Browsing by Author "Athula, J.A."
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Item Comparative Study on Growth Performance and Profitability of Shrimp Farming Industry in Sri Lanka: Native Penaeus monodon vs. Imported Specific Pathogen Free(Uva Wellassa University of Sri Lanka, 2020) Priyadarshana, S.D.A.M.; Athula, J.A.; Ranathunga, R.M.N.P.K.; Lakmal, J.A.S.; Adikari, A.M.L.W.Until 2018, Penaeus monodon was the main commercial-scale cultured shrimp species in Sri Lanka and the seed production industry depended on wild-caught native broodstock. Due to the high prevalence of White Spot Disease among the wild-collected brood shrimps, the farming industry has been affected by post larvae shortage and disease outbreaks. As a solution, National Aquaculture Development Authority has decided in 2016 to introduce Specific Pathogen Free (SPF) broodstock to the industry imported from Thailand and they are planning to encourage the SPF shrimp farming in the country. Therefore, this study was focused to compare the growth performance and profitability of farming these two varieties. During the period of 21st March 2019 to 28th February 2020, 14 ponds for each variety were selected from the Ambakandawila area in Puttalam District for the study. Data collection was initiated after the 8th week of the stocking and continued up to the harvest. Specific Growth Rate (SGR), Survival Rate (SR), Average Daily Gain (ADG) of the body weight, Feed Conversion Ratio (FCR), total cost, revenue, and net profit were calculated. SGR was recorded as 2.51 ± 0.1 & 2.13 ± 0.06 and ADG of the body weight was recorded as 0.31 ± 0.02 & 0.23 ± 0.01 g day-1 for SPF and native shrimp varieties respectively. SR was recorded as 70.1 ± 3.4% & 69.9 ± 3.2% and FCR was recorded as 1.51 ± 0.04 and 1.54 ± 0.07 for SPF and native shrimp varieties respectively. It recorded 1,482,311.62 ± 50,687.49 and 1,087,716.21 ± 72,449.54 LKR acre-1 as the total cost of the farming of SPF and native shrimp varieties respectively. Total revenue was recorded as 1,783,733 ± 102,197 and 1,535,122 ± 162,199 LKR acre-1 and estimated net profit was calculated as 301,421 ± 105,412 and 447,406 ± 101,576 LKR acre-1 for SPF and native shrimp culture systems respectively. Although the SGR, SR, ADG, FCR are better in SPF shrimps than native shrimps, profitability mainly depends on the total cost. Keywords: SPF Penaeus monodon, Shrimp farming, Growth performance, ProfitabilityItem Development of Quality Assessment Guideline for Litopenaeus Vannamei (Whiteleg Shrimp) Post Larvae(Uva Wellassa University of Sri Lanka, 2020) Premarathna, N.M.C.N.; Athula, J.A.; Soyza, W.A.D.; Lakmal, J.A.S.Penaeus monodon is the main brackish water aquaculture species in Sri Lanka which targets the production for the export market. Litopenaeus vannamei (Penaeus vannamei) was introduced in 2018 as a new species expecting a rapid increase in production in the country. As a management strategy implemented by the National Aquaculture Development Authority (NAQDA), the assessment of post larvae quality is a compulsory requirement to obtain a better harvest via better growth without disease infections. Quality assessment of the P. monodon is based on 10 criteria and a minimum of 80% marks are required to get the approval for stocking. Up to now, the same assessment method has been used for P. vannamei, and due to some morphological and anatomical deviations; it did not totally comply with the new species. Hence, this study aimed to develop a post larvae quality assessment guideline for Litopenaeus vannamei with a score allocation procedure for each quality assessment criterion. The characteristics of different post-larvae stages (PL 1 - PL 30) from three different culture cycles of Litopenaeus vannamei were evaluated under each criterion and performed microscopically and morphologically. The microscopic observations were Monodon baculoviruses and Baculovirus penaeid, condition of hepatopancreas and gut content, necrosis and deformities, epibiont fouling, muscle opaqueness, and gut to muscle ratio of post larvae. The average body length, rostral spines, and size variation of each PL stage were the morphological observations measured to apply as standard values. The obtained values for post larvae of P. vannamei differed from the values of P. monodon. This study reveals the incompatibility of using the same assessment method for both shrimp species. Revision of marks allocation procedure, validation of the quality assessment method, and introduction as a new guideline will contribute to the future development of the Litopenaeus vannamei farming industry in Sri Lanka. Keywords: Litopenaeus vannamei, Post larvae quality, Quality assessment guideline, Shrimp farmingItem Effect of Diets Incorporated with Dried and Autolyzed Shrimp Waste on Growth Performance of Goldfish (Carassius auratus)(Uva Wellassa University of Sri Lanka, 2016) Rathnayake, R.M.C.P.; Liyanage, N.P.P.; Athula, J.A.; Guruge, K.P.G.K.P.; Senaarachchi, W.A.R.K.The shrimp processing industry turns out tons of head, tail and shell waste every year and this is a rich source of protein that could be used to prepare aquaculture feeds. The efficiency of different methods for extracting protein from shrimp waste were observed. This study has been designed to assess the possibility of partial replacement of fish meal with shrimp waste in diets formulated for goldfish. Known amount of shrimp waste samples were subjected to autolysis and subsequently subjected to oven drying and make fine powder. Crude protein, crude lipid, ash and moisture were estimated for both autolysed and powdered dried shrimp waste (purchased from Agri-Star Compost private limited). Two different diets were prepared by incorporating autolysed shrimp waste powder and dried shrimp waste powder as supplementary source of protein. Commercial feed that contains 42% protein was used as the control diet. Uniform sized glass tanks were stocked with twenty individuals with an initial mean weight of 0.13 f 0.00 g per tank. Fishes were hand-fed daily three times per day for 30 days with three diets. Wet weight of the fish were measured weekly. Feed Conversion Ratio (FCR), Specific Growth Rate (SGR), Protein Efficiency Ratio (PER) and Condition Factor (K) were calculated for each diet. The highest protein level (65.55%± 0.60) and lowest ash level was observed (11.35% ± 0.03) in autolysed shrimp waste. Significantly higher SGR, PER and survival rate (91.25% + 3.15) were observed in individuals fed with diet incorporated with autolysed shrimp waste while significantly low FCR was observed in the same (P<0.05). Condition Factor was not significantly changed among the test diets (P>0.05). The findings of this study indicate that autolysis is the best method to extract protein form shrimp waste. During the process of autolysing meat part was detached from the shell and extracted to the aqueous medium. This process will facilitate to collect comparatively pure source of protein with compared to the dried shrimp meal. Therefore, autolyzed shrimp waste powder that contains significantly higher protein percentage can effectively enhance the growth parameters while use as protein supplement in the diet of goldfish. Keywords: FCR, SGR, Fish feed, Fish nutrition, Ornamental fish.Item Efficiency of Manganese Removal by Eichhornia crassipes and Pistia stratiotes from Contaminanted Water(Uva Wellassa University of Sri Lanka, 2019-02) Jayawardhana, I.D.S.T.; Athula, J.A.; Thilakarathne, E.P.D.N.Metal pollution is a major problem of water sources used for drinking purposes. Among heavy metals, Manganese (Mn) is an essential trace element for the functioning of human, animal and plants but it leads to toxicity when it exceeds the standard level. Phytoremediation can be applied to remove heavy metals from aquatic environment. Floating aquatic macrophytes are used as an environmental friendly, efficient and cheap method. In presence study two aquatic plant species, Eichhornia crassipes (Water Hyacinth) and Pistia stratiotes (Water Lettuce) were used to determine the efficiency of removing Manganese. Bioassays using Water Hyacinth and Water Lettuce were carried out with de-ionized water contaminated by three concentration series (20, 40, 60 mg L-1) of Manganese (Π) for a period of 24 days. Three replicates were carried out for each series. Water samples were taken from each series at one day intervals and remaining manganese were analyzed using Atomic Absorption Spectrometry technique. Variations of pH and electrical conductivity of water were also measured as same interval by standard techniques. Data were statistically analyzed using SPSS16.0 package. Both Eichhornia crassipes and Pistia stratiotes showed the highest removal efficiency at the lowest concentration of Manganese (20 mg L-1). Average efficiency of manganese removal from water by Eichhornia crassipes and Pistia stratiotes were 67.61% and 80.04% respectively. Higher manganese removal efficiency was observed in Pistia stratiotes than Eichhornia crassipes. There was a significant difference (p<0.05) between absorbed manganese concentrations with the time in Eichhornia crassipes, but there was no significant difference (p>0.05) in Pistia stratiotes. The results of the study revealed that the both plants can be used to remove manganese from contaminated water. However, it is needed to conduct a pilot study for the water contaminated with manganese.Item Growth Performance of Black Tiger Shrimp (Penaeus inonodon) Based on Three Different Brood Stock Collecting Areas Handala, Beruwala and Mulathivu in Sri Lanka(Uva Wellassa University of Sri Lanka, 2018) Ekanayake, E.M.H.Y.; Athula, J.A.; Atapaththu, A.M.D.N.S.; Ranathunga, R.M.N.P.K.Seed production of shrimp aquaculture industry in Sri Lanka is totally depends on the wild captured brood stocks. Among the 17 recorded brood stock collecting areas; Handala, Beruwala and Mulativu areas are provided proportionally higher amounts of brood shrimps to the industry. This study was carried out to investigate the differences of the growth performances of the cultured shrimps in accordance to the collecting area of the brood stock to produce post larvae (PL). 15 days old PL pertaining to three different collecting areas including three replicates for each area were stocked in fiberglass tanks (6m2) with the stocking density of 266m-2. Water quality, feeding and other management practices were maintained almost equally in all culture tanks. Initial PL quality, initial & subsequent average total length and average body weight were measured weekly up to the end of the culture period of 45 days. Survival rates, instantaneous mortality and specific growth rates were calculated. Data were analyzed using one-way ANOVA (P<0.05) to determine significant differences of growth parameters. It was revealed that no significant difference (P>0.05) of the initial body length and weight of PL stocks collected from three different areas. Though, initial quality parameters of the PL according to the brood stock collection area were not different significantly, lowest PL quality was recorded as 83% from Mulativu area and both Handala and Beruwala were recorded as 94%. After the culture period, highest significant (P<0.05) average body weight (1.04±0.08g), average body length (36.811.23min), highest significant instantaneous mortality rate (5.33±0.66) and lowest survival rate (51.0±9.53) were recorded for the PL produced using brood stock collected from Mulathivu area. There was no significant difference (P >0.05) of the specific growth rate of the all cultured shrimps. Overall results indicated that, there was no significant difference between the PL producing from brood stocks collected in three different areas.Item Growth Performance of Panulirus ornatus (Spiny lobster) with Three Different Feeds in Indoor Culture in Jaffna, Sri Lanka(Uva Wellassa University of Sri Lanka, 2021) Jenitha, J.; Athula, J.A.; Nirooparaj, B.Indoor fattening practices of Panulirus ornatus (spiny lobsters) operated in Jaffna, Sri Lanka practicing with typical trash fish feeding. Effect of growth was evaluated with different feeds and water quality of P. ornatus culture and suggest a proper feed among the aquafarmers for P.ornatus due to unaware about feeds. Study entailed Completely Randomized Design with three different feeds (trash fish, crab meat, and clam flesh) and three replicates, 45 wild-caught P. ornatus of mean body weight 440.91 ± 29.11 g mean carapace length 8.00 ± 0.37 cm were stocked at the rate of two per m2, cultured for 11 weeks, fresh chopped flesh fed at optimum rate of 5% of body. Water quality including temperature, pH, salinity, Dissolved Oxygen, nitrate, nitrite and total ammonia and growth performance indicators of Average Daily Weight gain (ADW), Average Daily Length gain (ADL), Specific Growth Rate (SGR), Feed Conversion Ratio (FCR) and survival rate were examined and proximate analysis was done. P. ornatus had grown best on clams which containing highest crude protein 70.26 ± 13.26% lowest fat 0.60 ± 0.18%, indicating highest SGR as 0.19 ± 0.02% where trash fish and crab fed lobsters showed lowest SGR 0.16 ± 0.02% and 0.13 ± 0.04% with the crude protein, and fat levels of 18.13 ± 4.64%, 8.58 ± 1.09% and 10.66 ± 1.77%, 1.64 ± 0.22% respectively. Highest ADW was recorded from clam fed lobsters as 0.94 ± 0.11, 0.77 ± 0.11 and 0.58 ± 0.15 g day−1 for lobsters fed with trash fish and crabs respectively. Lowest FCR of 1.42 ± 0.05 showed with clam fed lobsters, crab and trash fish fed lobsters showed relatively high FCR indicating 2.76 ± 1.37, 1.63 ± 0.37 respectively. Growth significantly (P < 0.05) affected by water quality and maximum growth occurred at 29 ˗ 30°C temperature, 0.01 ˗ 0.02 mg Lˉ1 of Ammonia, 6.5 ˗ 6.9 mg Lˉ1 of the Dissolved Oxygen levels. Survival rate was similar as 100% in all treatments. Findings show that spiny lobsters grow well when fed clams high in protein and lowest fat indicating suitability in lobster farming industry. Keywords: Panulirus ornatus; SGR; Growth performanceItem Impact of Corona Virus Disease 2019 on Aquaculture and Inland Fisheries Sector with Special Reference to Trincomalee District in Sri Lanka(Uva Wellassa University of Sri Lanka, 2021) Lakshika, R.; Deyshappriya, N.P.R.; Athula, J.A.Corona virus disease (COVID-19) is an infectious disease spreaded rapidly across the borders creating pathetic health, economic and social impacts on each and every country in the world. In fact, aquaculture and inland fisheries is one of the industries which has been affected drastically. COVID-19 first time recorded in 2020 in Sri Lanka. This study aims to analyze the impacts of COVID-19 pandemic situation on aquaculture and inland fisheries sector in Trincomalee district focusing on the impacts on the inland capture fisheries and aquaculture community along with production dynamic during the period of 2019 and 2020. Mixed method and Purposive and stratified random sampling techniques have been employed as major methods of sampling during the data collection where a total of 155 individuals who are engaging in aquaculture and inland capture fisheries activities operated under the monitoring of National Aquaculture Development Authority in seven Divisional Secretariat divisions; Kuchchaveli, Morawewa, Trincomalee Town and Gravets, Thambalagamuwa, Kinniya, Muthur, Kanthale located in Trincomalee district. Pre- tested and structured questionnaire was used to collect the primary data from respondents while secondary data were collected from Trincomalee National Aquaculture Development Authority and mainly descriptive analysis was applied by using Microsoft excel to compare the situation before and during COVID-19 in order to accomplish the objectives of the study. The results indicated that Trincomalee district inland fisheries total production was 9% lower in 2020 with compare to the 2019. Apart from that, the study also confirmed the livelihood, education, health & food security, well-being, and happiness of aquaculture and inland fisheries community have been severely affected by the COVID-19, especially during lockdown period. Hence, this study emphasizes the necessity of providing livelihood assistance to such affected household in order to enhance their living standard and need to provide Advice with business continuity planning and Advice on how to prevent infections while maintaining business operations. Keywords: COVID-19; Aquaculture; Inland fisheries; Livelihood; Socio-economic impactsItem Study of Growth Performance of Oreochromis niloticus (Nile Tilapia) Fed by Formulated Diet Incorporated with Phytase Enzyme(Uva Wellassa University of Sri Lanka, 2018) Bandara, B.R.M.P.; Withanage, P.M.; Coswatte, A.C.W.W.M.C.L.K.; Athula, J.A.Fish is highly enriched with nutrients and serve as a valuable source of protein. Major constraints faced by inland aquaculture industry of Sri Lanka are higher feed cost and less growth performance of fish. Nile Tilapia (Oreochroinis niloticus) significantly contributes to the inland aquaculture due to its high adaptability to different environmental conditions and high growth rate. Phytase enzyme incorporated feed increases the release of phosphorus from plant meals and enhance the digestion in fish. Present study was focused to determine the effect of Phytase enzyme incorporated artificial feed on growth performance of Nile Tilapia. Two treatments, Treatment 1 artificial feed with Phytase enzyme and treatment 2 without phytase enzyme were conducted in fiberglass tanks (3.14 m3) with 3 replicates. Artificial feeds were formulated with 39% of protein and 0.2 g kg-1 of Phytase enzyme. Nile Tilapia fingerlings (mean weight 5g±1) were stocked with a stocking density of 5 fish per tank and reared for 10 weeks. They were fed three times per day at 5% of body weight. The live weight and total length of fish were measured within two weeks intervals. The weight gain of treatment 1 (17.25g±4.65) and treatment 2 (15.31g±4.10) were significantly different (p<0.05). Feed Conversion Ratio (FCR) for treatment 1 and 2 were 1.87±0.046 and 2.20+0.241 respectively with no significant difference. There was no significant difference of Specific Growth Rate (SGR) of fish between two treatments. Survival rate of both treatments were 100%. Since Treatment 1 revealed the highest weight gain, Phytase enzyme incorporated feed could be recommended to obtain the high growth performance of Nile tilapia in aquaculture industry.Item Study the Mitochondrial COI Gene Sequence Variation of Two Isolated Populations of Cephalopholis sonnerati (Valenciennes, 1828) in East and West Coasts of Sri Lanka(Uva Wellassa University of Sri Lanka, 2019) Jayawardane, I.D.S.S.; Aluwihare, Y.C.; Dalpathadu, K.R.; Haputhantri, H.S.S.K.; Athula, J.A.Cephalopholis sonnerati (Thambuwa) remained as one of the main reef fish species in the marine fishery sector in Sri Lanka. The major problem associated with the fish species is the huge population reduction in last few years due to the overexploitation. At present, this species has been protected under the fisheries law and this decision has been taken as a precautionary conservation and management measure. It is essential to conduct fish stock studies to assessment of sustainable fishing levels based on stocks. C. sonnerati in East and West coast may be from two different fish stocks due to the limited breeding between the populations. Due to the restriction of gene flow between two isolated populations, nucleotide level variation would provide a basic idea about population and stock structure. The study was conducted with the aim of identification of genetic variation at the mitochondrial cytochrome oxidase subunit I (COI) gene in two isolated populations. Fish samples were collected from east coast (Ampara and Batticaloa) and west coast (Chilaw). DNA was extracted by using CTAB method. PCR reaction was performed by using primers designed by COI gene sequences. PCR amplified products were sequenced and sequences were analyzed using BLASTn at NCBI and were aligned by using BioEdit and ClustalW sequence alignment tools. Even though the COI region is highly conserved region, single nucleotide polymorphism (SNP) was identified at 336th position (T/C) in both west and east coast C. sonnerati samples. To confirm the SNP in COI region more samples need to be used in the future studies. Due to the conserved nature of COI region very low nucleotide level difference was observed and all individuals shared similar sequences pattern. It can be confirmed that the two populations may still from the same stock. To confirm that it can be used microsatellite markers along with SNPs in future. This study provides a basic for future genetic stock studies.