Asian Journal of Fisheries and Aquatic Research
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Isolation and Identification of Bacteria Associated with Commercially Hawked Ready-To-Eat Fried Fish Sold in Jos Metropolis
No full textAims: This study aimed to isolate and identify bacteria associated with commercially hawked ready-to-eat fried fish sold in Jos metropolis in Plateau State, Nigeria.
Methodology: A total of 20 fried fish Samples were obtained through random sampling of fish from vendors and collected in a sterile polyethylene bag and packaged in a sterile foil paper and then it was transported to the laboratory. The media used such as Nutrient agar (NA), Blood agar and MacConkey agar were prepared following the manufacturer’s specification. For microbial isolation, 5mL of each sample was dissolved into 50mL sterile water inside different beakers. Then, 1mL of the dissolved sample was aseptically transferred into 9mL sterile distilled water and serially diluted up to the appropriate dilutions (i.e., 10-1 to 10-6 dilutions). From the dilutions 10-3, 0.1mL was aseptically transferred into sterile Petri dishes and their spread plated with already sterilized molten media. The Petri plates were incubated at 37oC for 24hrs for bacteria. After incubation, the cultural characteristics, colonial morphology were observed on the plates. Pure colonies were obtained by sub-culturing on a fresh growth media and stored at a refrigeration temperature of 0-4oC. Microbial isolates were identified by biochemical and phenotypic characterization.
Results: A total of 35 bacteria species were isolated from 20 commercially hawked ready-to-eat fried fish samples sold within Jos metropolis of Plateau State, Nigeria. The laboratory analysis revealed a significant microbial contamination. Pathogenic bacteria Isolated includes: Staphylococcus aureus, Klebsiella aerogenes, Escherichia coli, Salmonella spp., Pseudomonas aeruginosa and streptococcus spp., while non-pathogenic or opportunistic isolates includes: Bacillus coagulans, Bacillus circulans, Citrobacter spp., Coagulase-negative staphylococci and Rahnella inusitata. Total bacterial counts (TBC) reached alarming levels, such as 3.6 x 10^6 CFU/g in sample ABTe. Notably, Klebsiella aerogenes was the most frequently isolated organism, accounting for 28.57% of all isolates, indicating widespread contamination in the local aquatic environment.
Conclusion: The presence of pathogenic bacteria underscores the need for improved food safety measures among vendors. Comparative analysis with prior studies shows consistent contamination levels, reinforcing the necessity for stringent hygiene practices
Seaweed Planlet Growth Kappaphycus alvarezii with Different Lengths of Maintenance Time
No full textSeaweed Kappaphycus alvarezii has a high economic value. This seaweed is included in the class Rhodophyceae or red algae which is known for its diverse nutritional content, high vitamin content, protective pigments, and sufficient mineral content, so that this seaweed is widely used in various industries, such as the food industry, health sector, and cosmetics industry. The problem that cultivators often face is limited seeds, so tissue culture seeds are needed. Different seaweed harvest periods will affect the quality produced. From this statement there has been no related research regarding the different lengths of maintenance for seaweed plantlets resulting from tissue culture, especially in Gerupuk Bay. Therefore, it is important to carry out research regarding different lengths of maintenance, with the aim of finding out the optimal harvesting period for cultivators. The method used in this research was an experimental method with a completely randomized design. This treatment was carried out with 4 treatments and 3 repetitions, namely P1: 30 days, P2: 35 days, P3: 40 days and P4: 45 days. The four treatments were repeated 3 times to obtain 12 experimental units. The initial seed weight used in each treatment was 10 grams. The water quality parameter values obtained during the research are still considered optimal. The results of the research carried out can be concluded that the harvest age for seaweed Kappaphycus alvarezii have a real influence on weight growth, specific growth in seaweed. The best absolute growth was obtained in the P4 treatment with a 45 day harvest with a weight of 388 grams, as well as the best specific growth rate in the P4 treatment of 5.91%
Impact of Artisanal Fishing Gears on the Fisheries Stock of Lake Geriyo, Adamawa State, Nigeria
No full textThis study was carried out to ascertain the Impact of artisanal fishing gears on the fisheries stock of Lake Geriyo, Adamawa State, Nigeria. The study was conducted monthly for four months from August to November, 2023. In the conduct of this study, both primary and secondary methods of data collection were used. A total of Eighty (80) respondents were sampled with structured interview and questionnaire. Data obtained were analysed with descriptive and inferential statistics. There were seven different fishing gears employed by fishermen to exploit fish in Lake Geriyo. Most prominent of the gears are the gill net and Cast net. Fish are abundant during the rainy season but catch quantities and sizes are decreasing. There were some missing fish species in Lake Geriyo. Most fishermen were not aware of any law that forbids catching of small-sized fish. Among various reasons for catching smallsized fish include: abundance and monetary gains. The study also revealed that thirteen (13) fish species from seven (7) families were caught by the seven artisanal fishing gears in the Lake. The study revealed the obvious neglect of the artisanal fisherfolks with regards to provision of infrastructural facilities despite the enormous contribution they give to the domestic fish output. Therefore, fishermen should be encouraged to fish responsibly for the sustainability of Lake Geriyo fisheries. Addressing these issues will require a combination of stricter fishing regulations, better enforcement mechanisms, and the promotion of selective fishing gear to prevent the depletion of fish populations
Evaluation of Glucosamine Hydrochloride from Biowaste of Macrobrachium rosenbergii and Penaeus monodon in Different Ponds of Andhra Pradesh, India
No full textA variety of goods made from the skeletons of crustaceans have both biomedical and pharmacological abilities. As an amino monosaccharide that serves as a substrate for the synthesis of aggrecan and proteoglycans, glucosamine has therapeutic potential for osteoarthritis. The goal of the current work is to produce glucosamine hydrochloride (Glu-HCl) by acid hydrolysis from a variety of crustacean shells, specifically Macrobrachium rosenbergii and Penaeus monodon (tiger shrimp), and then quantify the result using reversed phase high performance liquid chromatography (RP-HPLC). The fiber found in crab, lobster, shrimp, and prawns is called chitin. Chitosan, a naturally occurring biopolymer, was created by deacetylating chitin, one of the main structural components that make up the exoskeleton of crustaceans. Chitosan is a linear polymer of a (1–4)-linked 2-amino 2-deoxy b-D glucopyranose. Shell trash is produced in large quantities by the aqua industry and is typically dumped, causing significant environmental nuisance. Glucosamine hydrochloride, chitin, and chitosan can all be obtained commercially from such waste. In this study, the yield % of the tiger shrimp (Penaeus monodon) and freshwater prawn (Macrobrachium rosenbergii) is being assessed. In comparison to P. monodon, M. rosenbergii was a superior producer. The recycling of crustacean waste into a product with added value is also covered in this study
Analysis of Coral Reef Community Structure and Coral Cover in Tanjung Seloka Village, Pulau Laut Selatan District, Kotabaru District, South Kalimantan Province, Indonesia
No full textInvolvement of local communities in conservation efforts is one of the keys to the success of preserving marine biological resources. This study aims to evaluate the structure of coral reef communities and the extent of coral cover in Tanjung Seloka Village, Pulau Laut Selatan District, Kotabaru Regency, South Kalimantan Province. The research was conducted in the coastal waters of Tanjung Seloka Village, examining bioecological parameters such as live coral cover and coral growth forms, physical parameters including temperature (°C), water clarity (m), and current velocity (m/s), as well as chemical parameters such as salinity (‰), pH, and dissolved oxygen (DO). The Line Intercept Transect (LIT) method was employed to gather coral reef data. The findings revealed the presence of only two Acropora coral growth forms. The percentage of live coral cover ranged from 26.76% at Station 3 to 52.76% at Station 1. Coral reef conditions were classified between moderate and good. Most water quality parameters, including temperature, current speed, pH, and DO, remained within acceptable environmental standards. However, water clarity was below, and salinity was above, the quality thresholds set by the Minister of Environment Decree No. 51 of 2004
Dimensional Analysis of Cantrang Fishing Gear and its Implications for the Ecology and Biology of Fish in the Ancam River Estuary, North Kalimantan, Indonesia
No full textThe cantrang fishing gear is a type of fishing gear that is operated on the bottom of the waters by pulling it so that it is feared to have implications for damage to the ecosystem and biology of aquatic resources. This study aims to analyze the dimensions of the cantrang fishing gear based on Indonesian national standards (SNI) 01-7236-2006 and its implications for the ecology and biology of aquatic resources. This research is classified as a qualitative research type and was conducted using survey and interview methods. The research was conducted from March to May 2025 on the fishing gear used by fishermen in the Ancam River estuary, North Kalimantan. The results of the study showed that the longitudinal comparison of the parts of the cantrang fishing gear was in accordance, smaller and larger than SNI, in the transverse section all were smaller than SNI, the comparison of the number of grids on the cantrang section only the bag section was in suitable while the other parts were smaller, the material was all in suitable, while the mesh size was only the bag section that was in accordance while the others were all smaller. The dimensions of the cantrang fishing gear that did not comply with SNI had implications for damage to the basic aquatic ecosystem, disruption of the food chain and web, decreased catches, catching aquatic resources that had not reached a suitable size for catching. The dimensions of the cantrang fishing gear had differences in several parts so that they had an impact on the ecosystem and biology of aquatic resources
Effectiveness of Soaking Time and Bait Type on Dragon Trap Catch Results in Semarang Waters
No full textAims: The problem addressed in this research is the lack of empirical data on the optimal immersing duration and bait type to maximize the efficiency of dragon trap fishing for banana prawns (Penaeus merguiensis) in the coastal waters of Semarang. To analyze the effect of immersing duration and bait type on the catch of Banana Prawn (Penaeus merguiensis) in the waters of Semarang
Study Design: Experimental fishing.
Place and Duration of Study: This research was conducted in November 2024 at Tambak Lorok, Semarang City, Central Java, Indonesia.
Methodology: The method used in this study was experimental fishing, involving two variables: immersing duration and bait type, with seven repetitions. The immersing durations were set at 12 hours and 24 hours, and the bait type used were discarded catch, chicken intestines, and green mussel shells.
Results: The catch composition of the dragon trap includes banana prawn (Penaeus merguiensis), tiger shrimp (Penaeus monodon), dory snapper (Lutjanus fulviflamma), green mud crab (Scylla paramamosain), mangrove stone crab (Myomenippe hardwickii), barracuda (Sphyraena barracuda), and orange-spotted grouper (Epinephelus coioides). The highest average catch was obtained with a soaking time of 6 hours using discarded catch as bait, yielding a mean catch of 2.8 kg per trap. This was followed by the 8-hour soaking duration with discarded catch, which resulted in a slightly lower average catch of 2.5 kg. The 4-hour soaking time consistently produced the lowest yields across all bait types, with an average of 1.2 kg per trap. The Mann-Whitney test results showed an Asymp. Sig value of 0,018 (<0,05) for immersing duration, indicating a significant difference. Meanwhile, the Kruskal-Wallis test fir bait type resulted in a Asymp. Sig value of 0,173 (>0,05), indicating No. significant effect. The interaction between immersing duration and bait type using the Friedman test showed a significant effect with a value of ,0,000 (<0,05).
Conclusion: The study demonstrates that a 12-hour immersion period using discarded catch as bait is the most effective combination for maximizing banana prawn catch in dragon trap fishing operations, with immersion duration having a significant impact on catch efficiency
Effects of Water Lettuce Pistia stratiotes Substitution on Growth and Health of Nile tilapia (Oreochromis niloticus)
No full textThis study aimed to assess the effects of substituting of Pistia stratiotes diets for soybean at 10 % (S10), 20 % (S20) and 30 % (S30) levels, and a control (S0) on Oreochromis niloticus. Three treatments and a control, each with triplicates, were used, with an initial weight and length of the fish being 15.5 g and 9.8 cm, respectively. A-90 day feeding trial was conducted. Proximate composition of the formulated isoproteic diets (30 % crude protein) was determined in the laboratory, while the fish were fed twice daily at 9 am and 5 pm. Weight and length were measured every two weeks, and at the end of the feeding trial, blood samples were collected to determine haematological and biochemical indices using standard analytical methods. The results showed that crude protein and fibre showed no significant difference except for S0 which varied from others in crude fibre (6.73±0.34). S0 recorded the best final weight, weight gain and protein intake, followed by S10 with significant differences. S30 recorded the highest red blood cells (6.12±0.41) and packed cell volume (40.0±3.20), while S10 (11.57±0.41) had the highest white blood cell count, AST (65.01±4.90), and total protein (68.10±2.30). The overall results revealed that 10% substitution of Pistia stratiotes for soybean, promoted growth and feed utilisation comparable to the conventional diets. However, the elevated values of WBC and AST in fish fed with Pistia stratiotes diets suggest potential threats to immune system and liver health of the fish
Evaluation of Farmers Knowledge, Perception and Attitudes on Fish Production in Lesotho
No full textAims: This study aims to explore the multifaceted dimensions of fish farming by identifying its impacts on the economic and social status of farmers, investigating their awareness of general management practices in fish production, and determining the underlying rationale, opportunities, and challenges they encounter. Through this comprehensive approach, the research seeks to provide a deeper understanding of how fish farming influences livelihoods, the extent of farmers’ knowledge in sustainable practices, and the factors that shape their engagement in aquaculture.
Study Design: The study employed a descriptive and exploratory design and a combination of snow ball sampling technique. Fish farmers were interviewed on awareness on general management practices, opportunities and challenges and the impacts of fish farming on economic and social status.
Place and Duration of Study: The study was carried out in Maseru, which is the lowest geographical point in the country, resting at approximately 1,600 meters above sea level. The district experiences a temperate climate, with average temperatures ranging from 20.4 °C in summer to 6.6 °C in winter. Annual precipitation averages around 896 mm, with monthly rainfall of approximately 57.6 mm and about 88 days per year receiving more than 0.1 mm of rainfall (Lesotho Meteorological Services, 2013). The study was carried out across two divisions of Maseru: urban and rural. The urban division included the villages of Moshoeshoe II, Seoli, Thamae, and Ts’enola. The rural division comprised Roma, Mazenod, Moruthoane, and St Michales between August 2024 and August 2025.
Methodology: Data obtained from each respondent was entered directly into Statistical Package for Social Sciences (SPSS) analysis. Cross tabulations were used to calculate the percentages while Chi-Square test was used to test P-value.
Results: There was no significant association (P ≤ 0.05) between farmers’ demographics in all the investigated regions. All the investigated parameters under the impacts of fish farming on social and economic status of farmers revealed no meaningful linkage (P ≤ 0.05) when significance was examined. Variables under both awareness of fish farmers on management practices and opportunities and challenges showed no significant association (P ≤ 0.05).
Conclusion: Fish farming offers higher and more stable income than other agricultural activities, with growing participation from women and youth (83%), enhancing gender equality and employment. However, 66.7% of farmers in Lesotho lack awareness of key management practices like water quality checks and disease control. Despite contributing to food and nutrition security (50%), high input costs especially for feeds and nets remain a major challenge. Educating farmers is essential to improve production and sustainability
A Comprehensive Review of Morphometric and Meristic Variations in Freshwater Fishes: Trends, Environmental Drivers and Taxonomic Implications
No full textMorphometric and meristic traits offer powerful, cost-effective tools for analysing phenotypic variation, stock structure, and environmental adaptation in freshwater fishes. This review synthesizes findings from more than thirty studies published between 2012 and 2024, covering diverse taxa across Asia, Africa, and the Middle East. The literature reveals strong habitat-driven morphological plasticity, particularly in riverine species exposed to hydrodynamic forces, ecological gradients, and climatic variability. Morphometric traits, which respond rapidly to ecological pressures, consistently differentiated populations of Channa striata, Wallago attu, Schizothorax spp., Clupisoma garua, and several others. Meristic traits, although more genetically stable, also reflected population-level divergence under varied developmental and environmental conditions. Integrating these patterns, the review highlights the importance of morphology for taxonomy, species discovery, biodiversity monitoring, and sustainable fisheries management. Despite methodological challenges—including inconsistent measurement protocols and limited geographic coverage—advances in geometric morphometrics, molecular barcoding, and multivariate analytics have strengthened morphological research. The review emphasizes the need for standardized methodologies and integrated approaches to better understand phenotypic diversity and ensure the conservation of freshwater fish resources in rapidly changing ecosystems