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Research Article
Sep 15, 2017
Current Status of Three Major Carps (Labeo rohita, Cirrhinus mrigala and Catla catla) In the Downst ... ream Indus River, Sindh
Present study was conducted to analyze the status of commercial important three major carps (Cirrihinus mirrigala, Labeo rohita and Catla catla) at Downstream Indus River. The samples were collected from March 2015 to February 2016, from eight major landing areas. A total of 11912 fish specimen were collected from all sites. In this investigation 77 freshwater fish species were identified, including 71 native species and 6 exotic species. All of recoded 77 fishes were belonged to 9 orders and 23 families. In all of them Family Cypirinidae was observed as the dominant family with 24 fish species (26%) followed by Bagridae 13 fish species (14%). In this investigation, three important commercial species Cirrihinus mirrigala, Labeo rohita and Catla catla had been identified as the fish fauna of special concern. Those contribute in all catches only 4.28%, 3.53% and 1.64%, respectively. Population of these economically important species is declining due to overexploitation, habitat degradation and aquatic pollution. Therefore, effective conservation measures are suggested to sustain major carps and fish fauna at Downstream Indus River
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Research Article
Sep 15, 2017
Study on Existing Technology and Knowledge on Aquaculture by Fish Farmers in Gomastapur Upazila of ... Chapai Nawabgonj District, Bangladesh
A total of 150 farmers from three unions in Gomastapur upazila under Chapai Nawabgonj district were selected for determination of their aquaculture technology and knowledge. In this study, 83% of the fish farmers were adopted with extensive technology and rest 17% with semi-intensive technology. The aquaculture knowledge consisted of 6 levels such as, remembering, understanding, analyzing, synthesizing, evaluating and creating. The aquaculture knowledge of the fish farmers on different aspect of pond fish culture practices such as, pond biology, pond preparation, species selection and stocking density, water colour monitoring, pond fertilization, feed and feeding, disease control, harvesting and restocking, risk management and marketing revealed that most of the fish farmers belonged to low knowledge category. A few portion of the fish farmers had high knowledge. Most of the fish farmers had relatively better score on the first two levels (remembering and understanding) of knowledge. The farmers had low score on the analyzing, synthesizing, evaluating and creating component of knowledge. Among the personal characteristics of the farmers’ education, extension media contact and aquaculture training experience were observed to be significant and positively related with their fisheries knowledge. But age, total income, religious affiliation and family size of the respondents had no relation with aquaculture knowledge.
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Research Article
Sep 11, 2017
Length-weight Relationships and State of Well-being of Parachanna obscura Gunther1861, in Eleyele R ... eservoir, Southwestern Nigeria
The knowledge of length-weight relationship parameters has numerous practical applications in fishery research and management. However, there is currently dearth of information on the growth pattern and state of well-being of Parachanna obscura in Eleyele Reservoir. This study therefore investigates the allometry and condition factor of P. obscura inhabiting the Eleyele Reservoir, Southwestern Nigeria. 688 specimens of P. obscura were collected from artisanal fishers’ at their landing sites on a bimonthly basis for 24 months. Standard Length (SL, cm), and Body Weight (BW, g) were measured. Length-Weight Relationships (b>3 or <3-allometric; b=3-isometric), and condition factor (K) were calculated using standard formula. Data were analysed using descriptive statistics and ANOVA at α0.05. The SL and BW of P. obscura ranged from 10.6 to 39.2 and 15.3 to 830.5 respectively. The LWR were 3.04 (male) and 2.99 (female) indicating positive allometric pattern of growth in male and negative allometric growth in female. The growth coefficient b ranged between 2.877 in July and 3.348 in May, with very significant coefficient of determination r2 for all the months. Variations recorded in the b value of different size groups showed positive allometric growth in 10.1 cm -15.0 cm, 15.1 cm -20.0 cm and 20.1 cm -25.0 cm, but negative allometric growth in 25.1 cm -30.0 cm and 30.1 cm -40.0 cm. The maximum (1.54 ± 0.12) K was noticed during March 2016 and the minimum (1.30 ± 0.7) K in September 2015. Significant variation occurred in K with size groups. The mean K value in females (1.43 ± 0.21 and 1.44 ± 0.20) was higher than males (1.40 ± 0.18 and 1.42 ± 0.17) for 2014-2015 and 2015-2016, respectively. The results indicated that P. obscura were thriving very well in Eleyele Reservoir.
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Research Article
Aug 31, 2017
Heavy Metals in Farm Sediments, Feeds and Bioaccumulation of Some Selected Heavy Metals in Various ... Tissues of Farmed Pangasius hypophthalmus in Bangladesh
In these studies, we had determined the concentrations of heavy metals in P. hypophthalmus including sediment, water and Fish organs (gills, flesh, and liver) in order to evaluate the possible risk of consumption. Concentration of heavy metal was not significantly presence of water whereas heavy metal in sediment Ni: 26.31 mgkg-1-33.03 mgkg-1; Cu: 13.00 mgkg-1-23.20 mgkg-1; Cr: 7.31 mgkg-1-15.41 mgkg-1; Pb: 6.43 mgkg-1-8.65 mgkg-1; Cd: BDL (Below Detection Limits) were higher than that of fish parts (Cu-11.96, Pb-6.29, Cd-0.16 Ni-4.23, and Cr-11.03) mgkg-1Metal concentration in fish feed followed the sequence Cr>Cu>Ni>Pb>Cd and found that both farm feeds were more or less same quality except one or two metals. The concentration of heavy metals recorded in the fish parts also indicated a certain degree of bio-accumulation. The concentration of all metals in water were below the WHO and FEPA recommended limits and suggested that the water of the farm are safe and suitable for use, but the concentration of heavy metals in gills, kidney and liver of the fish are high beyond the tolerable level, which indicated that as far as these metals are concerned, the fish is unfit for human consumption.
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Research Article
Aug 31, 2017
The predatory behaviour of nymphs of dragonfly (Africocypha varicolor) on fry of African mud catfis ... h (Clarias gariepinus) and control by skunk weed (Petivera alliacea) root-extract in aquaculture
The use of natural organic extract instead of synthetic chemicals in harvesting wild fish and eliminating unwanted aquatic biota is popular in Nigeria. This research, therefore, investigated the possibility of using the root extract of a common weed in southwestern Nigeria, named P. alliacea, in checkmating the predatory influence of nymphs of dragonfly which frequently attack fry of African mud catfish. Activity of extract was first assessed through a brine shrimp test in a 24 hr investigation before concentrations of 0.0 g/l, 0.22 g/l, 0.48 g/l, and 1.06 g/l were applied under laboratory conditions in plastic aquaria against the naiads. The 96 hr Lc50 was 0.47 g/l obtained using probit analysis. The regression equation for the probit curve was y=3.173+3.5 (y=probit value, x=actual concentration and r=0.7=coefficient of correlation). An average of six fry and one fry were consumed by one dragonfly nymph every 96 hr at two weeks and three weeks old, respectively.
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Research Article
Aug 24, 2017
Metal Uptake and Bioaccumulation Potentials of Clarias Buthupogon and Heterobranchus Longifilis Col ... lected from Asa River, Ilorin, Nigeria
Despite the existence of environmental legislations in Nigeria, aquatic environment has remained the sewer for wastes not minding its implications on the resident resources. Heavy metals pollution has become a worldwide concern and this may be due to their ability to bioaccumulate in aquatic organisms which is a source of livelihood for human populations. Therefore, this work aimed at assessing heavy metal accumulation in Clarias buthupogon and Heterobranchus longifilis in Asa River, Nigeria. After reconnaissance survey, fish samples were collected using hooks, traps and cast nets of various sizes twice monthly between April 2011 and March 2013 and were identified immediately. The samples were processed and heavy metal concentrations were determined in the gill, liver and muscle using atomic absorption spectrophotometer. Different metals were analysed in the gill, liver and muscle of the sampled fish species and the data obtained were subjected to statistical analysis using the T-test statistical package to determine the level of difference between means. The results in (mg kg-1, dry weight) showed different levels of the analysed metals in the two fish species. The order of heavy metals accumulation in the two fish species are gills>liver>muscle and the levels of heavy metals bioaccumulation varied significantly (p<0.05) among season, sample locations, fish species and fish organs. All metals analysed vary significantly in the two fish species examined, seasons and across sampling sites. The results suggest that Asa River has high pollution loads of these heavy metals in fishes due to an indiscriminate of discharge of effluents in the river and could pose a health hazards to man. Consequently, close monitoring of heavy metal loads in Asa River is recommended with a view of minimizing the risks to health of the population that depend on the river for their water and fish supply.
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Research Article
Aug 15, 2017
Phenetic Relationship Study of Gold Ring Cowry, Cypraea Annulus (Gastropods: Cypraeidae) in Molluca ... s Islands Based on Shell Morphological
This study aims to construct taxonomic character of Cypraea annulus based on shell morphological; analyzed the developmental stages of the snail shell and investigated the similarities and phenotypic distances of snails with numerical taxonomic approaches. This research lasted four years on island of Larat and Ambon. The sample used was 2926. Construction of morphological taxonomic characters using binary data types with 296 test characters and ordinal types with 173 test characters; and 32 specimens of operational taxonomic units. The data is processed and analyzed on Lasboratory of Maritime and Marine Study Centre, University of Pattimura. The results of this study indicate that the development stages of C. annulus shell: juvenile stage (11.00-14.99 mm), sub adult (15.00-18.99 mm), adult (19.00-22.99 mm) and post adult (>23.00 mm). The distribution of similarity coefficient and phenetic distance values between 32 OTU C. annulus has a morphological phenetic similarity in the range of values above 95% and the phenetic distance in the range of less than 1.0. C. annulus numerical taxonomic based on morphological taxonomic character with 296 characters of test at binary data type, obtained two taxa phenotypes at a taxonomic phenon similarity level of 94%; Whereas with 173 character test of ordinal data type, obtained three taxa phenotype at taxonomic correlation level 0.970.
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Research Article
Aug 11, 2017
Understanding the Role of Fish Farmer Associations as Intermediaries for the Commercialization of A ... quaculture in Uganda
Aquaculture development commentary supports the formation of fish farmer associations or producer organizations as avenues for cultivating small- and medium-scale commercial farmers. However, little is known about the types of associations that facilitate commercialization. This research presents four qualitative case studies, based on semi-structured interviews, profiling existing associations of commercial fish farmers in Uganda. We conclude that the umbrella organizations under which local fish farmer associations vertically align themselves have important implications for fish farmer production. Aquaculture-specific umbrella organizations contribute to the success of local member association’s more than general umbrella organizations do. Successful fish farmer associations accept government assistance only when it directly improves their fish farm operations. Other farmer groups seemed to wait for direct subsidization. Training fish farmers, providing quality information, cost sharing, and advocating for the aquaculture sector, not donor seeking, are the top priorities in productive fish farmer associations.
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Research Article
Aug 08, 2017
Isolation and Identification of Pathogenic Fungus from African Catfish (Clarias gariepinus) Eggs an ... d Adults in National Fishery and Aquatic Life Research Center Hatchery, Ethiopia
Isolation and identification of pathogenic fungi from African Catfish (Clarias gariepinus) eggs and adults in Ethiopian National Fishery and Aquatic Life Research Center hatchery was conducted from October 2015 to May 2016. The aim of this study was to investigate the aquatic fungal flora associated with eggs and brood stock from African catfish in the center. A total of 16 egg samples, 77 swab samples from skin of adult fishes (brood stock) and water samples from 14 incubating containers were investigated. Samples were collected from water, outer body surface of fish as well as from artificially hatched eggs. Isolation and identification of the fungus was done on colonial and microscopic characteristics. In this study, 84.11% samples were positive for fungal growth and fungus isolates belonging to seven different genera were identified. Tricophyton, Saprolegnia, Rhizopus, Penicillium, Mucor, Microsporum and Alternaria were among the dominant isolated fungal genera. Among the isolated genera, Tricophyton was detected from 13.08% of the samples, while Alternaria had the least with 3.74%, unidentified fungi accounts for 14.02% and unidentified yeast were 20.56%. Based on the results, various pathogenic fungi species were identified from fish body, water and hatched eggs, hence are potential causes of mortality and decreased egg hatchability. In the light of this, appropriate egg and water disinfection methods are essential for hatchery management. Fishes in rearing facilities must be given proper health management monitoring to prevent outbreak of fungal disease
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Research Article
Jul 29, 2017
The Acute Effects of Un-ionized Ammonia on Zebrafish (Danio rerio)
Zebrafish is a commonly used species in toxicology studies investigations such as molecular genetics, histopathology and developmental biology. A toxicity test was conducted to investigate the effects of toxic ammonia (NH3) in relation to time and concentration by establishing a measurable endpoints for chemical exposure and monitoring the biological responses on zebrafish exposed to high levels of toxic ammonia concentration using ammonium chloride (NH4Cl) as E1: 17.21 mg/l, E2: 24.51 mg/l, E3: 25.81 mg/l, E4: 32.11 mg/l and E5: 38.91 mg/l NH3-N at 24 hr, 48 hrs and 72 hrs periods. Fish exposed to the high levels of toxic ammonia exhibited hematological, histopathological and molecular alterations to the gills, liver and kidney at all exposure periods 24 hrs, 48 hrs and 72 hrs. The interrelation between the hematological, histopathological and gene expression have proven to be time and dose dependent having a linear relation under the influence of high levels of toxic ammonia exposure. Such hematological and histopathological changes observed in the liver and kidney of zebrafish in the present study indicates that the fish were responding to the direct effects of the toxic ammonia and secondary effects caused by stress
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Research Article
Jul 17, 2017
A Model for Self-Sustaining Litopenaeus Vannamei Farm Alternatives
We investigate a semi-contained, two-tank model for a Litopenaeus vannamei (White Pacific Shrimp) aquaculture farm. Our model simulates the possibility of a self-sustaining aquaculture system, with an interdependent triad of shrimp, algae, and bacteria. The two tanks are symmetric: the first containing developing shrimp through the hatchery and nursery phase and the second containing full grown shrimp through the grow-out phase. This system is modelled by six, first order differential equations. Using analytic and numeric techniques, we examine the dynamics and equilibria of this system as well as each of its individual components. This paper examines the effects of varying harvesting frequencies and magnitudes, and searches for an optimal harvesting strategy. Our analysis concluded that in the confines of our model, a technique of harvesting 81.5% of harvestable shrimp every 2 days provides a hypothetical optimal strategy. However, upon consideration of practical constraints, a harvesting strategy of 98% of harvestable shrimp every 10 days represents a real-world optimal harvesting strategy.
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Research Article
Jul 07, 2017
Nodaviruses in Wild Fish Population Collected Around Aquaculture Cage Sites from Coastal Areas of T ... unisia
This report describes the viral epidemiology of wild fish adjacent to cage farms within the Tunisian coasts and is focused on viral nervous necrosis virus (VNNV). A total of 92 apparently healthy wild marine fish were collected near aquaculture facilities in five different coastal areas of Tunisia. The brains and eyes of fish were examined by quantitative real time reverse transcriptase-polymerase chain reaction (qRT-PCR) to detect the nodavirus coat protein gene of. A total of 57 out of 92 (61.9%) samples were positive for nodavirus by qRT-PCR. This finding indicates that carrier fish occur at a considerable level in populations of wild marine fish. Samples from 13 fish species were found to be positive to the virus genome: Sarpa salpa, Trachurs trachurus, Boobs boops, Sardinella aurita, Diplodus vulgaris, Diplodus puntazzo Liza aurata, Diplodue sargus, Sparus aurata, Sardina pilchardus, Spicara maena, Spondyliosoma cantharus, and Diplodus annularis. The partial sequences of the RNA2 coat protein gene of these strains were identical with RGNNV type previously identified within farmed sea bass and sea bream species in Tunisia, with a homology >97%. With respect to the proximity of the sampling sites to the coast and to rearing facilities, results analysis can suggest that these viruses may be indigenous to Tunisian coastal waters.
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Research Article
Jun 23, 2017
Variation in the Morphometry Measurements of Two Tilapia Fish Species in Relation to Their Body Wei ... ght Obtained from Lower Benue River at Makurdi, Benue State Nigeria
This study examined the morphometry of Tilapia zilli and Oreochromis niloticus from lower River Benue at Makurdi. Seven morphometry measurements (body weight, standard length, total length, dorsal fin length, caudal fin length, head length and body width) of each captured fish. The mean of morphological parameters of Tilapia zilli of body weight, standard length, total length, dorsal fin length, caudal fin length, head length and body width were 12.83 g, 8.00 cm, 9.95 cm, 4.50 cm, 3.19 cm, 2.27 cm and 4.44 cm respectively. Similarly the mean morphometry of Oreochromis niloticus was body weight: 15.51 g, standard length: 9.00 cm, total length: 10.76 cm, dorsal fin length: 5.85 cm, caudal fin length: 3.68 cm, head length: 2.67 cm and body width: 4.41 cm. The correlation analysis between morphometry of Tilapia zilli was significant between head length and total length only. However, correlation analysis between morphometry of Oreochromis niloticus revealed a significant positive correlation between standard length and bodyweight, total length and body weight, standard length and total length, dorsal fin length and body width and head length and dorsal fin length only. There was a strong relationship between log of body weight and standard length using regression analysis with R2 value of 0.8689 in Oreochromis niloticus while a weak relationship was obtained in Tilapia zilli with R2 value of 0.0889 during the study. The study concludes that the two species of the Tilapia are different with different morphological features used in its identification.
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Research Article
Jun 21, 2017
Heavy Metals (Lead, Cadmium and Nickel) Concentration in Different Organs of Three Commonly Consume ... d Fishes in Bangladesh
Pollution and food safety are concerning issues in recent years. For that, the present investigation was aimed to determine the levels of heavy metals (Lead, Cadmium and Nickel) in different organs of three fish (Labeo rohita, Gibelion catla and Pangasius hypophthalmus) and to compare the present value with Food and Agriculture Organization (FAO)/World Health Oraganization (WHO) acceptable limit. These commonly consumed fish were collected from Kawran Bazar fish market, Bangladesh and the concentrations of heavy metals were carried out using Atomic Absorption Spectrophotometer. The highest (48.33 ± 2.52 ppm) concentration of Lead (Pb) was found in the gill of Pangus fish and the lowest (23.33 ± 2.52 ppm) was found in the gonad of Rui fish. In case of Cadmium (Cd), the highest (0.96 ± 0.08 ppm) concentration was found in the gill of Rui fish whereas the lowest (0.02 ± 0.01 ppm) was found in the kidney of Pangus fish. The highest (6.63 ± 1.00 ppm) concentration of Nickel (Ni) was found in the gill of Katla fish and the lowest (0.10 ± 0.10 ppm) was found in the liver of the same species. The metal concentrations in the muscle of Rui, Katla and Pangus fish were in the decreasing order of Pb>Ni>Cd, Pb>Cd>Ni and Pb>Ni>Cd respectively. In the study, it was found that Pb has exceeded the limits in every case whereas Cd was within the limits except for a few and Ni was completely within the maximum allowable limits provided by FAO/ WHO. However, all these concentrated metals in different parts of fish body could be concentrated into human body, if they are consumed and if so happen; there will be a massive health risk for us.
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Research Article
Jun 14, 2017
Spatial Distribution of Myxobolus Pethericii and Henneguya Pethericii on the Gills of an African An ... abantid Ctenopoma Petherici from the Sange River, Cameroon
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 branchial pump and the water current over different parts of the gill surface
