Pub Date : 2021-12-31DOI: 10.33997/j.afs.2021.34.4.002
Mavindu Muthoka, E. Ogello, H. Ouma, K. Obiero
This study evaluated the effect of periphyton technology (PPT) on the growth performance and breeding schedule of Oreochromis niloticus (Linnaeus, 1758) juveniles. Six ponds, each measuring 81 m2 were used for the study. The ponds were applied with agricultural lime at a rate of 4 g.m-2, and fertilised using chicken manure to facilitate primary productivity. The PPT ponds were fitted with two-metre-long eucalyptus poles of 5 cm diameter placed at 50 cm intervals with the regular addition of molasses as a carbon source. Tilapia juveniles were stocked at a density of 3 fish.m-2 in all ponds and fed on a commercial diet of 20 % crude protein (CP) twice daily at 3 % body weight. Fish were sampled weekly for growth and survival data and bi-weekly for fecundity estimates. The PPT-ponds registered significantly higher survival rate (97.50 ± 0.35 %), mean weight (150.69 ± 0.99 g), specific growth rate (SGR) (2.75 ± 0.01), and feed conversion ratio (FCR) (1.29 ± 0.01), than the control ponds, which registered survival (91.15 ± 0.88 %), mean weight (99.23 ± 0.96 g), SGR (2.29 ± 0.00), and FCR (1.58 ± 0.01). There was significantly higher fecundity in the PPT-ponds (2.28 ± 0.09 g.fish-1) than control (1.74 ± 0.06 g.fish-1), with prolific spawning starting 4 weeks earlier in the control ponds than in the PPT-ponds. This study demonstrated the potential of PPT for enhancing tilapia growth while delaying prolific breeding behaviour. Further studies should explore PPT in replacing synthetic hormones for sex-reversal of tilapia fry in hatcheries.
{"title":"Periphyton Technology Enhances Growth Performance and Delays Prolific Breeding of Nile Tilapia, Oreochromis niloticus (Linnaeus, 1758), Juveniles","authors":"Mavindu Muthoka, E. Ogello, H. Ouma, K. Obiero","doi":"10.33997/j.afs.2021.34.4.002","DOIUrl":"https://doi.org/10.33997/j.afs.2021.34.4.002","url":null,"abstract":"This study evaluated the effect of periphyton technology (PPT) on the growth performance and breeding schedule of Oreochromis niloticus (Linnaeus, 1758) juveniles. Six ponds, each measuring 81 m2 were used for the study. The ponds were applied with agricultural lime at a rate of 4 g.m-2, and fertilised using chicken manure to facilitate primary productivity. The PPT ponds were fitted with two-metre-long eucalyptus poles of 5 cm diameter placed at 50 cm intervals with the regular addition of molasses as a carbon source. Tilapia juveniles were stocked at a density of 3 fish.m-2 in all ponds and fed on a commercial diet of 20 % crude protein (CP) twice daily at 3 % body weight. Fish were sampled weekly for growth and survival data and bi-weekly for fecundity estimates. The PPT-ponds registered significantly higher survival rate (97.50 ± 0.35 %), mean weight (150.69 ± 0.99 g), specific growth rate (SGR) (2.75 ± 0.01), and feed conversion ratio (FCR) (1.29 ± 0.01), than the control ponds, which registered survival (91.15 ± 0.88 %), mean weight (99.23 ± 0.96 g), SGR (2.29 ± 0.00), and FCR (1.58 ± 0.01). There was significantly higher fecundity in the PPT-ponds (2.28 ± 0.09 g.fish-1) than control (1.74 ± 0.06 g.fish-1), with prolific spawning starting 4 weeks earlier in the control ponds than in the PPT-ponds. This study demonstrated the potential of PPT for enhancing tilapia growth while delaying prolific breeding behaviour. Further studies should explore PPT in replacing synthetic hormones for sex-reversal of tilapia fry in hatcheries.","PeriodicalId":37296,"journal":{"name":"Asian Fisheries Science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42872881","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-06DOI: 10.33997/j.afs.2021.34.3.009
T. Tran, N. Thọ, N. T. Yen, N. X. Quang, N. Thao, Bijeesh Kozhikkodan Veettil
In recent decades, mangroves have been seriously devastated by shrimp farming development in the Vietnamese Mekong Delta. As a result, integrated mangrove-shrimp farming has emerged as a potential solution to culture shrimps and protect mangroves. The present study aims to understand whether mangrove-to-pond cover ratios influence shrimp yields in an integrated mangrove-shrimp farming system. Five integrated mangrove-shrimp ponds in the Tam Giang Commune, Nam Can District, Ca Mau Province (Southern Vietnam) were chosen for this study. The study estimated that the mangrove-to-pond cover ratios ranged from 42.00 % to 72.50 %. The total shrimp yield per year (kg.ha-1 yr-1 ) was generally high, ranging from 76.62 to 249.09 (including 37.93 to 108.64 for the black tiger shrimp (Penaeus monodon Fabricius, 1798), and 38.69 to 140.45 for other shrimps, namely Penaeus indicus Milne Edwards, 1837, Penaeus merguiensis de Man, 1888, Metapenaeus ensis (De Haan, 1844), and Metapenaeus lysianassa (de Man, 1888)). Moreover, a strong positive correlation between the mangrove-to-pond cover ratios and the shrimp yields were observed (r > 0.71, P < 0.05). In conclusion the mangrove-to-pond cover ratios have a direct impact on the total shrimp yield. The mangrove-to-pond cover ratios should be 50 % to enhance shrimp yields in this system.
{"title":"Effect of Mangrove Cover on Shrimp Yield in Integrated Mangrove-Shrimp Farming","authors":"T. Tran, N. Thọ, N. T. Yen, N. X. Quang, N. Thao, Bijeesh Kozhikkodan Veettil","doi":"10.33997/j.afs.2021.34.3.009","DOIUrl":"https://doi.org/10.33997/j.afs.2021.34.3.009","url":null,"abstract":"In recent decades, mangroves have been seriously devastated by shrimp farming development in the Vietnamese Mekong Delta. As a result, integrated mangrove-shrimp farming has emerged as a potential solution to culture shrimps and protect mangroves. The present study aims to understand whether mangrove-to-pond cover ratios influence shrimp yields in an integrated mangrove-shrimp farming system. Five integrated mangrove-shrimp ponds in the Tam Giang Commune, Nam Can District, Ca Mau Province (Southern Vietnam) were chosen for this study. The study estimated that the mangrove-to-pond cover ratios ranged from 42.00 % to 72.50 %. The total shrimp yield per year (kg.ha-1 yr-1 ) was generally high, ranging from 76.62 to 249.09 (including 37.93 to 108.64 for the black tiger shrimp (Penaeus monodon Fabricius, 1798), and 38.69 to 140.45 for other shrimps, namely Penaeus indicus Milne Edwards, 1837, Penaeus merguiensis de Man, 1888, Metapenaeus ensis (De Haan, 1844), and Metapenaeus lysianassa (de Man, 1888)). Moreover, a strong positive correlation between the mangrove-to-pond cover ratios and the shrimp yields were observed (r > 0.71, P < 0.05). In conclusion the mangrove-to-pond cover ratios have a direct impact on the total shrimp yield. The mangrove-to-pond cover ratios should be 50 % to enhance shrimp yields in this system.","PeriodicalId":37296,"journal":{"name":"Asian Fisheries Science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42970315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-30DOI: 10.33997/j.afs.2021.34.3.001
M. Gammanpila
The growth of marine bivalves is affected by the interactions of several environmental variables, particularly water salinity, temperature, and food supply. Influences of environmental parameters on daily weight gain (DWG), survival and heavy metal accumulation in 225 numbers of oysters, Crassostrea madrasensis (Preston, 1916), placed at five locations in the Negombo estuary, Sri Lanka, were investigated. One-way ANOVA indicated significantly higher (P < 0.05) DWGs (0.22 ± 0.01 and 0.16 ± 0.01 g.day-1) in Pitipana and Munnakaraya, where highest mean salinity (20.9 ± 0.34 ppt) and chlorophyll-a (5.41 ± 1.49 µg.L-1) were observed. Significantly lower growth rate (0.04 ± 0.02 g.day-1) recorded in Thaladuwa, where lowest salinity (13.29 ± 1.13 ppt), highest turbidity (19.26 ± 0.99 NTU) and ammoniacal nitrogen (0.368 ± 0.078 mg.L-1) were recorded. DWG showed a significant second-order polynomial relationships with chlorophyll-a (R² = 0.44, P < 0.05) and salinity (R² = 0.28, P < 0.05). Negative exponential relationships of DWG were evident with higher level of ammoniacal nitrogen (R² = 0.24, P < 0.05) and phosphate (R² = 0.25, P < 0.05). The high concentration of lead (1.883 mg.kg-1) exceeded the EU permissible limit of 1.5 mg.kg-1 (wet weight) in oysters’ tissue where urban wastewater is released to the lagoon. There appeared to be health concerns due to heavy metal accumulation in oyster tissues in polluted areas of the estuary. The findings of this study are useful for understanding the potential impacts of environmental changes on oyster resources and the long-term sustainability of oyster fisheries and aquaculture.
{"title":"Influence of Environmental Factors on Growth, Survival, and Heavy Metal Accumulation in Oyster, Crassostrea madrasensis (Preston, 1916) Cultivated in Negombo Estuary, Sri Lanka","authors":"M. Gammanpila","doi":"10.33997/j.afs.2021.34.3.001","DOIUrl":"https://doi.org/10.33997/j.afs.2021.34.3.001","url":null,"abstract":"The growth of marine bivalves is affected by the interactions of several environmental variables, particularly water salinity, temperature, and food supply. Influences of environmental parameters on daily weight gain (DWG), survival and heavy metal accumulation in 225 numbers of oysters, Crassostrea madrasensis (Preston, 1916), placed at five locations in the Negombo estuary, Sri Lanka, were investigated. One-way ANOVA indicated significantly higher (P < 0.05) DWGs (0.22 ± 0.01 and 0.16 ± 0.01 g.day-1) in Pitipana and Munnakaraya, where highest mean salinity (20.9 ± 0.34 ppt) and chlorophyll-a (5.41 ± 1.49 µg.L-1) were observed. Significantly lower growth rate (0.04 ± 0.02 g.day-1) recorded in Thaladuwa, where lowest salinity (13.29 ± 1.13 ppt), highest turbidity (19.26 ± 0.99 NTU) and ammoniacal nitrogen (0.368 ± 0.078 mg.L-1) were recorded. DWG showed a significant second-order polynomial relationships with chlorophyll-a (R² = 0.44, P < 0.05) and salinity (R² = 0.28, P < 0.05). Negative exponential relationships of DWG were evident with higher level of ammoniacal nitrogen (R² = 0.24, P < 0.05) and phosphate (R² = 0.25, P < 0.05). The high concentration of lead (1.883 mg.kg-1) exceeded the EU permissible limit of 1.5 mg.kg-1 (wet weight) in oysters’ tissue where urban wastewater is released to the lagoon. There appeared to be health concerns due to heavy metal accumulation in oyster tissues in polluted areas of the estuary. The findings of this study are useful for understanding the potential impacts of environmental changes on oyster resources and the long-term sustainability of oyster fisheries and aquaculture.","PeriodicalId":37296,"journal":{"name":"Asian Fisheries Science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49550811","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-30DOI: 10.33997/j.afs.2021.34.3.005
C. Chandan, Puja Roy, F. Khatun, N. C. Roy
The available commercial feeds in Bangladesh for fish larvae, including striped snakehead, (Channa striata (Bloch, 1793)), lack crude protein content. Therefore, for the proper biological well-being of striped snakehead larvae, formulating a protein-rich diet is necessary. The present experiment aimed to study the effect of three formulated isocaloric diets with varying levels of protein content on growth, survival, cannibalism, and mortality in striped snakehead (29 ± 3 mg of mean weight) weaning by rearing for 4 weeks. Three experimental groups depending on the dietary crude protein (CP 35 %, CP 40 %, and CP 45 %) were done in triplicate. Growth parameters (weight and length gain, specific growth rate, feed conversion ratio, and protein efficiency ratio) indicated better growth and feed utilisation in larvae fed CP 45 %, followed by 40 % and 35 % (P < 0.05). However, survival was not significantly different comparing the experimental groups. The cannibalism was maximum in CP 45 %, compared to 35 % and 40 %, most probably due to higher size heterogeneity, also confirmed by the co-efficient of variation in fish size. The observed mortality (not cannibalism) was higher in the group with lower protein (CP 35%) attributable to comparatively low feed intake and utilisation. Overall, the higher dietary protein levels demonstrated comparatively higher growth, possibly indicating the importance of increased protein content in snakehead larval feed.
{"title":"Effect of Dietary Protein on Growth, Survival and Cannibalism of Larval Striped Snakehead, Channa striata (Bloch, 1793)","authors":"C. Chandan, Puja Roy, F. Khatun, N. C. Roy","doi":"10.33997/j.afs.2021.34.3.005","DOIUrl":"https://doi.org/10.33997/j.afs.2021.34.3.005","url":null,"abstract":"The available commercial feeds in Bangladesh for fish larvae, including striped snakehead, (Channa striata (Bloch, 1793)), lack crude protein content. Therefore, for the proper biological well-being of striped snakehead larvae, formulating a protein-rich diet is necessary. The present experiment aimed to study the effect of three formulated isocaloric diets with varying levels of protein content on growth, survival, cannibalism, and mortality in striped snakehead (29 ± 3 mg of mean weight) weaning by rearing for 4 weeks. Three experimental groups depending on the dietary crude protein (CP 35 %, CP 40 %, and CP 45 %) were done in triplicate. Growth parameters (weight and length gain, specific growth rate, feed conversion ratio, and protein efficiency ratio) indicated better growth and feed utilisation in larvae fed CP 45 %, followed by 40 % and 35 % (P < 0.05). However, survival was not significantly different comparing the experimental groups. The cannibalism was maximum in CP 45 %, compared to 35 % and 40 %, most probably due to higher size heterogeneity, also confirmed by the co-efficient of variation in fish size. The observed mortality (not cannibalism) was higher in the group with lower protein (CP 35%) attributable to comparatively low feed intake and utilisation. Overall, the higher dietary protein levels demonstrated comparatively higher growth, possibly indicating the importance of increased protein content in snakehead larval feed.","PeriodicalId":37296,"journal":{"name":"Asian Fisheries Science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42678581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-30DOI: 10.33997/j.afs.2021.34.3.007
Gangadhar Barlaya, B. Kumar, G. Hegde, Hemaprasanth Kannur
Advanced fingerlings of Labeo fimbriatus (Bloch, 1795) were reared in aerated indoor plastic tanks to elucidate the dry matter and nutrient digestibility of cottonseed meal (CSM) in the feed. The fish were fed isocaloric formulated diets containing CSM replacing the main ingredients – groundnut cake and rice bran of the control diet at 10, 20, 30 and 40 % levels. Total dry matter digestibility and major nutrient digestibility were estimated using acid insoluble ash as the marker. In general, the digestibility of dry matter, protein, fat, and nitrogen-free extract was higher in CSM incorporated diets than the control diet. While the dry matter and nitrogen-free extract digestibility values were highest at 40 % CSM incorporation level, those for protein and fat digestibility were highest in 30 % and 10 % levels, respectively, showing an apparent reduction thereafter. The incorporation of CSM had a stimulatory effect on most of the intestinal digestive enzymes tested. Fish fed 20 % CSM diet recorded the highest activity of total protease and carboxypeptidases while those fed 30 % CSM diet had highest trypsin and amylase activities; all showing reducing trend consequently. In the case of hepatopancreas, the reducing trend in the activities of protease, chymotrypsin, carboxypeptidase A, and lipase observed with increased incorporation levels of CSM was significant (P < 0.05) and the reduction in the activities of trypsin, amylase and cellulase in CSM fed fish was not significant (P > 0.05). The study indicates the possibility of incorporation of CSM in the diet of L. fimbriatus up to 40 % level without affecting nutrient digestibility.
{"title":"Nutrient Digestibility and Digestive Enzyme Activity in Fringe Lipped Carp, Labeo fimbriatus (Bloch, 1795), Fed Diets Containing Cottonseed Meal","authors":"Gangadhar Barlaya, B. Kumar, G. Hegde, Hemaprasanth Kannur","doi":"10.33997/j.afs.2021.34.3.007","DOIUrl":"https://doi.org/10.33997/j.afs.2021.34.3.007","url":null,"abstract":"Advanced fingerlings of Labeo fimbriatus (Bloch, 1795) were reared in aerated indoor plastic tanks to elucidate the dry matter and nutrient digestibility of cottonseed meal (CSM) in the feed. The fish were fed isocaloric formulated diets containing CSM replacing the main ingredients – groundnut cake and rice bran of the control diet at 10, 20, 30 and 40 % levels. Total dry matter digestibility and major nutrient digestibility were estimated using acid insoluble ash as the marker. In general, the digestibility of dry matter, protein, fat, and nitrogen-free extract was higher in CSM incorporated diets than the control diet. While the dry matter and nitrogen-free extract digestibility values were highest at 40 % CSM incorporation level, those for protein and fat digestibility were highest in 30 % and 10 % levels, respectively, showing an apparent reduction thereafter. The incorporation of CSM had a stimulatory effect on most of the intestinal digestive enzymes tested. Fish fed 20 % CSM diet recorded the highest activity of total protease and carboxypeptidases while those fed 30 % CSM diet had highest trypsin and amylase activities; all showing reducing trend consequently. In the case of hepatopancreas, the reducing trend in the activities of protease, chymotrypsin, carboxypeptidase A, and lipase observed with increased incorporation levels of CSM was significant (P < 0.05) and the reduction in the activities of trypsin, amylase and cellulase in CSM fed fish was not significant (P > 0.05). The study indicates the possibility of incorporation of CSM in the diet of L. fimbriatus up to 40 % level without affecting nutrient digestibility.","PeriodicalId":37296,"journal":{"name":"Asian Fisheries Science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44496696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-30DOI: 10.33997/j.afs.2021.34.3.004
Karen A. Villarta, Annabelle del Norte Campos, Lorelie Burgos-Nuñeza
Gleaning activity in Malalison Island in Culasi, Antique, Philippines, was revisited and monitored monthly from May 2018 to April 2020 to compare with results from a previous investigation in 2003. Overall, slight differences were noted in the daily catch, effort, and catch rates between 2003 and 2020, whereas substantial differences were observed in the monthly and annual catches. A total of 26 species of molluscs were recorded, which was slightly lower than the previous number (= 30), dominated by the gastropods, Nerita albicilla Linnaeus, 1758, Nerita polita Linnaeus, 1758, Canarium urceus (Linnaeus, 1758), Conomurex luhuanus (Linnaeus, 1758), and Angaria delphinus (Linnaeus, 1758) which represented 79 % of the catch. The mean daily catch was 1.15 kg.gleaner-1 with catch rates ranging from 0.8 to 1.6 kg.day-1.gleaner-1, was slightly lower than the estimates in 2003 (0.9 to 2.5 kg.day-1). The observed mean monthly catch (29.6 kg) was considerably higher than the 2003 estimate (6.1 kg), which subsequently resulted in a higher estimated annual catch (1,867–2,178 kg), value (USD2,352–2,783), and gleaner income (USD392–464) in 2020 compared to estimates in 2003. Despite the changes in the catch, effort, and value estimated for the gleaning fishery in the island since 2003, locals continue to supplement their household incomes through gleaning. Nonetheless, additional investigations into the reproductive and population biology of the different species may be needed to understand further the dynamics of this fishery and its impacts on the species' ecologies.
{"title":"Reassessment of the Mollusc Gleaning Fishery in Malalison Island, Antique Province, West Central Philippines","authors":"Karen A. Villarta, Annabelle del Norte Campos, Lorelie Burgos-Nuñeza","doi":"10.33997/j.afs.2021.34.3.004","DOIUrl":"https://doi.org/10.33997/j.afs.2021.34.3.004","url":null,"abstract":"Gleaning activity in Malalison Island in Culasi, Antique, Philippines, was revisited and monitored monthly from May 2018 to April 2020 to compare with results from a previous investigation in 2003. Overall, slight differences were noted in the daily catch, effort, and catch rates between 2003 and 2020, whereas substantial differences were observed in the monthly and annual catches. A total of 26 species of molluscs were recorded, which was slightly lower than the previous number (= 30), dominated by the gastropods, Nerita albicilla Linnaeus, 1758, Nerita polita Linnaeus, 1758, Canarium urceus (Linnaeus, 1758), Conomurex luhuanus (Linnaeus, 1758), and Angaria delphinus (Linnaeus, 1758) which represented 79 % of the catch. The mean daily catch was 1.15 kg.gleaner-1 with catch rates ranging from 0.8 to 1.6 kg.day-1.gleaner-1, was slightly lower than the estimates in 2003 (0.9 to 2.5 kg.day-1). The observed mean monthly catch (29.6 kg) was considerably higher than the 2003 estimate (6.1 kg), which subsequently resulted in a higher estimated annual catch (1,867–2,178 kg), value (USD2,352–2,783), and gleaner income (USD392–464) in 2020 compared to estimates in 2003. Despite the changes in the catch, effort, and value estimated for the gleaning fishery in the island since 2003, locals continue to supplement their household incomes through gleaning. Nonetheless, additional investigations into the reproductive and population biology of the different species may be needed to understand further the dynamics of this fishery and its impacts on the species' ecologies.","PeriodicalId":37296,"journal":{"name":"Asian Fisheries Science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47093511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-30DOI: 10.33997/j.afs.2021.34.3.002
Harya Bimasuci, R. Adharini, Dini Wahyu Kartika Sari
Kappaphycus seaweed is the primary source of carrageenan, a polysaccharide widely utilised as a thickening and gelling agent in many commercial products. Unlike pure refined carrageenans, semi-refined carrageenans (SRC) are considered more cost-efficient and easier to produce. This study evaluates the quality of SRC extracted from Kappaphycus alvarezii (Doty) Doty ex Silva 1996, and Kappaphycus striatus (F. Schmitz) Doty ex P.C. Silva 1996, seaweeds farmed in the northern part of Java Island, particularly in Serang, Seribu Islands, and Karimunjawa Islands. Using 8 % KOH as a solvent, SRC was extracted from clean dried seaweed. Physical and chemical characteristics of the SRC were measured by assessing the percentage SRC yield, ash content, moisture, sulphate content, viscosity (cp) and gel strength (g.cm-2). Pearson’s correlation analysis was performed to investigate the relationship between SRC quality and environmental factors. Fourier transform infrared spectroscopy (FTIR) analysis showed that all samples had kappa-carrageenan from peak absorbance of 1218–1224 cm-1 indicating ester sulphate bonds, 924–925 cm-1 indicating 3,6–anhydrogalactose, and 843–844 cm-1 suggesting galactose–4–sulphate groups. Furthermore, ash content, moisture, and viscosity of SRC passed the FAO standard, while the sulphate content was below the threshold limit. Several environmental factors had a significant correlation with SRC quality, such as water pH positively correlated with gel strength, salinity level positively correlated with gel strength, and depth positively correlated with ash content. This study concluded that SRC produced from the sampling sites had varying qualities and may be affected by environmental parameters in their cultivation site.
Kappaphycus海藻是卡拉胶的主要来源，卡拉胶是一种多糖，在许多商业产品中广泛用作增稠剂和胶凝剂。与纯精制卡拉胶不同，半精制卡拉胶（SRC）被认为更具成本效益，更容易生产。本研究评估了从Kappaphycus alvarezii（Doty）Doty ex Silva 1996和Kappaphy库斯striatus（F.Schmitz）Doty ex.P.C.Silva 1996中提取的SRC的质量，这两种海藻在爪哇岛北部养殖，特别是在Serang、Seribu群岛和Karimunjawa群岛。以8%KOH为溶剂，从清洁干燥的海藻中提取SRC。通过评估SRC的产率、灰分、水分、硫酸盐含量、粘度（cp）和凝胶强度（g.cm-2）来测量SRC的物理和化学特性。采用Pearson相关分析来研究SRC质量与环境因素之间的关系。傅立叶变换红外光谱（FTIR）分析显示，所有样品的峰值吸光度为1218–1224 cm-1，表明存在酯-硫酸盐键，924–925 cm-1表明存在3,6-脱水半乳糖，843–844 cm-1表示存在半乳糖-4-硫酸盐基团。此外，SRC的灰分、水分和粘度均通过了FAO标准，而硫酸盐含量低于阈值限值。几个环境因素与SRC质量存在显著相关性，如水的pH值与凝胶强度呈正相关，盐度水平与凝胶强度正相关，深度与灰分呈正相关。本研究得出的结论是，从采样点生产的SRC具有不同的质量，并且可能受到培养点环境参数的影响。
{"title":"Characteristics of Semi-Refined Carrageenan From Kappaphycus Seaweed Farmed in Coastal Waters of Northern Java, Indonesia","authors":"Harya Bimasuci, R. Adharini, Dini Wahyu Kartika Sari","doi":"10.33997/j.afs.2021.34.3.002","DOIUrl":"https://doi.org/10.33997/j.afs.2021.34.3.002","url":null,"abstract":"Kappaphycus seaweed is the primary source of carrageenan, a polysaccharide widely utilised as a thickening and gelling agent in many commercial products. Unlike pure refined carrageenans, semi-refined carrageenans (SRC) are considered more cost-efficient and easier to produce. This study evaluates the quality of SRC extracted from Kappaphycus alvarezii (Doty) Doty ex Silva 1996, and Kappaphycus striatus (F. Schmitz) Doty ex P.C. Silva 1996, seaweeds farmed in the northern part of Java Island, particularly in Serang, Seribu Islands, and Karimunjawa Islands. Using 8 % KOH as a solvent, SRC was extracted from clean dried seaweed. Physical and chemical characteristics of the SRC were measured by assessing the percentage SRC yield, ash content, moisture, sulphate content, viscosity (cp) and gel strength (g.cm-2). Pearson’s correlation analysis was performed to investigate the relationship between SRC quality and environmental factors. Fourier transform infrared spectroscopy (FTIR) analysis showed that all samples had kappa-carrageenan from peak absorbance of 1218–1224 cm-1 indicating ester sulphate bonds, 924–925 cm-1 indicating 3,6–anhydrogalactose, and 843–844 cm-1 suggesting galactose–4–sulphate groups. Furthermore, ash content, moisture, and viscosity of SRC passed the FAO standard, while the sulphate content was below the threshold limit. Several environmental factors had a significant correlation with SRC quality, such as water pH positively correlated with gel strength, salinity level positively correlated with gel strength, and depth positively correlated with ash content. This study concluded that SRC produced from the sampling sites had varying qualities and may be affected by environmental parameters in their cultivation site.","PeriodicalId":37296,"journal":{"name":"Asian Fisheries Science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42309004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-30DOI: 10.33997/j.afs.2021.34.3.008
Puja Pati, K. Mondal, A. Pal
The current priority in the aquaculture industry is to replace fish meal with cheaper but efficient protein sources like plant-based feedstuffs to support global expansion and sustainability. Hence, research has focused on finding novel ways to increase the digestibility of plant-based diets. Exogenous enzymes have emerged as an excellent alternative to improve nutrient digestibility of the diet in animals, including fish. The present study aims to explore exogenous enzyme-producing bacteria in the gastrointestinal (GI) tract of Nile tilapia (Oreochromis niloticus (Linnaeus, 1758)). Two Gram-negative enzyme-producing (amylase, xylanase, and lipase) bacterial strains viz. Aeromonas veronii ONKP1 (GenBank accession no. MN602971) and Stenotrophomonas maltophilia ONKP2 (GenBank accession no. MN602972) were identified by biochemical tests and 16s RNA analysis. They are capable of utilising citrate, maltose, glucose, and gelatine. Besides, A. veronii ONKP1 can utilise mannitol, sucrose, and lactose, whereas S. maltophilia ONKP2 is catalase and urease positive. Aeromonas veronii ONKP1 was superior in terms of enzyme production to S. maltophilia ONKP2. Stenotrophomonas maltophilia ONKP2 is a rarely reported strain, specifically from healthy fish. Amylase, xylanase, and lipase could be used as feed additives for fermenting plant products and producing prebiotics like xylooligosaccharides. Further, this study might help understand the role of gut-associated bacteria viz. A. veronii and S. maltophilia, in fish nutrition.
{"title":"Characterisation of Extracellular Enzyme-Producing Microorganisms From the Gut of Nile Tilapia, Oreochromis niloticus (Linnaeus, 1758)","authors":"Puja Pati, K. Mondal, A. Pal","doi":"10.33997/j.afs.2021.34.3.008","DOIUrl":"https://doi.org/10.33997/j.afs.2021.34.3.008","url":null,"abstract":"The current priority in the aquaculture industry is to replace fish meal with cheaper but efficient protein sources like plant-based feedstuffs to support global expansion and sustainability. Hence, research has focused on finding novel ways to increase the digestibility of plant-based diets. Exogenous enzymes have emerged as an excellent alternative to improve nutrient digestibility of the diet in animals, including fish. The present study aims to explore exogenous enzyme-producing bacteria in the gastrointestinal (GI) tract of Nile tilapia (Oreochromis niloticus (Linnaeus, 1758)). Two Gram-negative enzyme-producing (amylase, xylanase, and lipase) bacterial strains viz. Aeromonas veronii ONKP1 (GenBank accession no. MN602971) and Stenotrophomonas maltophilia ONKP2 (GenBank accession no. MN602972) were identified by biochemical tests and 16s RNA analysis. They are capable of utilising citrate, maltose, glucose, and gelatine. Besides, A. veronii ONKP1 can utilise mannitol, sucrose, and lactose, whereas S. maltophilia ONKP2 is catalase and urease positive. Aeromonas veronii ONKP1 was superior in terms of enzyme production to S. maltophilia ONKP2. Stenotrophomonas maltophilia ONKP2 is a rarely reported strain, specifically from healthy fish. Amylase, xylanase, and lipase could be used as feed additives for fermenting plant products and producing prebiotics like xylooligosaccharides. Further, this study might help understand the role of gut-associated bacteria viz. A. veronii and S. maltophilia, in fish nutrition.","PeriodicalId":37296,"journal":{"name":"Asian Fisheries Science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46982776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-30DOI: 10.33997/j.afs.2021.34.3.003
Elmer G. Villanueva, K. Hoevenaars, J. Beijnen, A. Gonzales, L. Creencia, Roger G. Dolorosa
Three hatchery experiments for orange-spotted spinefoot, Siganus guttatus (Bloch, 1787), were carried out in Puerto Princesa City, Palawan, Philippines using larvae and fingerlings produced through induced spawning. The first experiment (E1) involving larvae raised in six 5,000-L concrete tanks until 39 days post-hatch (dph) comparing two stocking densities (T1: 3; and T2: 5 larva.L-1), obtained survival rates (SR) of 6.00 and 7.85 %. The second experiment (E2) monitored the growth and survival of 47 dph juveniles for 3 weeks, raised in 25-L plastic basins, fed with a commercial diet at three stocking densities with five replications. The initial stocking densities (6, 12, 18 ind.L-1) were reduced during the second (4, 8, 12 ind.L-1) and third (2, 4, 6 ind.L-1) week, respectively. The weekly SR for all treatments ranged between 99.2 and 100 %. Weekly final total lengths (TL) were not significantly different except during the second week. The third experiment (E3) evaluated the effects of two types of commercial feeds (T1: grouper feed; T2: milkfish feed) on the growth and survival of 47 dph juveniles in plastic basins for 3 weeks, at similar densities reduced on a weekly basis. The SR (96.2 to 99.9 %) were not significantly different, but the TL of fish in T1 (4.39 cm) were significantly bigger than in T2 (3.52 cm). While there is a need to improve the low and irregular survival of S. guttatus larvae for cost-effective large-scale production, we recommend using small basins in the intensive rearing of juveniles.
{"title":"Simplified Hatchery Protocols for Culture of Orange-Spotted Spinefoot Siganus guttatus (Bloch, 1787) in Palawan, Philippines","authors":"Elmer G. Villanueva, K. Hoevenaars, J. Beijnen, A. Gonzales, L. Creencia, Roger G. Dolorosa","doi":"10.33997/j.afs.2021.34.3.003","DOIUrl":"https://doi.org/10.33997/j.afs.2021.34.3.003","url":null,"abstract":"Three hatchery experiments for orange-spotted spinefoot, Siganus guttatus (Bloch, 1787), were carried out in Puerto Princesa City, Palawan, Philippines using larvae and fingerlings produced through induced spawning. The first experiment (E1) involving larvae raised in six 5,000-L concrete tanks until 39 days post-hatch (dph) comparing two stocking densities (T1: 3; and T2: 5 larva.L-1), obtained survival rates (SR) of 6.00 and 7.85 %. The second experiment (E2) monitored the growth and survival of 47 dph juveniles for 3 weeks, raised in 25-L plastic basins, fed with a commercial diet at three stocking densities with five replications. The initial stocking densities (6, 12, 18 ind.L-1) were reduced during the second (4, 8, 12 ind.L-1) and third (2, 4, 6 ind.L-1) week, respectively. The weekly SR for all treatments ranged between 99.2 and 100 %. Weekly final total lengths (TL) were not significantly different except during the second week. The third experiment (E3) evaluated the effects of two types of commercial feeds (T1: grouper feed; T2: milkfish feed) on the growth and survival of 47 dph juveniles in plastic basins for 3 weeks, at similar densities reduced on a weekly basis. The SR (96.2 to 99.9 %) were not significantly different, but the TL of fish in T1 (4.39 cm) were significantly bigger than in T2 (3.52 cm). While there is a need to improve the low and irregular survival of S. guttatus larvae for cost-effective large-scale production, we recommend using small basins in the intensive rearing of juveniles.","PeriodicalId":37296,"journal":{"name":"Asian Fisheries Science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46209895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-30DOI: 10.33997/j.afs.2021.34.3.006
N. Nanayakkara, K.P.L. Sandaruwan, W. Kumara, M. Rathnasuriya
Sri Lanka is one of the leading ornamental fish exporters globally, with total export earnings of around 15 million USD in 2019. The novel human coronavirus (COVID-19) pandemic has become a great threat to many industries worldwide, including the ornamental fish trade. The present study was conducted to explore the qualitative and quantitative impacts of the pandemic on the ornamental fish supply chain in the Western Province of Sri Lanka with a sample size of 100 respondents representing the key stakeholders of the supply chain. The results concluded that all the stakeholders experienced a negative impact on their business process with the ongoing pandemic. There was a general reduction in sales and along the supply chain, the fish exporters were the least affected sector (7 % reduction), followed by breeders and growers (31 %), and aquarium fish dealers (38 %). The stakeholders who handled a diversified fish stock managed to do better than those who dealt with a single fish species during the pandemic. The supply of fish feeds was one of the significant constraints for all the stakeholders during a complete and partial lockdown. As a positive outcome of the pandemic, 30 % of the fish exporters received an unexpected increased number of export orders from their buyers. Government intervention is crucial to rebuild and strengthen the impacted key players within the ornamental fish supply chain under the pandemic situation.
{"title":"Impacts of COVID-19 Pandemic on Ornamental Fish Supply Chain in Sri Lanka","authors":"N. Nanayakkara, K.P.L. Sandaruwan, W. Kumara, M. Rathnasuriya","doi":"10.33997/j.afs.2021.34.3.006","DOIUrl":"https://doi.org/10.33997/j.afs.2021.34.3.006","url":null,"abstract":"Sri Lanka is one of the leading ornamental fish exporters globally, with total export earnings of around 15 million USD in 2019. The novel human coronavirus (COVID-19) pandemic has become a great threat to many industries worldwide, including the ornamental fish trade. The present study was conducted to explore the qualitative and quantitative impacts of the pandemic on the ornamental fish supply chain in the Western Province of Sri Lanka with a sample size of 100 respondents representing the key stakeholders of the supply chain. The results concluded that all the stakeholders experienced a negative impact on their business process with the ongoing pandemic. There was a general reduction in sales and along the supply chain, the fish exporters were the least affected sector (7 % reduction), followed by breeders and growers (31 %), and aquarium fish dealers (38 %). The stakeholders who handled a diversified fish stock managed to do better than those who dealt with a single fish species during the pandemic. The supply of fish feeds was one of the significant constraints for all the stakeholders during a complete and partial lockdown. As a positive outcome of the pandemic, 30 % of the fish exporters received an unexpected increased number of export orders from their buyers. Government intervention is crucial to rebuild and strengthen the impacted key players within the ornamental fish supply chain under the pandemic situation.","PeriodicalId":37296,"journal":{"name":"Asian Fisheries Science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47883539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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