Pub Date : 2017-06-14DOI: 10.4172/2150-3508.1000206
Lekeufack Folefack Gb, A. Fomena
The spatial distribution of Myxobolus pethericii Fomena, Lekeufack folefack and Tang II, 2007 and Henneguya pethericii Fomena, Lekeufack folefack and Bouix, 2008 gills parasites of Ctenopoma petherici Gunther, 1864 was investigated. The gill apparatus of each host individual was divided into arbitrary regions and the number of cysts of each parasites species in each gill region was determined. Results were analysed at parasite species and xenocommunity levels. Site specificity was determined by application of Chi-square test to the data. At the same time, mean cyst loads were compared between different gill regions. The mean cyst load of the xenocommunity was higher on arches II and III than on arch IV. M. pethericii encysted more on outer hemibranch of arch IV. The medial segment of the gill was more colonized by M. pethericii and the combination made of M. pethericii+H. pethericii. The greater mean cyst load of M. pethericii was observed on medial segment. The specific preferences of a gill region might be affected by the interaction of factors such as the possible heterogeneity of the gill system, possible differences in the hydrostatic pressure of the bronchial pump and the water current over different parts of the gill surface.
{"title":"Spatial Distribution of Myxobolus Pethericii and Henneguya Pethericii on the Gills of an African Anabantid Ctenopoma Petherici from the Sange River, Cameroon","authors":"Lekeufack Folefack Gb, A. Fomena","doi":"10.4172/2150-3508.1000206","DOIUrl":"https://doi.org/10.4172/2150-3508.1000206","url":null,"abstract":"The spatial distribution of Myxobolus pethericii Fomena, Lekeufack folefack and Tang II, 2007 and Henneguya pethericii Fomena, Lekeufack folefack and Bouix, 2008 gills parasites of Ctenopoma petherici Gunther, 1864 was investigated. The gill apparatus of each host individual was divided into arbitrary regions and the number of cysts of each parasites species in each gill region was determined. Results were analysed at parasite species and xenocommunity levels. Site specificity was determined by application of Chi-square test to the data. At the same time, mean cyst loads were compared between different gill regions. The mean cyst load of the xenocommunity was higher on arches II and III than on arch IV. M. pethericii encysted more on outer hemibranch of arch IV. The medial segment of the gill was more colonized by M. pethericii and the combination made of M. pethericii+H. pethericii. The greater mean cyst load of M. pethericii was observed on medial segment. The specific preferences of a gill region might be affected by the interaction of factors such as the possible heterogeneity of the gill system, possible differences in the hydrostatic pressure of the bronchial pump and the water current over different parts of the gill surface.","PeriodicalId":166175,"journal":{"name":"Fisheries and Aquaculture Journal","volume":"143 43","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120929055","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 : 2017-06-12DOI: 10.4172/2150-3508.1000204
J. Jakobsen, Cat Smith
Fatty fish are generally stated as having high vitamin D content and among these are salmon and trout. In the aquaculture industry of salmonids the two main species produced are Salmo salar (Atlantic salmon) and Onchorhynchus mykiss (rainbow trout). Published data have shown lower content of vitamin D in farmed than in wild species, but generally data on vitamin D in farmed salmon and rainbow trout are scarce. In commercial production facilities we aimed to study the variation of vitamin D in farmed salmon and rainbow trout prepared for sale to consumer. Thirteen organically produced salmon and 18 rainbow trout were sampled within the range 0.7-4.0 kg of gutted weight. All fish were ready for consumption, and analysed for content of vitamin D3, 25-hydroxyvitamin D3, and fat. Mean vitamin D3 content in salmon and rainbow trout was 1.6 ± 0.5, and 5.0 ± 2.3 I¼g/100 g, respectively. Compared to vitamin D3, the content of 25-hydroxyvitamin D3 was 11% and 3%, respectively. In farmed salmon a linear relationship with vitamin D3 being dependent on weight (P<0.05) as well as to fat content (P<0.05), while no similar relationship was found for farmed rainbow trout. Despite this, both species exhibit a linear correlation between fat and gutted weight (P<0.001). The results indicate that there is a difference in the storage of vitamin D between the two salmonids, as 25- found in the salmonids is challenging farmed salmon and farmed trout as an essential vitamin D source.
{"title":"Farmed Salmon and Farmed Rainbow Trout-Excellent Sources of Vitamin D?","authors":"J. Jakobsen, Cat Smith","doi":"10.4172/2150-3508.1000204","DOIUrl":"https://doi.org/10.4172/2150-3508.1000204","url":null,"abstract":"Fatty fish are generally stated as having high vitamin D content and among these are salmon and trout. In the aquaculture industry of salmonids the two main species produced are Salmo salar (Atlantic salmon) and Onchorhynchus mykiss (rainbow trout). Published data have shown lower content of vitamin D in farmed than in wild species, but generally data on vitamin D in farmed salmon and rainbow trout are scarce. In commercial production facilities we aimed to study the variation of vitamin D in farmed salmon and rainbow trout prepared for sale to consumer. Thirteen organically produced salmon and 18 rainbow trout were sampled within the range 0.7-4.0 kg of gutted weight. All fish were ready for consumption, and analysed for content of vitamin D3, 25-hydroxyvitamin D3, and fat. Mean vitamin D3 content in salmon and rainbow trout was 1.6 ± 0.5, and 5.0 ± 2.3 I¼g/100 g, respectively. Compared to vitamin D3, the content of 25-hydroxyvitamin D3 was 11% and 3%, respectively. In farmed salmon a linear relationship with vitamin D3 being dependent on weight (P<0.05) as well as to fat content (P<0.05), while no similar relationship was found for farmed rainbow trout. Despite this, both species exhibit a linear correlation between fat and gutted weight (P<0.001). The results indicate that there is a difference in the storage of vitamin D between the two salmonids, as 25- found in the salmonids is challenging farmed salmon and farmed trout as an essential vitamin D source.","PeriodicalId":166175,"journal":{"name":"Fisheries and Aquaculture Journal","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131206104","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 : 2017-06-12DOI: 10.4172/2150-3508.1000205
Amitabh Ch, R. Dwivedi, P. Mayank, A. Tiwari
Good knowledge of netting approach is essential for scientific and sustainable based fisheries management in lotic water bodies. The large sizes of fishes are more attract to fishers compared to small fishes. This type of fishing is very harmful for future stock and recruitment. 1.5 inch to 3.5 inch mesh size cast net was used in the Ganga River at Allahabad. Cirrhinus mrigala is mainly captured by drag net from the Ganga River, India. Studies were undertaken during March 2014 to February 2015 from the middle stretch of the Ganga River, India. 423 fish specimens (206 males and 217 females) were examined of Cirrhinus mrigala. An over-all picture of age, growth increment and age composition of C. mrigala has been obtained by the study of its scales. The age composition of C. mrigala varied from 0+ to 10+. On the basis of pooled sampled specimen in the total length ranges varied from 16.8 cm to 92.4 cm showed that the fish attained the mean length 30.24 cm, 48.02 cm, 61.50 cm, 70.31, 77.63, 81.84 cm, 85.30 cm, 88.57 cm, 90.15 cm, 91.8 cm in 1+, 2+, 3+, 4+, 5+, 6+, 7+, 8+, 9+ and 10+ age groups respectively. The growth increments in C. mrigala was recorded as 30.24 cm, 17.78 cm, 13.48 cm, 8.81 cm, 7.32 cm, 4.21 cm, 3.46 cm, 3.27 cm, 1.58 cm and 1.65 cm for 1+ to 10+ age groups, respectively. The maximum growth increment was recorded in 1st year and minimum in 9th year of life. The slow growth increment observed after third year may be attributed to the maturity attained after second year of life. It is well known that the growth potential is used for the gonad development. Drag netting is reducing the size of C. mrigala in the Ganga River.
{"title":"Size Selectivity of Active Fishing Gear: Changes in Size, Age and Growth of Cirrhinus Mrigala from the Ganga River, India","authors":"Amitabh Ch, R. Dwivedi, P. Mayank, A. Tiwari","doi":"10.4172/2150-3508.1000205","DOIUrl":"https://doi.org/10.4172/2150-3508.1000205","url":null,"abstract":"Good knowledge of netting approach is essential for scientific and sustainable based fisheries management in lotic water bodies. The large sizes of fishes are more attract to fishers compared to small fishes. This type of fishing is very harmful for future stock and recruitment. 1.5 inch to 3.5 inch mesh size cast net was used in the Ganga River at Allahabad. Cirrhinus mrigala is mainly captured by drag net from the Ganga River, India. Studies were undertaken during March 2014 to February 2015 from the middle stretch of the Ganga River, India. 423 fish specimens (206 males and 217 females) were examined of Cirrhinus mrigala. An over-all picture of age, growth increment and age composition of C. mrigala has been obtained by the study of its scales. The age composition of C. mrigala varied from 0+ to 10+. On the basis of pooled sampled specimen in the total length ranges varied from 16.8 cm to 92.4 cm showed that the fish attained the mean length 30.24 cm, 48.02 cm, 61.50 cm, 70.31, 77.63, 81.84 cm, 85.30 cm, 88.57 cm, 90.15 cm, 91.8 cm in 1+, 2+, 3+, 4+, 5+, 6+, 7+, 8+, 9+ and 10+ age groups respectively. The growth increments in C. mrigala was recorded as 30.24 cm, 17.78 cm, 13.48 cm, 8.81 cm, 7.32 cm, 4.21 cm, 3.46 cm, 3.27 cm, 1.58 cm and 1.65 cm for 1+ to 10+ age groups, respectively. The maximum growth increment was recorded in 1st year and minimum in 9th year of life. The slow growth increment observed after third year may be attributed to the maturity attained after second year of life. It is well known that the growth potential is used for the gonad development. Drag netting is reducing the size of C. mrigala in the Ganga River.","PeriodicalId":166175,"journal":{"name":"Fisheries and Aquaculture Journal","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121500297","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 : 2017-05-28DOI: 10.4172/2150-3508.1000203
P. Dipak, Ey, Yong-Woon Ryu, T. Matsubara
Japanese anchovy (Engraulis japonicus) is a commercially and ecologically important fish that exhibits group synchronous and multiple spawning. However, the reproductive characteristics of the male in this species, especially sperm features and activation, are still largely unknown. In this study, we confirmed that features of the sperm and characteristics of the activations, regarding sperm motility and moving velocity. The average size of the sperm was 51 ± 1.3 I¼m in total length and possessed a normal structure with clockwise, anticlockwise, and linear motion. The initial motility at one minute after activation in seawater was 75 ± 12% during spawning time in this species (21:00â 22:00), and the initial moving velocity (196 ± 26 I¼m/sec) remained constant for fifteen minutes post activation. While, comparatively low motility (30 ± 10%) was found until 17:00, and the sperm was almost immotile in the morning (08:00â09:00). Swimming ability was also confirmed with sperm that swam for more than one hour in seawater without an exogenous energy supply derived from the ovary in females, suggesting the trigger for sperm activation in multiple spawning fish is possibly species dependent. This report is the first to demonstrate time specific activation, that is, circadian rhythm, in teleost males.
{"title":"Features of Sperm Motility and Circadian Rhythm in Japanese Anchovy(Engraulis japonicus)","authors":"P. Dipak, Ey, Yong-Woon Ryu, T. Matsubara","doi":"10.4172/2150-3508.1000203","DOIUrl":"https://doi.org/10.4172/2150-3508.1000203","url":null,"abstract":"Japanese anchovy (Engraulis japonicus) is a commercially and ecologically important fish that exhibits group synchronous and multiple spawning. However, the reproductive characteristics of the male in this species, especially sperm features and activation, are still largely unknown. In this study, we confirmed that features of the sperm and characteristics of the activations, regarding sperm motility and moving velocity. The average size of the sperm was 51 ± 1.3 I¼m in total length and possessed a normal structure with clockwise, anticlockwise, and linear motion. The initial motility at one minute after activation in seawater was 75 ± 12% during spawning time in this species (21:00â 22:00), and the initial moving velocity (196 ± 26 I¼m/sec) remained constant for fifteen minutes post activation. While, comparatively low motility (30 ± 10%) was found until 17:00, and the sperm was almost immotile in the morning (08:00â09:00). Swimming ability was also confirmed with sperm that swam for more than one hour in seawater without an exogenous energy supply derived from the ovary in females, suggesting the trigger for sperm activation in multiple spawning fish is possibly species dependent. This report is the first to demonstrate time specific activation, that is, circadian rhythm, in teleost males.","PeriodicalId":166175,"journal":{"name":"Fisheries and Aquaculture Journal","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127216687","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 : 2017-05-26DOI: 10.4172/2150-3508.1000202
A. M. Ahmed
This study was conducted to see the effects of seasons on fish production, in Jebel aulia dam south of Khartoum 45 km during the period January to December 2014, (containing 12 months) includes three seasons, summer, autumn and winter. 23 species belonging to 14 families were recorded during the period of investigation. Distribution production of fish in seasons as follow: in summer the high production is Tilapia in March 61.2%, April 53.3%, May 40%, finally June 32%. Bagrus bayad in March 9.9%, April 5.6%, May 12.6%, finally 4.9% in June. The fish which is rare is Disticodus niloticus and Citharinus citharus. High production months in the summer are June 36%, April 23%, March 21% and May 21%. In autumn the fish species which very high production is tilapia in July 25.9%, August 31.6%, September 33.5% and October 9.9% followed by Schall fish and Labeo niloticus. In winter the study found the high production of species is Tilapia, labeo niloticus and Hydrocon Forskalli. The months which is high production in winter containing November, December, February and January. The study showed that the fish production seasons are summer 37.15%, autumn 35.95% and finally winter 26.90%.
{"title":"Effects of Seasonal Variation on Fish Catching in Jebel Aulia Reservoir on the White Nile, Sudan","authors":"A. M. Ahmed","doi":"10.4172/2150-3508.1000202","DOIUrl":"https://doi.org/10.4172/2150-3508.1000202","url":null,"abstract":"This study was conducted to see the effects of seasons on fish production, in Jebel aulia dam south of Khartoum 45 km during the period January to December 2014, (containing 12 months) includes three seasons, summer, autumn and winter. 23 species belonging to 14 families were recorded during the period of investigation. Distribution production of fish in seasons as follow: in summer the high production is Tilapia in March 61.2%, April 53.3%, May 40%, finally June 32%. Bagrus bayad in March 9.9%, April 5.6%, May 12.6%, finally 4.9% in June. The fish which is rare is Disticodus niloticus and Citharinus citharus. High production months in the summer are June 36%, April 23%, March 21% and May 21%. In autumn the fish species which very high production is tilapia in July 25.9%, August 31.6%, September 33.5% and October 9.9% followed by Schall fish and Labeo niloticus. In winter the study found the high production of species is Tilapia, labeo niloticus and Hydrocon Forskalli. The months which is high production in winter containing November, December, February and January. The study showed that the fish production seasons are summer 37.15%, autumn 35.95% and finally winter 26.90%.","PeriodicalId":166175,"journal":{"name":"Fisheries and Aquaculture Journal","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133545588","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 : 2017-05-18DOI: 10.4172/2150-3508.1000201
Austin Saye Wehye, P. Ofori-Danson, A. Lamptey
The study evaluated some aspect of population parameters of Pseudotolithus senegalensis and Pseudotolithus typus within Liberia’s coastal waters. A total of 177 and 152 samples of P. senegalensis and P. typus respectively were collected from July to December, 2016. Individual fish samples was measured for standard length and analysed using FiSAT II software. From the results, P. senegalensis growth parameter were estimated at asymptotic length (L∞)=66.68 cm, growth rate (K)=0.13 yr-1, the longevity (tmax)=21.49 years, theoretical age at birth (t0)=-1.586 years and growth performance index (φ')=2.762. While P. typus growth parameters asymptotic length (L∞)=66.68 cm, growth rate (K)=0.14 yr-1, the longevity (tmax)=19.3 years, theoretical age at birth (t0)=-2.126 years and growth performance index (φ')=2.294. Mortality parameters for P. senegalensis and P. typus were calculated as total mortality rate (Z)=0.93 yr-1 and 0.70 yr-1, natural mortality rate (M)=0.37 yr-1and 0.39 yr-1 and fishing mortality rate (F)=0.56 yr-1 and 0.31 yr-1 respectively. The calculated fishing mortality rates (F) compared to Fopt=0.4M were beyond the limit for sustainable fishing. The exploitation rate (E) of P. senegalensis (E=0.60) was higher than the Eopt=0.5 criterion. It implies that P. senegalensis is overexploited while P. typus was at the peak of exploitation (E=0.45). Results from the study revealed that the P. senegalensis fishery in Liberia is slightly overexploited while P. typus is at the optimal level of exploitation; as well as the presence of growth overfishing within the two species population within Liberian coastal waters. Thus, to avert the consequences of growth overfishing, sustainable fisheries measures including monitoring of fishing efforts, and increase in mesh size should be implemented and enforced.
本研究评估了利比里亚沿海水域塞内加尔假蝇和典型假蝇种群参数的某些方面。2016年7 - 12月，共采集塞内加尔疟原虫177份，斑纹疟原虫152份。测量个体鱼样本的标准长度，并使用FiSAT II软件进行分析。由结果估计，塞内加尔稻的生长参数为渐近长度(L∞)=66.68 cm，生长速率(K)=0.13 yr-1，寿命(tmax)=21.49年，理论出生年龄(t0)=-1.586年，生长性能指数(φ')=2.762。typus的生长参数渐近长度(L∞)=66.68 cm，生长率(K)=0.14 year -1，寿命(tmax)=19.3年，理论出生年龄(t0)=-2.126年，生长性能指数(φ')=2.294。塞内加尔斑蝽和typus斑蝽的总死亡率(Z)分别为0.93和0.70年-1，自然死亡率(M)分别为0.37和0.39年-1，捕捞死亡率(F)分别为0.56和0.31年-1。与Fopt=0.4M相比，计算出的捕捞死亡率(F)超出了可持续捕捞的极限。senegalensis的开采率(E=0.60)高于Eopt=0.5的标准。结果表明，塞内加尔稻正处于过度开发阶段，而typus正处于开发高峰期(E=0.45)。研究结果表明，利比里亚的塞内加尔假鳗渔业处于轻度过度开发状态，而斑鸠渔业处于最佳开发水平;以及利比里亚沿海水域两种鱼类种群过度捕捞的增长。因此，为了避免过度捕捞增长的后果，应实施和执行可持续渔业措施，包括监测捕捞努力和增加网目尺寸。
{"title":"Population Dynamics of Pseudotolithus Senegalensis and Pseudotolithus Typus and Their Implications for Management and Conservation within the Coastal Waters of Liberia","authors":"Austin Saye Wehye, P. Ofori-Danson, A. Lamptey","doi":"10.4172/2150-3508.1000201","DOIUrl":"https://doi.org/10.4172/2150-3508.1000201","url":null,"abstract":"The study evaluated some aspect of population parameters of Pseudotolithus senegalensis and Pseudotolithus typus within Liberia’s coastal waters. A total of 177 and 152 samples of P. senegalensis and P. typus respectively were collected from July to December, 2016. Individual fish samples was measured for standard length and analysed using FiSAT II software. From the results, P. senegalensis growth parameter were estimated at asymptotic length (L∞)=66.68 cm, growth rate (K)=0.13 yr-1, the longevity (tmax)=21.49 years, theoretical age at birth (t0)=-1.586 years and growth performance index (φ')=2.762. While P. typus growth parameters asymptotic length (L∞)=66.68 cm, growth rate (K)=0.14 yr-1, the longevity (tmax)=19.3 years, theoretical age at birth (t0)=-2.126 years and growth performance index (φ')=2.294. Mortality parameters for P. senegalensis and P. typus were calculated as total mortality rate (Z)=0.93 yr-1 and 0.70 yr-1, natural mortality rate (M)=0.37 yr-1and 0.39 yr-1 and fishing mortality rate (F)=0.56 yr-1 and 0.31 yr-1 respectively. The calculated fishing mortality rates (F) compared to Fopt=0.4M were beyond the limit for sustainable fishing. The exploitation rate (E) of P. senegalensis (E=0.60) was higher than the Eopt=0.5 criterion. It implies that P. senegalensis is overexploited while P. typus was at the peak of exploitation (E=0.45). Results from the study revealed that the P. senegalensis fishery in Liberia is slightly overexploited while P. typus is at the optimal level of exploitation; as well as the presence of growth overfishing within the two species population within Liberian coastal waters. Thus, to avert the consequences of growth overfishing, sustainable fisheries measures including monitoring of fishing efforts, and increase in mesh size should be implemented and enforced.","PeriodicalId":166175,"journal":{"name":"Fisheries and Aquaculture Journal","volume":"228 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130866808","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 : 2017-05-17DOI: 10.4172/2150-3508.1000200
M. T. Kalhoro, M. Yongtong, M. A. Kalhoro, M. A. Mahmood, S. Hussain, M. Muhammad, P. T. Ramesh
The stock assessment, of Indian scad Decapterus russelli (Ruppell, 1830) from the northern Arabian Sea in Pakistan was evaluated. The samples of Indian scad (13300 specimens), ranging from 1-31 cm (FL) and 1-400 g (TW) were collected from the commercial fish landing center located at Karachi harbor. The parameters of fish length-weight relationship were calculated from the aggregated data as a=0.0323, b=2.66 with R2=0.954, indicating slightly negative allometric growth between the relationship. The length frequency samples from September 2013 to November 2014 was analyzed using FISAT II software, including the ELEFAN-I method. The growth parameters obtained using ELEFAN I was: L∞=32.55 cm, K=0.750 per year, t0=-0.678 with an Rn value of 0.220. Natural, total and fishing mortality M=1.42 per year, Z=3.84 per year at CI of 95% (CI=3.11-4.58) where F=2.422 per year and exploitation relation E=0.630 were obtained. Growth performance indices for L∞ and W∞ were performed using FiSAT-II program in order to estimate the limit and target reference points of stock exploitation were, Φ'=2.900 per year and Φ=0.170 per year, respectively. The results revealed that the natural fishing level of D. russelli (1.42 per year) was higher than the biological reference points F0.1 (0.85) and Fmax (0.9). Moreover the proportion of current mortality Fcurrent obtained was 0.630, representing that stock of D. russelli as highly exploited.It can be concluded from this study that the population parameters and the stock of D. russelli showed overexploitation in the northern parts of the Arabian Sea coast of Pakistan.
{"title":"Stock Assessment of Indian Scad, Decapterus Russelli in Pakistani Marine Waters and Its Impact on the National Economy","authors":"M. T. Kalhoro, M. Yongtong, M. A. Kalhoro, M. A. Mahmood, S. Hussain, M. Muhammad, P. T. Ramesh","doi":"10.4172/2150-3508.1000200","DOIUrl":"https://doi.org/10.4172/2150-3508.1000200","url":null,"abstract":"The stock assessment, of Indian scad Decapterus russelli (Ruppell, 1830) from the northern Arabian Sea in Pakistan was evaluated. The samples of Indian scad (13300 specimens), ranging from 1-31 cm (FL) and 1-400 g (TW) were collected from the commercial fish landing center located at Karachi harbor. The parameters of fish length-weight relationship were calculated from the aggregated data as a=0.0323, b=2.66 with R2=0.954, indicating slightly negative allometric growth between the relationship. The length frequency samples from September 2013 to November 2014 was analyzed using FISAT II software, including the ELEFAN-I method. The growth parameters obtained using ELEFAN I was: L∞=32.55 cm, K=0.750 per year, t0=-0.678 with an Rn value of 0.220. Natural, total and fishing mortality M=1.42 per year, Z=3.84 per year at CI of 95% (CI=3.11-4.58) where F=2.422 per year and exploitation relation E=0.630 were obtained. Growth performance indices for L∞ and W∞ were performed using FiSAT-II program in order to estimate the limit and target reference points of stock exploitation were, Φ'=2.900 per year and Φ=0.170 per year, respectively. The results revealed that the natural fishing level of D. russelli (1.42 per year) was higher than the biological reference points F0.1 (0.85) and Fmax (0.9). Moreover the proportion of current mortality Fcurrent obtained was 0.630, representing that stock of D. russelli as highly exploited.It can be concluded from this study that the population parameters and the stock of D. russelli showed overexploitation in the northern parts of the Arabian Sea coast of Pakistan.","PeriodicalId":166175,"journal":{"name":"Fisheries and Aquaculture Journal","volume":"127 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114642951","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 : 2017-05-08DOI: 10.4172/2150-3508.1000199
Obiyor Kelvin Ikenna, Nwani Chris Didigwu, Odo Gregory Ejikeme, Madu Josephine Chinenye, Ndudim Doris Ulumma Aguzie, Ifeanyi Oscar Ndimkaoha
The study on the fish fauna and physicochemical characteristics of Otamiri River was carried out for six months (June to August and October to December 2015). Samples were collected monthly from three sampling stations along the river. Eckman grab, scoop net, line and hook, cast net, traps and dugout canoe were used to collect the fish samples. Samples were collected from three stations, station 1 (dumpsite in the river), station 2 (dredging section) and station 3 (vegetable farming section). A total of 129 fishes belonging to 5 species, Synodontis budgetti, S. soloni, Chrysicthys nigrodigitatus, Clarias gariepinus and Papyrocranus afer were collected. Station 3 had the highest species composition (n=4) and fish abundance, 108 (83.7%), while station 1 had the least species composition (n=2) and the least fish abundance, 10 (7.8%). Temperature variation from June to December was wide at station 1 (25-28oC), unlike station 2 (27-28oC) and station 3 (28-29oC). A similar trend was replicated by Dissolved Oxygen (DO). Significant correlation of S. budgetti abundance and temperature (r=0.696, p<0.05), depth of river (r=-0.615, p<0.01) and turbidity (r=0.595, p<0.01) was observed. Similarly, a significant correlation of C. nigrodigitatus abundance and temperature (r=0.473, p<0.05), C. gariepinus abundance and depth (r=-0.481, p<0.05), P. afer abundance and temperature (r=0.530, p<0.05) was observed. Fish species abundance and composition in Otamiri River was significantly affected by anthropogenic activities.
{"title":"Benthic Fish Fauna and Physicochemical Parameters of Otamiri River, Imo State, Nigeria","authors":"Obiyor Kelvin Ikenna, Nwani Chris Didigwu, Odo Gregory Ejikeme, Madu Josephine Chinenye, Ndudim Doris Ulumma Aguzie, Ifeanyi Oscar Ndimkaoha","doi":"10.4172/2150-3508.1000199","DOIUrl":"https://doi.org/10.4172/2150-3508.1000199","url":null,"abstract":"The study on the fish fauna and physicochemical characteristics of Otamiri River was carried out for six months (June to August and October to December 2015). Samples were collected monthly from three sampling stations along the river. Eckman grab, scoop net, line and hook, cast net, traps and dugout canoe were used to collect the fish samples. Samples were collected from three stations, station 1 (dumpsite in the river), station 2 (dredging section) and station 3 (vegetable farming section). A total of 129 fishes belonging to 5 species, Synodontis budgetti, S. soloni, Chrysicthys nigrodigitatus, Clarias gariepinus and Papyrocranus afer were collected. Station 3 had the highest species composition (n=4) and fish abundance, 108 (83.7%), while station 1 had the least species composition (n=2) and the least fish abundance, 10 (7.8%). Temperature variation from June to December was wide at station 1 (25-28oC), unlike station 2 (27-28oC) and station 3 (28-29oC). A similar trend was replicated by Dissolved Oxygen (DO). Significant correlation of S. budgetti abundance and temperature (r=0.696, p<0.05), depth of river (r=-0.615, p<0.01) and turbidity (r=0.595, p<0.01) was observed. Similarly, a significant correlation of C. nigrodigitatus abundance and temperature (r=0.473, p<0.05), C. gariepinus abundance and depth (r=-0.481, p<0.05), P. afer abundance and temperature (r=0.530, p<0.05) was observed. Fish species abundance and composition in Otamiri River was significantly affected by anthropogenic activities.","PeriodicalId":166175,"journal":{"name":"Fisheries and Aquaculture Journal","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132454614","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 : 2017-04-28DOI: 10.4172/2150-3508.1000198
S. Long, R. ffrench-Constant, Kristian Metcalfe, M. Witt
The native European flat oyster (Ostrea edulis) has declined throughout its range, due to over-exploitation, a situation mirrored in oyster stocks globally. There are three remaining oyster fisheries in England (Fal, Solent, and Thames Estuary). The Fal oyster fishery though employs traditional methods, using hand-hauled dredges from rowing punts or under sail and is home to the last commercial sailing fleet in Europe. Against a backdrop of temporary closures to protect dwindling stocks in the Solent and Thames Estuary, this study considers whether the longevity of the Fal oyster fishery is linked to the traditional methods that have been employed for centuries. Using GPS tracking in combination with on board observers, we demonstrate that dredging under sail is inefficient compared to more modern mechanically powered methods that are utilised elsewhere. A review of historical landings suggests that both overall landings and fishing effort have declined. The fishery appears to have gone through cycles of over-exploitation and one closure due to disease. However, the key to the long-term survival of the Fal oyster fishery may be linked to the traditional method of dredging. It is estimated that a switch from traditional methods to modern techniques would result in a greater than 9 fold increase in effort per season. The data presented highlight this unique fishery as a counterfactual to the increases in power seen in commercial fisheries over the last century and serve as a reference point for future studies.
{"title":"Have Centuries of Inefficient Fishing Sustained a Wild Oyster Fishery: a Case Study","authors":"S. Long, R. ffrench-Constant, Kristian Metcalfe, M. Witt","doi":"10.4172/2150-3508.1000198","DOIUrl":"https://doi.org/10.4172/2150-3508.1000198","url":null,"abstract":"The native European flat oyster (Ostrea edulis) has declined throughout its range, due to over-exploitation, a situation mirrored in oyster stocks globally. There are three remaining oyster fisheries in England (Fal, Solent, and Thames Estuary). The Fal oyster fishery though employs traditional methods, using hand-hauled dredges from rowing punts or under sail and is home to the last commercial sailing fleet in Europe. Against a backdrop of temporary closures to protect dwindling stocks in the Solent and Thames Estuary, this study considers whether the longevity of the Fal oyster fishery is linked to the traditional methods that have been employed for centuries. Using GPS tracking in combination with on board observers, we demonstrate that dredging under sail is inefficient compared to more modern mechanically powered methods that are utilised elsewhere. A review of historical landings suggests that both overall landings and fishing effort have declined. The fishery appears to have gone through cycles of over-exploitation and one closure due to disease. However, the key to the long-term survival of the Fal oyster fishery may be linked to the traditional method of dredging. It is estimated that a switch from traditional methods to modern techniques would result in a greater than 9 fold increase in effort per season. The data presented highlight this unique fishery as a counterfactual to the increases in power seen in commercial fisheries over the last century and serve as a reference point for future studies.","PeriodicalId":166175,"journal":{"name":"Fisheries and Aquaculture Journal","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124505222","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 : 2017-04-28DOI: 10.4172/2150-3508.1000197
Z. Huicab-Pech, M. Castañeda-Chávez, F. Lango-Reynoso
Tilapia Oreochromis niloticus is an aquaculture resource that represents one of the most popular crops in the world. However, species cultivation presents health problems, which are associated with the presence of pathogenic bacteria and causes high economic losses. The aim of this study was to determine the diversity of these bacteria at the genus level in the species O. niloticus var. Styrling during growing stage in the fattening and pre-fattening phases. Tilapia samples were collected and analyzed; each sample was subjected to a macroscopic external and internal observation of organs and tissues. Subsequently, samples were evaluated by microbiological tests using Trypticase Soy Agar (TSA), Thiosulfate Citrate Bile Salts Sucrose Agar (TCBS) and selective media (Pseudomonas sp. Group), and conventional biochemical tests aimed at the production of glucose, sucrose, lactose, oxidase, catalase, indole, ornithine and Gram staining. External analysis revealed clinical signs of disease such as skin bleeding, body ulceration, corneal opacity, and intestine and vesicle inflammation. Microbiological and biochemical analysis showed the presence of eleven bacterial genera known as Arthrobacter sp., Enterococcus sp., Staphylococcus sp., Micrococcus sp., Streptococcus sp., Aeromonas sp., Pseudomonas sp., Edwardsiella sp., Flexibacter sp. and Flavobacterium sp., with a predominance of 55% Gram-negative bacilli in tilapia crops. According to the results, it is necessary to take preventive and corrective measures in order to avoid possible risks during production cycles, mainly when handling organisms. It is also important to promote good crop management practices and quality systems in production units to benefit the aquaculture sector.
{"title":"Pathogenic Bacteria in Oreochromis Niloticus Var. Stirling Tilapia Culture","authors":"Z. Huicab-Pech, M. Castañeda-Chávez, F. Lango-Reynoso","doi":"10.4172/2150-3508.1000197","DOIUrl":"https://doi.org/10.4172/2150-3508.1000197","url":null,"abstract":"Tilapia Oreochromis niloticus is an aquaculture resource that represents one of the most popular crops in the world. However, species cultivation presents health problems, which are associated with the presence of pathogenic bacteria and causes high economic losses. The aim of this study was to determine the diversity of these bacteria at the genus level in the species O. niloticus var. Styrling during growing stage in the fattening and pre-fattening phases. Tilapia samples were collected and analyzed; each sample was subjected to a macroscopic external and internal observation of organs and tissues. Subsequently, samples were evaluated by microbiological tests using Trypticase Soy Agar (TSA), Thiosulfate Citrate Bile Salts Sucrose Agar (TCBS) and selective media (Pseudomonas sp. Group), and conventional biochemical tests aimed at the production of glucose, sucrose, lactose, oxidase, catalase, indole, ornithine and Gram staining. External analysis revealed clinical signs of disease such as skin bleeding, body ulceration, corneal opacity, and intestine and vesicle inflammation. Microbiological and biochemical analysis showed the presence of eleven bacterial genera known as Arthrobacter sp., Enterococcus sp., Staphylococcus sp., Micrococcus sp., Streptococcus sp., Aeromonas sp., Pseudomonas sp., Edwardsiella sp., Flexibacter sp. and Flavobacterium sp., with a predominance of 55% Gram-negative bacilli in tilapia crops. According to the results, it is necessary to take preventive and corrective measures in order to avoid possible risks during production cycles, mainly when handling organisms. It is also important to promote good crop management practices and quality systems in production units to benefit the aquaculture sector.","PeriodicalId":166175,"journal":{"name":"Fisheries and Aquaculture Journal","volume":"99 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121385392","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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