd concentrations in sediments were higher, ranging from 4.69–11.95 mg/kg (average 7.38 mg/kg) in Udeung and 3.54–11.69 mg/kg (average 8.65 mg/kg) in Kuala Ceurape. In oysters, Pb concentrations were recorded at 4.36–9.53 mg/kg in Udeung and 2.16–6.71 mg/kg in Kuala Ceurape, while Cd showed greater accumulation, reaching 17.07–18.13 mg/kg (average 12.71 mg/kg) in Udeung and 1.96–11.21 mg/kg (average 5.16 mg/kg) in Kuala Ceurape. Compared to FAO/WHO and CCME standards, Pb levels in sediments remained below the threshold, but Pb and Cd in oysters and Cd in sediments exceeded safe limits. Vegetation identification indicated the dominance of Rhizophora apiculata, which plays an important role in heavy metal trapping. These findings suggest that mangrove ecosystems function as natural filters of heavy metals, yet bioaccumulation in edible biota such as oysters may pose potential health risks to coastal communities. Keywords: Bioaccumulation; Cd; Mangrove; Oyster; Pb; Sediment

The eutrophic conditions of Rawa Pening waters results in the rapid growth of water hyacinth (Eichhornia crassipes). The uncontrolled presence of water hyacinth affects the intensity of sunlight entering the water column and affects plankton abundance. The purpose of this study was to determine the vertical distribution of plankton abundance, the main factors affecting plankton abundance, and plankton associated with light intensity. The study was conducted in January and July 2024 using survey methods, with a total of 3 stations and 2 depths (0 m and 1 m). The statistical analysis used was the t-test and simple linear regression, Pearson correlation test, and multivariate analysis using Nonmetric Multidimensional Scaling (NMDS) with envfit analysis. The results showed that depth did not significantly affect the abundance of phytoplankton and zooplankton, but sampling time in January and July had an effect on the abundance of phytoplankton. The types of phytoplankton found were Chloropyceae, Bacillariophyceae, Cyanophyceae, Zygnematophyceae, Trebouxiophyceae, Euglenophyceae, and Chrysophyceae, while the zooplankton found were Monogononta, Branchiopoda, and Maxillopoda. Phytoplankton abundance values ranged from 740,447 - 3,650,523 cells/L, while zooplankton abundance ranged from 0 - 3,335 ind/L. There was no significant (homogeneous) relationship between light intensity and phytoplankton abundance based on the results of NMDS and envfit association analysis. Nitrate levels significantly affected plankton abundance based on the r value (0.901) and R2 (0.812). Keywords: Abundance, Envfit, Plankton, Rawa Pening, Vertical Distribution

This study aims to analyze the influence of fuel prices (BBM) and sea wave height on the price of mackarel tuna in Banda Aceh City, with a case study at the Ocean Fisheries Port (PPS) Kutaraja Lampulo. The study uses monthly secondary data from 2019 to 2024 and applies a Linear Regression Model for analysis. The regression results indicate that both fuel prices and sea wave height have a significant effect on mackarel tuna prices at the 0.05 significance level. The wave height variable shows a positive coefficient, indicating that higher waves tend to increase mackarel tuna prices. This finding is consistent with the theory that extreme sea conditions hinder fishing activities, reduce fish supply, and consequently increase prices. However, the fuel price variable shows a negative coefficient, contrary to the economic theory that rising fuel prices should increase commodity prices due to higher production costs. This result is likely due to the stability of fuel prices (diesel fuel) during the observation period and the operational efficiency achieved through the use of technology by fishermen, allowing them to maintain or even improve catch volumes despite rising fuel prices. Keywords: Fuel Price; Mackarel Tuna Price; Wave Height

Way Kuala River is one of the rivers located in urban areas and utilized by various activities around it. Waste from the activities of the surrounding community that was discharged directly into the river will cause a decrease in river water quality. A decrease in water quality can be indicated by changes in physical, chemical, and biological parameters. The purpose of this research is to analyze water quality conditions and determine the water quality status of Way Kuala River, Bandar Lampung City. This research was conducted in November 2024-January 2025 in Way Kuala River, Bandar Lampung City. Sampling was conducted at 3 stations along the Way Kuala River using a direct survey method. Samples were then analyzed in situ, namely direct analysis in the field and ex situ with analysis at the BSPJI Bandar Lampung Laboratory. The data analysis used is STORET, pollution index (IP), and canadian council of ministers of the environment (CCME WQI). The results showed that the condition of Way Kuala River was categorized as polluted. The water quality status of Way Kuala River with STORET tends to be heavily polluted. The water quality status of Way Kuala River with IP tends to be lightly polluted. The water quality status of Way Kuala River with CCME WQI tends to be less polluted. Keywords: CCME WQI; Pollution Index; STORET; Water Quality Status; Way Kuala River

Nile tilapia (Oreochromis niloticus) is one of the leading aquaculture commodities in Indonesia, valued for its high economic potential and growing market demand. The success of tilapia farming is highly influenced by optimal water quality, particularly the level of dissolved oxygen (DO), which plays a crucial role in supporting the metabolic and physiological processes of the fish. One commonly used technology to maintain DO levels is the diffusion aerator system, whose efficiency is strongly affected by the design and diameter of the diffuser. This study aimed to analyze the effect of diffuser diameter variation on water quality and tilapia growth performance, and to determine the most effective diameter for maintaining optimal rearing conditions. The experiment was conducted over 45 days using a completely randomized design (CRD) consisting of six treatments and three replications: (A) stone aerator (control), and custom-made diffusers constructed from used tires with diameters of (B) 1 inch, (C) 2 inches, (D) 3 inches, (E) 4 inches, and (F) 5 inches. Observed water quality parameters included temperature, pH, DO, ammonia, nitrite, and alkalinity. Growth performance indicators measured included specific growth rate (SGR), daily feed intake, feed conversion ratio (FCR), and survival rate. The results indicated that all treatments-maintained water quality within optimal ranges for tilapia culture. However, no significant differences (p > 0.05) were observed in growth performance across treatments. These findings suggest that tire-based diffusers can serve as effective, economical, and environmentally friendly alternatives to conventional aeration systems in tilapia aquaculture. Keywords: Aeration; Aquaculture; Assembled Diffuser; Fish Growth; Nile Tilapia; Water Quality