Stock Assessment Of Trout Soecies In Upper River Swat
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Publisher: 2013 Dissertation note: Abstract
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Possible Causes Of Selective Lernaea Attack On Different Fish Species
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Publisher: 2013 Dissertation note: The present study was managed to investigate the possible causes of selective Lernaea attack in different fish species. Planned studies were conducted in five trials. During the first trial lernaea susceptibility and infestation were observed in indigenous major and exotic Chinese carps. Studies were conducted in 4 earthen ponds with two ponds per experimental group. Fishes in the both groups were fed isonitrogenous diet containing 40% crude protein formulated with different feed ingredients. Fishes were identified and examined for the presence of Lernaea species. The parasites were removed and preserved in vials containing 5% formalin. Other growth parameters i.e. average weight gain, average increase in length while physico-chemical analysis including dissolved oxygen, pH, electrical conductivity, water temperature, salinity and total dissolved solids, Chlorides, Phosphates ions (PO4-2), nitrates (NO3) and secchi disk visibility were recorded. The fishes were treated with Tender, an organophasphate (DDVP (Dichlorvos) or 2, 2-dichlorovinyl dimethyl phosphate) for the control of lernaea.
The results showed that C. catla is the most susceptible fish to L. cyprinacea infestation and its appropriate control for conservation of this precious and declining fish is of extreme importance. Thunder is biologically safe as it is biodegradable and degenerated after 36 h without causing any negative effect on the water quality parameters and other water flora and fauna. Treatment of L. cyprinace with 'Thunder' (0.10-0.25ppm) gives promising results without adverse effect on fish life. Though DDVP worked well in its control but its heavy infestation really weaken fish incapacitating its feeding and competing abilities with its counterparts.
In the 2nd trial, comparison of bio-chemical profile was observed on healthy and infected Indian and Chinese major carps. The experiment was managed in four earthen rearing ponds (59m x 30.5m x 1.8m). There were two-groups, one group without any treatment served as control and the second as treatment. At the outset of trial all the fish species were weighed, measured and comprehensively examined for presence of L. cyprinacea and general health condition. Fishes from both groups were dealt uniformly except administration of regular applications of DDVP (0.25ppm in treatment group while no any medication in control group. Water quality parameters DO, pH, electrical conductivity, water temperature, salinity and total dissolved solids, chloride ion (Cl-1), phosphate ions (PO4-2) nitrates (NO-3) and light penetration were recorded. Samples of healthy and infected fishes of each species were collected for proximate composition (moisture, ash, crude protein, crude fat) and minerals (Iron, Zinc, Calcium, Copper and Magnesium) and phosphorous analysis.
The results showed that dry matter, fat and crude protein percentages were significantly decreased in lernaeid fishes. Moisture and ash contents of fishes increased in infected fishes as compared to healthy and treated fish. A slightly lower level of protein (12.65±0.49) and fat (7.30±0.28) in C. catla was observed than rest of the species. The protein was the highest (26.00±4.24) in L. rohita while the fats were the highest (10.55±0.92) in C. mrigala and C. carpio the second highest. Similarly looking at mineral profile there is not much difference, so it is hard to say that level and type of nutrients are solely responsible for L. cyprinacea attack. Mineral composition of infected fish indicated that minerals balance upsets during disease condition. Pathogenicity is a complex of so many factors, which encompass environmental, biological, and physiological so still lot remains to be explored before issuance of any concrete conclusion and recommendation that which factor is more active and critical in inviting and attracting this parasite.
In the third experiment, various blood indices were compared among Chinese and Indian major carps from the perspectives of their resistance against lernaeaosis that included probable role of blood and its components in reception of L. cyprinacea in some commercially important locally culturable herbivorous fish varieties while repulsion in others living under similar environment.
Healthy samples of each fish species were selected and blood was immediately drawn by puncturing gill lamellae, caudal vein and heart of both male and female of each representative experimental species. Blood parameters including Red Blood Cells (RBC, 10 -6/µL), White Blood Cells (WBC, 10-3/µL) and Platelets (10-3/µL) in blood from experimental fish species were counted by placing sample on haemocytometer grids. Differential Leucocyte Count (DLC), red blood indices, blood chemistry and ESR were determined for males and females of experimental fishes.
The results revealed that females of each species have relatively higher values for blood indices as compared to males. C. carpio has maximum number of granulocytes that may support the fish against the parasitic attack. C. catla has the lowest values for the immunoglobulin Ig M as compared to the species which showed less susceptibility.
In the 4th trial, healthy fishes of major and Chinese carps were collected from commercial rearing and grow out ponds. Each fish weighed 830 ± 316 g on the average. For mucus collection, fishes were bathed in Potassium permanganate (KMnO4) solution (8.0 ppm) to remove microbial or fungal infection/infestation. Samples were centrifuged at 12000×g at 4 ?C for 10 minutes and stored at -40?C in biomedical freezer. Bradford Micro Assay technique was applied to determine protein contents. Bradford protein solution (50 ?L) was added to each well and absorbance was recorded at 595nm. Standard curve was drawn from various but consecutive dilutions of BSA solution and protein concentrations in different samples were calculated. Electrophoresis was carried out with slight modifications. 15% separating and 4% staking buffer were used to run the SDS- PAGE under constant voltage of 120. Fermentas PageRuler™ protein ladder was used as the standard marker for non reducing protein. The gel was stained with PageBlue™ (Fermentas) stain for identification of protein bands for molecular weight determination. Lectin activity and Alkaline Phosphatase test were determined. Mucus was incubated with 4 mM p-nitrophenyl phosphate in ammonium bicarbonate buffer (100 mM) with 1 mM MgC12 (pH 7.8) at 30°C. The increase in optical density (OD) was measured continuously for 2 to 3 hours at 405 nm using a micro plate reader.
The results showed that lectin activity was the highest in C. idellus (109) indicative of low resistance while it was the lowest (21) in H.molitrix which was completely parasite free. Alkaline phosphatase level was the highest in C. catla, C.idella was the second highest and was the lowest in C. carpio. Protein concentrations were the highest in C. idella (3.29 ± 0.13 mg/ml) and C. catla (3.02 ± 0.57 mg/ml) while it was the lowest in C. carpio (1.80 ± 0.09). C. catla contained the highest molecular weight proteins (100 kDa) while C. carpio has one unique protein band of 14.13 kDa not present in any other species in current setup.
In the 5th experiment, the lernaea were observed in the month of June to August. Lernaeied infestation was observed in all experimental fishes except in C. carpio. After appearance of infestation fishes were treated with Thunder (DDVP- an organophasphate) to eliminate the parasite. Parasite free C. idellus, H. molitrix, L. rohita, C. mrigala, C. catla and C. carpio were collected with an average weight of 830 ± 316 g each were used for studies on whole-body amino acid composition. Triplicate samples of each species were over dried after evacuating their gut contents. Dried samples were then finely powdered, sieved and vacuum hydrolyzed in 2 ml of 6 N HCl at 1lO°C for 24 hours. Total amino acid composition was determined by o-phthaldialdehyde (OPA) method using an Agilent chromatograph, revers-phase high performance liquid chromatography (HPLC). The results showed that the essential amino acids (arginine, lysine, phenylalanine, tyrosine, histidine and leucine) play a major role in the immune system. It is revealed that amino acids will widely become cost-effective neutraceuticals for improving health and preventing infectious disease in animals. C. carpio have no infestation due to increased numbers and concentrations of essential amino acids when compared to other species of Indian and Chinese major carps. C. catla, C. idella and H. molitrix have the lowest number and concentration of essential amino acids and hence appeared more susceptible to lernaea attack.
Finally it was concluded from the entire study that C. carpio may have high resistance for the L. cyprinaceaea as compared to the other experimental fishes. It possesses higher values for Ig M-immunoglobulin as compared to C. catla that indicated its high immunity against the parasite. Similarly C. carpio has maximum number of granulocytes (WBCs, esinophils, basophils and lymphocytes) that may support the fish against the parasitic attack. SDS-PAGE analysis of mucus revealed that C. carpio has one unique protein band of 14.13 kDa not present in any other species in current setup. This protein band may indicate the presence of lysozyme enzyme that actively participates against the invading pathogen. Essential and non-essential amino acids concentrations were also higher in the C. carpio that play a vital role in immunity especially arginine, lysine, phenylalanine, tyrosine, histidine, leucine, glutamic acid and aspartic acids.
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Effect Of Different Feed Ingredients On Growth, Hematology And Vital Organs In Juvenile Labeo Rohita
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Publisher: 2013 Dissertation note: This 9-month study extending from March 1, to November, 30, 2012 was conducted to find out the effect of different feed ingredients on growth, haematology and vital organs in juvenile Labeo rohita. The experiment was performed to find out the cost-effective substitutes of fishmeal and their effect on growth, digestive enzymes activity, blood profile, histology of intestine and flesh quality was monitored. To obtain the said objectives the experimental fish, Labeo rohita was subjected through three different research trials. i. A 3-month research trial was conducted to evaluate the effect of different plant/animal origin feed ingredients on growth, feed conversion ratio (FCR) and survival of fingerling Labeo rohita. Fish was fed on fish meal, guar meal, corn gluten meal (30%), soybean meal, sunflower meal, rice polish, cotton seed meal, canola meal and rape seed meal individually. Statistical analysis revealed significant differences (P?0.05) in growth, average weight gain, average length increase and specific growth rate among various ingredients. The highest average weight gain 27.162±6.950g and average length increase 6.153±0.833cm was observed in fish fed on guar meal while same was lowest 5.327±1.067g and 1.858±0.137cm, respectively in fish fed on corn gluten. However, fish showed better FCR values (2.01±0.08) when fed on guar meal while the FCR was very poor (9.57±48) for corn gluten (30%) fed group. The survival rate was highest (100%) for soybean meal fed group and lowest (70%) in canola and rapeseed meal fed group. ii. During second 3-month feeding trial, the effectiveness of individual feed ingredient from either plant or animal origin on growth, body composition, enzymes activity, haematology, histology and flesh quality of Labeo rohita was observed. The experiment was conducted in ten fiber glass tanks having size 12 ft x 4ft x 3 ft (length x width x depth). Single ingredient was considered as an independent treatment, hence guar meal, soybean meal, cotton seed meal and canola meal were considered as an independent treatment and fishmeal which was considered as a superior ingredient due to its ideal nutrient balance served as control. Ten juvenile Labeo rohita having an average weight of 200±2.33 g were harvested indiscriminately from the bulk and stocked in each fiberglass tank. Two tanks were randomly allotted to each treatment and control. Each group received uniform ration @ 4% of total fish biomass twice a day. Results revealed significant differences (P?0.05) in growth, FCR and specific growth rates among treatments. Weight gain was the highest in guar meal fed fish while the lowest on fish meal. Body composition of fish showed slight variations in fat contents with no differences in other nutrients though chemical composition of individual ingredient varies a lot. Minerals specifically Na, Ca, Fe, Zn, and Cu significantly differed (P?0.05) among treatments which might be linked with their variable release in digestive system of fish in the presence of various anti-nutritional factors. For different feed ingredients protease activity varied significantly (P<0.05) between anterior and posterior part of the intestine and also that of whole intestine when compared among various treatment groups. While amylase activity differed significantly when enzyme activity compared from the homogenate of whole intestine but not when compared partly. WBC, RBC, Hct, HB, PROT, ALB and GLOB showed significant (P<0.05) differences for blood samples of the fish fed with different feed ingredients while values of MCV, MCH, MCHC and ESR remained uniform. The feed ingredients differently affected the liver and intestinal cells. No difference was observed when fried fish fed on different ingredients were compared among each other indicating that ingredients with nominal variations in chemical composition do not leave much after effects on fish flesh. iii. Third 3-month trial was conducted to evaluate the effect of plant-animal feed and/or plant by-product based feed on growth, body composition, enzymes activity, haematology, histology and flesh quality of Labeo rohita. Fish fed on rice polish alone served as control (T0). Previously selected potential fish feed ingredients were grouped together with two ingredients in each isocaloric test diet which served as an independent trial during these studies. Group 1(T1) contained guar meal and canola meal, group 2(T2) soybean meal and cotton seed meal, group 3(T3) guar meal and cotton seed meal, group 4(T4) soybean meal and canola meal and group 5(T5) fishmeal and canola meal. Each group including control had two replicates. 12 earthen ponds with uniform area of 0.03 ha each, were randomly stocked with 100 fish (average weight 200±4.43g) in each following standard stocking protocols. All the 12 ponds were then randomly allotted to individual treatment including control group. Experimental fish were fed @ 4% of their wet biomass twice a day except Sundays which was kept open providing fish an opportunity to clean left over feed from the previous day. Better growth rate, food conversion ratio (FCR) and specific growth rate (SGR) in T3 than rest of the treatments including control suggest that guar meal and cotton seed meal is much better option to include in future feed formulations for maximum performance and minimum feed wastage. This preposition will minimize feed providing cleaner and healthy environment to fish ultimately enhancing stocking rate and fish production. Proximate analysis of dried and ground fish samples showed higher protein values in T4, fat in T2, moisture contents in control, dry matter in T1 and ash in T5. Mineral composition of Labeo rohita showed statistically significant (P ? 0.05) differences in Na, Ca, Fe, Zn and Cu content. Amylase concentration showed non-significant differences in anterior, posterior parts and the whole intestine in all the treatment and control ponds except T5 while protease concentrations were statistically significant (?0.05) in anterior and posterior part within the same group as well as among various groups. Enzymatic activity in whole intestine also varied significantly when compared among groups. Haematological parameters viz. WBC, RBC, ALB, GLOB and PROT differed significantly (?0.05) among all the treatments. Disrupted hepatic cords and hepatocytes showing pyknotic nucleus were observed in T1, moderate infiltration of fat vacuoles in T2 and, T4 caused vacuolar and hepatic cord degeneration while fish from T0 were subjected to severe vacuolation in hepatocytes. Non-significant differences in flavor, juiciness, and oiliness of fried fish from all the treatments and control ponds indicated that the sensory attributes of fish flesh were not affected by feeding fish with blend of various ingredients. It is concluded that the response of body organs varies with varying feed stuffs and the feed items have pronounced effect on enzymatic activities, hematological and histological parameters in juvenile Labeo rohita. During present study fish showed comparatively better growth when fed with guar meal as a single feed ingredient or combined with cotton seed meal than the rest of feed ingredients either offered individually or in combinations. The study provides base line information and will help aquaculture nutritionists to formulate cost-effective feeds.
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