Jurnal Ilmiah Samudra Akuatika

Diversity and Distribution of Pathogenic Bacteria Infecting Common Carp (Cyprinus carpio) in Center of Aquaculture Areas at Pabuaran, Subang, West Java

2026-06-17T05:19:44+00:00

The aquaculture sector frequently encounters disease problems, both infectious and non-infectious. Infectious diseases in fish can be caused by viruses, bacteria, parasites, and fungi, all of which can reduce productivity and threaten the sustainability of aquaculture operations. This study aimed to determine the distribution and types of pathogenic bacteria infecting common carp (Cyprinus carpio) and to analyze the prevalence of these pathogens in common carp farming centers located in Pabuaran and Salam Jaya Villages, Pabuaran District, Subang Regency, West Java. Sampling was conducted using a purposive sampling technique at four observation stations. Bacterial isolation was conducted from kidney and lesion tissues using Tryptic Soy Agar (TSA), followed by identification based on colony morphology, Gram reaction, and biochemical tests including catalase, oxidase, TSIA, MIO, O/F, and glucose fermentation tests. The results showed that in Pabuaran Village, Station 1 contained three types of pathogenic bacteria: Aeromonas sp. (87%), Pseudomonas sp. (6.7%), and Enterobacter sp. (6.7%), while Station 2 contained two types: Aeromonas sp. (93%) and Pseudomonas sp. (7%). In Salam Jaya Village, Station 1 contained Aeromonas sp. (87%) and Pseudomonas sp. (13%), while Station 2 contained Aeromonas sp. (87%) and Enterobacter sp. (13%). Overall, Aeromonas sp. was identified as the dominant pathogenic bacterium infecting common carp in both study locations.

Mineral Composition (Ca, Mg, K, and Na) in the Culture Water of Pacific White Shrimp (Litopenaeus vannamei) in Purworejo Village, Pasir Sakti District, East Lampung

2026-06-17T05:19:45+00:00

Minerals are essential components of shrimp culture water, playing important roles in osmoregulation, growth, and survival of Pacific white shrimp (Litopenaeus vannamei). This study aimed to analyze the mineral content of water used for L. vannamei culture in Purworejo Village, Pasir Sakti District, East Lampung Regency, Indonesia. The observed mineral parameters included calcium (Ca), magnesium (Mg), potassium (K), and sodium (Na). Water samples were collected from three shrimp ponds at 5, 20, and 35 days of culture (DOC) and analyzed using a descriptive approach. The results showed that Ca concentrations ranged from 186.7 to 266.7 mg/L, Mg from 307.4 to 396.4 mg/L, K from 43.3 to 70.8 mg/L, and Na from 1,767.5 to 4,308.6 mg/L. Compared with the recommended ranges for optimal L. vannamei culture, most mineral concentrations were relatively low. These conditions may affect water quality and potentially limit shrimp growth performance. Therefore, mineral supplementation and appropriate water quality management are recommended to improve culture conditions and support sustainable shrimp production.

Proximate Analysis of Papain Enzyme-Supplemented Feed and Its Effects on Protein Efficiency Ratio and Feed Utilization Efficiency in Freshwater Crayfish (Cherax quadricarinatus)

2026-06-17T05:19:46+00:00

Papain is a proteolytic enzyme extracted from unripe papaya (Carica papaya) fruit and functions as a catalyst in the hydrolysis of proteins into simpler compounds. In aquaculture production, feed costs account for approximately 60–70% of total production expenses, highlighting the need for high-quality feed with enhanced utilization efficiency. This study aimed to analyze the proximate composition of feed supplemented with papain enzyme and to evaluate its effects on feed utilization efficiency (FUE) and protein efficiency ratio (PER) in freshwater crayfish (Cherax quadricarinatus). The feeding trial was conducted at UKM Kasih Karunia, Bube Village, Suwawa District, Bone Bolango Regency, Gorontalo, Indonesia. The study employed an experimental research design consisting of two treatments and three replications. The results showed that feed supplemented with 3.5% papain enzyme contained 41.10% crude protein, 20.35% moisture content, 2.71% crude fat, 6.35% crude fiber, 36.00% nitrogen-free extract (NFE), and 13.84% ash content. Furthermore, the feed utilization efficiency of the papain-supplemented diet reached 49.47%, which was considerably higher than that of the control diet without papain supplementation, which recorded an FUE value of 16.32%. These findings suggest that the inclusion of 3.5% papain enzyme in feed improves its nutritional quality and significantly enhances feed utilization efficiency in freshwater crayfish (C. quadricarinatus), thereby demonstrating its potential as a feed additive for aquaculture applications.

Clustering of Blue Swimming Crab Catch Productivity Based on Fishermen's Age Using the K-Means Algorithm in Pantai Lunci District

2026-07-06T11:08:23+00:00

The ability to achieve optimal blue swimming crab catches is influenced by the age of the fishermen. Fishermen of productive age generally exhibit better working capabilities, supported by more optimal physical conditions and greater experience in conducting crab-catching activities. Therefore, this study aims to cluster blue swimming crab catch volumes based on the fishermen's age. This research utilizes the K-Means Algorithm method. The data used as samples for crab catch production were obtained through interviews and questionnaires with 64 fishermen in the Pantai Lunci District. The results revealed three distinct clusters of monthly crab catch volumes. Cluster one consists of catch volumes ranging from 75–150 kg/month by fishermen aged 26–65 years. Cluster two includes catch volumes ranging from 168–300 kg/month by fishermen within the age range of 28–53 years. Cluster three represents a catch volume of 500 kg/month by fishermen within the age range of 33–42 years. This 3-group clustering model provides an optimal value with a silhouette score of 0.846.

Physiological Responses and Survival of Prospective Nile Tilapia (Oreochromis niloticus) Broodstock Anesthetized with Clove Oil (Syzygium aromaticum) at Different Stocking Densities During Simulated Transportation

2026-07-13T10:59:20+00:00

Nile tilapia (Oreochromis niloticus) is one of the most economically important freshwater aquaculture species and is highly susceptible to stress during transportation, making the use of anesthetics essential to improve survival. This study aimed to evaluate the physiological responses and survival of prospective Nile tilapia broodstock at different stocking densities following clove oil (Syzygium aromaticum) anesthesia during simulated transportation. The experiment employed a completely randomized design (CRD) consisting of four stocking density treatments, each with three replicates. The observed parameters included induction time, recovery time, oxygen consumption rate, survival rate, and water quality. The results showed that the longest induction time was recorded in treatment P4 (20 fish), averaging 24.16 minutes, whereas the shortest induction time occurred in treatment P1 (5 fish), averaging 21.48 minutes. Numerically, induction time tended to increase with increasing stocking density. Stocking density significantly influenced the behavioral responses of prospective Nile tilapia broodstock during simulated transportation under clove oil anesthesia. The highest post-transport survival rate was observed in treatment P3 (15 fish), reaching 88.83%, while the lowest survival rate was recorded in treatment P4 (20 fish), at 61.67%.