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Effect of reproductive maturity on oilyYield, proximate composition, and fatty acid profile of marine fish roe

2026-08-05T06:29:20Z

Title: Effect of reproductive maturity on oilyYield, proximate composition, and fatty acid profile of marine fish roe Authors: Shanuke, D. S.; Coswatte, A. C. W. W. M. C. L. K.; Jayani Chethana, Minoli Tissera; Jayamanne, S. C. Abstract: This study evaluated the effects of reproductive maturity on proximate composition, oil yield, and fatty acid profile of roe oil extracted from Thunnus albacares, Katsuwonus pelamis, Canthidermis maculata, and Lepidocybium flavobrunneum. Roe at different maturity stages (immature, maturing, and mature) were analyzed in triplicate. Proximate analysis was conducted to determine the lipid and other nutrient content. Roe oil was extracted using five techniques, namely heat hydrolysis, salt extraction, natural enzymatic hydrolysis, mechanical pressing, and solvent extraction. Fatty acid composition was analyzed using gas chromatography–mass spectrometry. The highest lipid content (p < 0.05) was observed in mature roe of all species compared to immature and maturing stages. Solvent extraction using isopropanol: hexane (2:1) yielded the highest (p < 0.05) roe oil. The highest oil recovery (p < 0.05) was obtained from mature T. albacares (3.52 ± 0.17%). Polyunsaturated fatty acids (PUFAs) predominated in roe oil with the highest levels detected in immature roe. The highest PUFA content (38.29 ± 1.04%) was observed in immature T. albacares roe oil. In contrast, L. flavobrunneum exhibited a significantly higher proportion of monounsaturated fatty acids, exceeding 45%. Results demonstrated that reproductive maturity and extraction techniques significantly influenced roe oil yield and fatty acid composition.

Molecular and histopathological detection of vibrio harveyi associated with mortality in Asian sea bass cultured in Sri Lanka

2026-07-13T06:40:27Z

Title: Molecular and histopathological detection of vibrio harveyi associated with mortality in Asian sea bass cultured in Sri Lanka Authors: Velichor, Sakajamary; Mohamed Fouzi, Mohamed Naleem; Jagoda, Samanthika; Jinadasa, Rasika; Musthafa, Muneeb Mohamed; Thassim Marikar, Faiz Mohideen Mohamed Abstract: Asian sea bass (Lates calcarifer), commonly known as barramundi, is an economically important food fish inhabiting coastal and brackish waters. In Sri Lanka, demand for commercial and recreational fishing has increased due to its mild flavor and culinary versatility. However, disease outbreaks pose significant challenges to aquaculture production, particularly in cage culture systems. This study investigated the causative agent of mass mortality events in Asian sea bass farms in Trincomalee, Sri Lanka. Fish exhibiting clinical signs, including skin ulcers, fin rot, exophthalmia, and lethargy, were collected for examination. Samples from the kidney, liver, and spleen were cultured on Tryptic Soy Agar (TSA) and Thiosulfate Citrate Bile Salts Sucrose (TCBS) agar at 37 °C for 24-48 hr. Isolates produced small to medium, round, convex colonies on TSA and green colonies on TCBS. Biochemical characterization revealed Gram-negative, oxidasepositive, catalase-positive, motile rods that fermented glucose without gas production. Molecular identification using 16S rRNA polymerase chain reaction confirmed the pathogen as Vibrio harveyi with 99.44% similarity to strain CP014038.2. The sequence was deposited in GenBank (accession number OR351233). Histopathological examination revealed tubular injury, necrotic epithelial cells, and macrophage-lymphocyte infiltration in liver and kidney tissues. This study confirms that Vibrio harveyi is strongly associated with Vibriosis, causing mass mortality in Asian sea bass cage culture in Trincomalee. These findings provide essential baseline data for developing effective disease prevention and control strategies in Sri Lankan aquaculture systems.

Laying hen welfare in intensive farming system in Sri Lanka: a five freedoms approach

2026-07-13T06:39:51Z

Title: Laying hen welfare in intensive farming system in Sri Lanka: a five freedoms approach Authors: Athukoralaa, A. I. C. D.; Nikzaada, R. M.; Niwanthakab, R. M. D.; Musthafaa, Muneeb M.; Marikar, Faiz M.M.T. Abstract: Animal welfare refers to the state of an animal's physical and mental health as well as its well-being, humane treatment, and appropriate care. The purpose of this study was to evaluate the welfare of a flock of laying hens on an intensive farm in Kundasale, Sri Lanka's mid-country. The Five Freedoms and welfare indicators, including as behaviour, environmental circumstances, and production statistics, were used to evaluate the overall welfare of the farm. The Five Freedoms and behaviours like eating, drinking, relaxing, strolling, dust bathing, foraging, excretion, and flapping were among the welfare indicators that exhibited notable variations. The Kundasale farm in Sri Lanka was categorised as a "Normal farm" with an overall wellbeing score of 44.73%, which is between 40 and 60%. In terms of meeting the needs of the intensive broiler breeder farm, the results of this assessment contributed to enhancing flock welfare standards and improvements in the poultry farming practices of this farm

Assessment of locally available substrates for enhancing sustainable moina macrocopa production

2026-07-13T06:39:20Z

Title: Assessment of locally available substrates for enhancing sustainable moina macrocopa production Authors: Kumari, S.; Fouzi, M. N. M.; Musthafa, M. M.; Thaiuba, A.; Marikar, F. M. M. T Abstract: Artemia is commonly used to feed fish larvae, but its high cost, specific hatching conditions, and limited local availability make it less accessible in developing countries. Moina macrocopa, a nutritionally rich and widely distributed zooplankton, offers a promising low-cost alternative, though knowledge on its large-scale production and feeding techniques remains limited. The present study was designed to evaluate the effect of different animal manures and food waste as substrates in the mass culture of Moina macrocopa, to identify the most effective and sustainable method for maximizing its production in terms of both quality and quantity. To assess the efficacy of various locally accessible substrates for the sustainable mass culture of Moina macrocopa, three laboratory experiments were carried out. Four treatments soy milk plus poultry manure, rice bran plus fish meal, cow dung plus yeast, and cow dung alone were applied to a pure culture of M. macrocopa that was fed with Chlorella sp. Moina population counts were taken every day for seven days throughout each experiment, which was conducted under controlled circumstances with constant aeration. The combination of yeast and cow dung produced the greatest average population (228.16 individuals per 600 ml) among the treatments, suggesting that this substrate is the most efficient and sustainable choice for producing Moina macrocopa on a wide scale.