T4 Fish Research Articles

Growth and survival assessment from African lungfish (Clarias gariepinus) and its hybrid with two species of heterobranchus

Obtaining good quality and quantity of fish seeds for increasing fish production is a major quest by fish farmers. This study examined the growth responses and survival of Clarias gariepinus and two species of heterobranchus. One thousand five hundred (1500) fry (28-day after hatched) were randomly selected from each of the three crosses of Clarias gariepinus (T1), C. gariepinus x Heterobranchus longifilis (T2) and C. gariepinus x Heterobranchus bidorsalis (T3) broodstocks. They were stocked separately in triplicate at a stocking rate of 500 fish per replicate and reared for 90 days. The data were analysed for significant differences (P<0.05) by Analysis of Variance (ANOVA). There was no significant difference in the growth parameters but fish in T3 had the highest value of mean weight gain while T1 had the least. No significant difference (p>0.05) was observed in the body weight gains from day 40 to day 90 except at day 70 where T3 had the highest weight gain (18.97 g) which was significantly different (p<0.05) to the value recorded in T1 (18.20 g) but not significantly different (p>0.05) to the value recorded in T3 (18.97 g). The results of length increment showed that the growth pattern from day 0 to day 80 were similar. A little difference was observed at day 90 with T3 >T2>T1. The fish in T1 (Clarias gariepinus) had the highest significant percentage survival (89.60%). The results of water quality parameters showed that the mean temperature was 28oC, pH 6.8, dissolved oxygen 5.6 mg/l and turbidity 5.45 NYU. The culture of C. gariepinus by farmers will improve their output and consequentially increase in profit.Keywords: aquaculture; fish breeding; hybrids; weight gain

An approach to optimizing dietary protein to growth and body composition in walking catfish, Clarias batrachus (Linneaeus, 1758).

Clarias batrachus is a commercially important food fish. In the present study, effect of varying dietary protein levels was evaluated on the survival, growth parameters and proximate composition of C. batrachus. Diets comprising 25%, 30%, 35%, 40%, 45%, and 50% crude protein (CP) were supplied to fish in T1, T2, T3, T4, T5, and T6, respectively, at the rate of 5% of fish body weight for the entire 90 days, twice daily. Size of each stocked C. batrachus was recorded after 15 days. Results revealed 100% survival rate of C. batrachus in all treatments. Significantly highest (P<0.001) mean value of weight gain (g/fish), percent weight gain, daily growth rate, specific growth rate and protein efficiency ratio (PER) in C. batrachus were recorded, reared in T4 by feeding 40% CP in diet. The best FCR value (1.90±0.02) for C. batrachus was obtained in T4 by feeding 40%CP in diet. Mean value of water, ash, fat and protein contents (wet mass) were ranged 74.10-79.23%, 3.12-4.68%, 3.90-4.43% and 13.09-16.79% for C. batrachus in the studied treatment groups. Water content (%) was found significantly (P<0.05) higher in the body of C. batrachus for T1, T2, T3 and T6 than for T4 and T5. Ash was found significantly (P<0.05) higher in the fish reared in T4 and T5. Fat content in the wet body mass of C. batrachus was found significantly higher in T4 and T1. While, significant higher (P<0.05) values of mean protein content was noted in C. batrachus reared in T4 and T5. Body composition of C. batrachus was also categorically affected by body size, however, condition factor showed non-significant correlation in most of the relationships in the present study. Overall, results indicated that feeding appropriate diet (containing 40% CP) to the fish resulted good growth performance, lower FCR and higher protein content in the fish. Present study provides valuable knowledge of optimal dietary protein level in C. batrachus which will help in commercial success of aquaculture.

Specific Growth Rate (SGR) in Different Stages of Tilapia (Oreochromis niloticus) Production Cycle in Cemented Tank Based Semi-Intensive Aquaculture System

Traditional assessment of specific growth rate (SGR) using the data of the beginning and the end of aquaculture production cycle, avoiding intermediary data, is criticized as misleading way by the scholars. However, by knowing SGR in different stages of fish growth, the utilization of feed by fish can be well known. The study was conducted with aim to assess SGR of Tilapia in six concrete tanks for 90 days from 8th May to 10th August, 2017. Tilapia (Oreochromis niloticus) fry was released at the rate of 4 fry per tank equivalent to the stocking density of 160 fishes/decimal as of the semi-intensive aquaculture system. Sinking and floating feeds were used for feeding the fish in T1 and T2, respectively with three replications for each treatment. During the experimental period, feed was given at the rate of 20%, 15% and 10% of the body weight in 1st, 2nd and 3rd month, respectively. Moreover, aeration facilities were installed for 24 hours using air stone aerator. The weight of fish was recorded using digital balance in 3 days interval to measure SGR. The water quality parameters i.e., temperature and dissolved oxygen (DO) were recorded twice daily. The weight gains of fish were 49.90±2.40 g and 63.12±4.97g for T1 and T2, respectively. The mean percent weight gain of Tilapia was higher in T2 (747±0.00 g) than T1 (253.51±0.00 g). Feed conversion ratio (FCR) in T1 and T2 were 1.70±0.07 and 2.53±0.20, respectively. Considering the data at the beginning and the end of the production cycle, the SGR (% per day) of Tilapia in T1 and T2 were 6.27±3.27 and 6.26±3.83, respectively. The SGR for floating feed was higher at the initial stage of production cycle and lower in the later stages. For sinking feed, SGR was almost static from the beginning to the end. The higher FCR in T2 correlated with the lower SGR in the later stage of the culture period. This confirmed that farmers using floating feed with pre-determined amount of feeding ration, waste the expensive feed and money. Higher total production was obtained in T2 (830.96 g) than T1 (610 g) with 100% survival in both treatments. Therefore, determining SGR in a specific interval, at least 15 days interval, might be the efficient feeding practice of Tilapia farmers.

Efficacy of an Insect-Based Diet with Addition of Probiotics on Growth, Proximate Composition, Enzymatic Efficiency, and Immune Response of Nile Tilapia

Insects are potential alternative protein sources to replace fish meal (FM) in aqua feed. The role of insect species as replacements in the aqua industry has been a hot debate in the current era. The present study evaluated the influence of FM replacement with insect-based meals (black soldier fly (BSF) and maggot fly) in the feed of Nile tilapia. Eight diets with graded replacement levels of FM were formulated along with basal diet as T0 (control group having basal diet), T1 (25% maggot meal (MM) with 2% probiotics), T2 (50% MM + 2% probiotics), T3 (75% MM + 2% probiotics), T4 (100% MM + 2% probiotics), T5 (25% BSF meal (BSFM) + 2% probiotics), T6 (50% BSFM + 2% probiotics), T7 (75% BSFM + 2% probiotics), and T8 (100% BSFM + 2% probiotics). Fish having an initial body weight of 7 g were fed on formulated feed for 16 weeks. Growth parameters, including weight, length, feed conversion ratio, specific growth rate, and survival rate, were observed weekly, and significant ( p &lt; 0.05 ) results were attained up to 75% replacement level with no adverse effect on growth. However, at 100% replacement of FM, fish growth was retarded. Maximum survival rate was observed in T1 and T5 and minimal in T4 and T8. Body composition, including crude protein, fat, moisture, and ash, showed significant ( p &lt; 0.05 ) results. Similarly, digestive enzyme (protease, lipase, and amylase) activity was measured at the end of the trial. Fish in T1 and T5 groups had the highest digestive enzyme activity, which slightly decreased with the inclusion of insect-based meals and probiotics. Statistically significant ( p &lt; 0.05 ) results were observed for antioxidant enzyme activity in catalase, glutathione peroxidase, and superoxide dismutase. The most vigorous immune response was shown in T1 and T5, with higher white blood cells and high levels of IgM. The present research showed that FM could be replaced with BSF meal and MM with probiotics up to 50% for better fish health performance; however, 75% replaced FM without compromising growth and health status.

Integrated farming of stinging catfish (Heteropneustes fossilis) and rabbit (Oryctolagus cuniculus) in farmer’s pond

A study was carried out to evaluate the growth and production performances of stinging catfish (Heteropneustes fossilis) and rabbit (Oryctolagus cuniculus) under two treatments such as T1 (shing-rabbit integrated system) and T2 (shing monoculture) in farmers’ pond. Twelve ponds from two villages such as Sutiakhali and Salakandi under Mymensingh sadar upazila were selected for the study. The average pond size was 5.5±0.23decimal with a stocking density of 600 shing dec-1. The ponds were only fertilized with rabbit dung except at the time of pond preparationat a rate of 1 kg dec-1. Various environmental parameters such as temperature (oC), transparency (cm), PH, dissolve oxygen (mg L-1), PO4-P (mg L-1), NO3-N (mg L-1), NO2-N (mg L-1), NH3-N (mg L-1), chlorophyll and alkalinity (mg L-1) were monitored once in a week. The parameters were found to vary little from pond to pond and most of the parameters were within the suitable range for freshwater aquaculture in Bangladesh. The highest survival rate of fish was 95.36 ± 0.15 % in treatment T1 and the lowest was 90.39 ± 0.10 % in treatment T2. The survival rates of fish were not significantly different among the treatments (P &gt; 0.05). The production of fish in T1 and T2 treatment was 25.36 and 20.43 kg dec-1, respectively. Daily growth of shing in two treatments were 1.95 ± 0.01 and 1.88 ± 0.01 % respectively. The study revealed that integrated shing-rabbit would be highly profitable using improve extensive culture system in the rural household ponds through effectively reducing the use of pond fertilizer and fish feeding cost.&#x0D;

ROLE OF VITAMIN C AND E ON GENOTOXICITY, HEMATOLOGICAL AND BIOCHEMICAL INVESTIGATION IN CYPRINUS CARPIO L. FOLLOWING ZINC OXIDE NANOPARTICLES EXPOSURE

This study was aimed to evaluate the role of vitamins C and E on genotoxicity, biochemical and hematological indices in common carp, Cyprinus carpio following zinc oxide nanoparticles exposure. Zinc oxide nanoparticles were synthesized (size was &lt; 34nm) and characterized using Fourier Transform Infrared Spectra (FTIR) and X-Ray Diffraction (XRD) analysis. About 120 common carp (weight 20.0-32.0 g) were randomly divided into 12 tanks at rate of 10 fish/tank (two (replicates/treatment); fish were fed diet as follows: Control (C) were fed basal diet; T1 fish were fed basal diet mixed with vitamins C and E (400 mg/kg); T2 and T3 fish were fed basal diet mixed with 10%and 15% ZnONPs respectively; T4 and T5 fish were fed basal diet mixed with ZnONPs 10% and 15% plus vitamins C and E (400 mg/kg dw) respectively. Post 40 d feeding trail, variable changes were registered in blood indices (“Hb content, PCV%, WBCs and RBCs numbers”) in all treated groups compared to C and T1 groups. The highest DNA damage (% tail DNA using Comet assay) was seen in T2 and T3 which asserted highly significant increased (P≤0.01) compared to C and to treated groups. As well as, glutathione peroxidase (GPx) activity exhibited highly significant increase (P≤0.01) in T2 and T3 groups relative to C, T4, T1, T5 respectively. This investigation clearly proved that sub-lethal doses (10 and 15% in diet) of ZnONPs were able to induce an oxidative stress in carp fish as reflected by significantly increase of DNA damage to erythrocytes and “the combination of vitamins C and E was able to alleviate the oxidative stress generated due to exposure to ZnONPs.”

Evaluating the inclusion of phytase sources to phosphorus-free diets for GIFT tilapia (Oreochromis niloticus): Growth performance, intestinal morphometry, immune-antioxidant responses, and phosphorus utilization

The current study aimed at evaluating the growth performance, phosphorus (P) retention, and welfare status of GIFT strain of Nile tilapia (Oreochromis niloticus) fed on P-free diets containing fungal phytase (FPhyt) and/or a novel hybrid bacterial phytase (HB-Phyt). The control reference diet (T1) was supplemented with dicalcium phosphate (DCP; 8.7 g total P/kg). Other five low-P (with no DCP; 5.9 g total P/kg feed) diets were supplemented with 500, 1000 FTU/g of FPhyt (T2-T3) or 500, 1000 FTU/g of HB-Phyt (T4 – T5), while T6 contained 1000 and 1000 FTU/g of both phytase sources. Each diet was allocated randomly to three 100-L tanks stocked with GIFT tilapia (n = 15 fish per tank, initial mean weight, 2.38 ± 0.22 g). Fish were fed on experimental diets up to satiation thrice a day for 60 days. Fish in T1, T3, T5, and T6 recorded highest growth performance; meanwhile, highest values of villi length/width and absorption area were observed in T3, T5, and T6 fish groups as compared with other groups. Highest values of hematological indices (red blood cell, hemoglobin, packed cell volume, white blood cell, and lymphocytes %) and immune-antioxidant biomarkers (superoxide dismutase, catalase, lysozyme, and respiratory burst activity) were highest in the case of fish in T3, T5, and T6 with no significant difference among them. Meanwhile, feeding fish on diets with 500 FPhytase (T2) or 500HB-Phyt (T4) showed lowest values of immune-antioxidant indices accompanied with highest value of malondialdehyde as compared with other treatments. Compared with other treatments, highest values of bone-P were observed in T3, T5, and T6, while highest whole-body P values were detected in T5 and T6 only, with no significant difference among them. The present study revealed much lower feed input per unit production accompanied with higher return on investment in GIFT fed on diets supplemented with 500 FTU/g of HB-Phyt than 1000 FTU/g of either FPhyt or HB-Phyt. Hence, the present study showed that the dietary inorganic P could be compensated by adding 1000 FTU/g of either FPhyt or HB-Phyt to fish diets. The growth and immune-antioxidant indices in fish fed with HB-Phyt were superior to FPhyt treatments. No synergetic effects of using both of FPhyt and HB-Phyt were detected in this study.

Potential protective effects of thyme (Thymus vulgaris) essential oil on growth, hematology, immune responses, and antioxidant status of Oncorhynchus mykiss exposed to malathion

Abstract As an abundant source of antioxidants and diet flavor enhancers, the plant essential oils can have positive effects on fish growth, and resistance against environmental stressors. In this study, garden thyme (Thymus vulgaris) essential oil (TEO) was used in the diet of rainbow trout, Oncorhynchus mykiss, to evaluate its protective effect against malathion pesticide exposure. Tested fish (19.99±0.01 g) were divided into six groups (three replicates), namely: T1: control diet; T2: control diet + 0.025 mg L−1 malathion; T3: control diet + 0.075 mg L−1 malathion; T4: control diet + 1% TEO; T5: control diet + 0.025 mg L−1 malathion + 1% TEO and T6: control diet + 0.075 mg L−1 malathion + 1% TEO. After 21 days, T4 fish had the highest final body weight (FW), weight gain (WG), specific growth rate (SGR), and the lowest feed conversion ratio (FCR) among experimental treatments (P&lt;0.05). The blood parameters including the red blood cells (RBC), white blood cell count (WBC), hematocrit (Hct), and hemoglobin (Hb) values were the highest in T4 treatment, displaying a significant difference with T1 treatment (P&lt;0.05). Fish in the T4 groups had the highest total protein (TP) and albumin (ALB), while fish of T3 showed the lowest levels of these parameters (P&lt;0.05) and also had the highest level of triglycerides (TRG), cholesterol (CHOL), lactate dehydrogenase (LDH), and urea (Ur). Alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) enzymes recorded the lowest levels in T4 treatment, which showed a significant difference with T1 group. The catalase (CAT) and superoxide dismutase (SOD) showed the highest activities in T4 treatment, while the lowest SOD and the highest malondialdehyde (MDA) levels occurred in T3 group (P&lt;0.05). Total immunoglobulin (total Ig) level, alternative complement (ACH50) and lysozyme in the serum and skin mucus of T4 treatment of rainbow trout showed the highest activities with a significant difference from groups (P&lt;0.05). From the results of the present study, it can be concluded that 1% of T. vulgaris as a supplement to the diet of rainbow trout can stimulate and improve the immune system of the fish. TEO can have a protective effect against unfavorable effects of malathion and improves the growth of the fish.

Lactobacillus casei (IBRC-M 10,711) ameliorates the growth retardation, oxidative stress, and Immunosuppression induced by malathion toxicity in goldfish (Carassius auratus)

Abstract Probiotics can functionally improve fish wellbeing and are suggested as antioxidative agents to protect fish from xenobiotics toxicity. Herein, dietary Lactobacillus casei (IBRC-M 10,711) was included in the diets of goldfish (Carassius auratus) to protect against malathion toxicity. Fish (12.47 ± 0.06 g) were randomly allocated to six groups (triplicates), as follows: T1) control; T2) fish exposed to 50% of malathion 96 h LC50; T3) L. casei at 106 CFU/g diet; T4) L. casei at 107 CFU/g diet; T5) fish exposed to 50% of malathion 96 h LC50 + L. casei at 106 CFU/g diet; T6) fish exposed to 50% of malathion 96 h LC50 + L. casei at 107 CFU/g diet. After 60 days, goldfish fed T4 had the highest final body weight (FBW), weight gain (WG), and specific growth rate (SGR), and the lowest feed conversion ratio (FCR) among the groups (P &lt; 0.05). However, the T2 group showed lower FBW, WG, and SGR and higher FCR than fish in T1 (P &lt; 0.05). Fish in the T4 group had the highest blood total proteins, albumin, and globulin, while fish in T2 had the lowest levels (P &lt; 0.05). Fish in the group T2 had the highest triglycerides, cholesterol, cortisol, lactate dehydrogenase (LDH), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) levels in the blood, while fish fed T4 had the lowest values (P &lt; 0.05). The superoxide dismutase (SOD) and catalase (CAT) showed the highest activities in T3 and T4 groups, and the lowest SOD was seen in the T2 group, whereas the lowest CAT was seen in the T2, T5, and T6 groups (P &lt; 0.05). Fish in the T5 and T6 groups had higher glutathione peroxidase (GSH-Px) activities than fish in T1 and T2 groups but T3 and T4 groups showed the highest values (P &lt; 0.05). T2 group had the highest malondialdehyde (MDA) level, while T3 and T4 groups had the lowest MDA level (P &lt; 0.05). Blood immunoglobulin (Ig) and lysozyme activity were significantly higher in T3 and T4 groups and lower in the T2 group than in the control (P &lt; 0.05). The alternative complement pathway (ACH50) was significantly higher in T2, T3, T4, T5, and T6 groups than in the T1 group (P &lt; 0.05). Skin mucus Ig was significantly higher in T3 and T4 groups and lower in the T2 group than in the control (P &lt; 0.05). The highest lysozyme activity, protease, and ACH50 in the skin mucus samples were in the T4 group, while the lowest values were in the T2 group (P &lt; 0.05). In conclusion, dietary L. casei protects goldfish from malathion-induced growth retardation, oxidative stress, and immunosuppression.

Simplified Hatchery Protocols for Culture of Orange-Spotted Spinefoot Siganus guttatus (Bloch, 1787) in Palawan, Philippines

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.

Effect of feeding frequency on the growth of GIFT (Oreochromis niloticus)

The experiment was conducted at Sharnalata Agro Fisheries Limited, Radhakanai, Fulbaria, Mymensingh by using three treatments (T1, T2, T3) and each having 2 replications for a period of 35 days in hapa system to see the growth performance of tilapia. In T1 - fish fed four times daily, T2- fed three times daily and T3 - fed two times daily. GIFT fingerlings weighing 30 ± 3.80 g were reared by feeding a formulated diet containing 32% protein (Mega 301p) feeding at the rate of 10% of the body weight of fish for the first 3 weeks and then it was adjusted to 8% of the body weight for the next 2 weeks. It was found that mean weight gain were 105.12 ± 4.60, 105.8 ± 5.23 and 108.2 ± 4.86 g respectively. The mean weight gain was not significantly different (p>0.05) among three treatments but a bit higher growth was found in T3 compared to T1 and T2. The SGR values of the experimental fish in T1, T2 and T3 were 4.32 ± 0.32, 4.34 ± 0.30 and 4.38 ± 0.28 respectively. SGR (%/day) was highest in T3 and FCR was lowest as expected. GIFT reared in hapa showed better growth performance by feeding two times daily. Many previous researches showed that maximum growth rate was obtained by feeding fish three times a day. Therefore, it can be concluded that the ambiguity of the present results with the previous works (feeding three times provided better growth) can be resolved by conducting experiments under control temperature conditions and by subsequently extrapolating that results in farm conditions especially during best growing season of the fish (June-July).

Dietary supplementation of garlic, propolis, and wakame improves recuperation in cadmium exposed Japanese medaka fish (Oryzias latipes)

Cadmium (Cd) toxic effects can overwhelm endogenous antioxidants and affect recuperation in fish. Thus, this study assessed antioxidative properties and ameliorating potentials of dietary supplemented garlic (D1), propolis (D2), and wakame (D3) on i) Cd bioconcentration, and ii) Cd induced toxicity during recuperation in Cd exposed Japanese medaka. In a 21-day exposure, control (0.0 mg Cd/L in water—C1) or Cd-treatment (0.3 mg Cd/L in water—T1) fish were fed medaka diets. Surviving fish in T1 were further depurated for 21-days and fed D1, D2, D3, or medaka diet (C2). Gill, liver, and muscle tissues were assessed weekly for Cd bioconcentration, metallothionein, (MT), superoxide dismutase (SOD), total glutathione (GSH), and lipid peroxidation (LPO). Results showed reduced antioxidant activity by significantly increasing tissue Cd and LPO, and significantly reducing SOD activity and GSH content in gill and muscle upon Cd exposure. In contrast, D1, D2, and D3 diets significantly reduced tissue Cd and LPO, while increasing contents of MT and GSH, and SOD activity, significantly. Other condition indices in D1, D2 and D3 groups were also significantly higher than those in C2 groups. In conclusion, dietary supplementation significantly increased recuperation and tissue functions in fish, in the order D1 > D2 > D3> C2.

Growth and Economics of Silver Barb (Barbonymus gonionotus) in Rice-fish-vegetable Integrated Culture System at Different Stocking Densities in a Rainfed Arid Zone

Sustainable integrated farming involving the combination of rice-fish-vegetables requires advanced technology to be adopted in crop production in arid zones characterized by red or yellow soil. In the present study, we used suitable and varying stocking densities of Silver barb (Barbonemus gonionotus) and evaluated in a structured production and economic framework under four treatments (T1, T2, T3, and T4) assigned with a stocking density of 10, 20, 30 and 40 fish/decimal, respectively. We used standard methods of water, soil, and plankton monitoring of the rice field. The study showed that lower stocking density provided the fish with more spaces and less competition for food resulting in higher growth performance in T1 compared to other treatments. Although stocking density did not show any significant (P>0.05) effect in rice, straw and vegetable production in all the treatments, the highest rice and straw production at T4 could be ascribed to the improvement in soil fertility by the accumulation of fish excreta and subsequent release of nutrients from the soil by the higher number of fish in that treatment. The best fitted polynomial regression line obtained between gross yield and net yield with different stocking densities of Silver barb described an inevitable fluctuation in net yield of fish with increasing stocking density. Despite the stable growth performance of fish in T1, a combined effect of lower total input cost, higher yield of fish and rice, and economical vegetable production, T2 showed a significantly (P<0.05) higher total return. Furthermore, the benefit-cost ratio (BCR) for rice-fish-vegetables integrated culture system in the rain-fed rice field was also high. In conclusion, this study revealed that maintaining a stocking density of 20 fish/decimal was economically profitable for rice-fish-vegetables integrated culture systems in arid zones on a global scale.

Is a taurine supplement necessary in fishmeal-based feeds for juvenile European sea bass (Dicentrarchus labrax)?

The effect of taurine supplementation of fishmeal-based feeds for juvenile European sea bass (Dicentrarchus labrax) was investigated. Fish (initial weight ca. 5 g) were reared for 90 days in 12 concrete tanks (1 m3), with 50 fish in each tank. Four feeds (44% crude protein (CP) and 17% lipids (L)) containing 0 (control (CTRL)), 0.4 (T4), 0.7 (T7) and 1.0 (T10) % taurine were prepared and were fed to apparent visual satiation to triplicate groups of fish. The effects on fish growth, feed utilization, proximate chemical composition, haematology, immune biomarkers and muscle morphometry were examined. An increase in the dietary taurine incorporation resulted in progressive increases in the growth metrics, with the highest values being observed for fish receiving the T10 feed (weight gain 22 vs 18 g/fish in CTRL; protein productive value 31 vs 28% in CTRL). Taurine addition at all levels significantly increased the fish protein percentage, but the percentage lipid was reduced significantly in T4 fish only (7.8% compared with 9.4% in CTRL fish). Taurine supplementation resulted in elevated blood lymphocyte and monocyte counts and increased serum phagocytic and lysozyme activities. Taurine addition at 1% (T10 feed), the suggested level to boost growth, altered the dorsal muscle cellularity and myofibril ultrastructure, suggesting enhanced muscle function and firmness in comparison with that of the fish given the CTRL feed.

Effect of Different Water Qualities On Clarias Gariepinus Growth And Survival

Growth and survival of Clarias gariepinus in different water qualities were investigated. Initially, water of equal quality was used for the experiment, later the quality of water varies due to period of water change, (daily-T4, weekly-T3, bi-weekly-T2 and monthly-T1). Physico-chemical parameters were analyzed. Two hundred and forty (240) seven weeks old fingerlings of C. gariepinus were randomly distributed into 12 plastic tanks. Poor growth of C. gariepinus was observed in the treatment tanks (T1, T2 and T3), compared with growth of fish in the control (T4) which was progressive as indicated by the higher value of condition factor. Treatment tanks had significantly (P &lt; 0.05) higher EC, TDS, Turbidity, Ammonia, Nitrate and Nitrite and significantly (P &lt; 0.05) lower DO than culture water in control container. Slight growth was recorded for fish in T1 and T2 until the second week when drop in fish weight was observed. This study has shown that poor water quality can reduce growth rate and survival of C. gariepinus.

Effect of Adding Microalgae Chlorella sp. on Some Biological Parameters and Proximate Analysis of Common Carp Cyprinus Carpio L.

Backgrounds: Chlorella is used popularly as dietary supplements. Various studies and researches have been done regarding the intervention of microalgae as foods since a long time ago. And, it is found that Chlorella have potential health benefits, in terms of their protein and antioxidant content. Thus, with an objective of formulating nutritional supplements, this algae are being harvested in artificial ponds on a large scale and could be used in different way such as feed supplemet or a replacement with a source of protein. Objectives: evaluate the effect of feed containing various ratios of Chlorella on some biological parameters in common carp. Methods: The experiment was conducted for 105 days and for these purpose 200 fingerlings common carp C. carpio L. were brought from a local aquarium fish in Iraq. Mean initial weight was 35.7g. The fish were acclimated to laboratory conditions and fed with control pellets (29% protein) prior to the feeding trials for 21 days in fish laboratory/ Dept. of Animal Sciences/ College of Agricultural Sciences/ University of Sulaimani. In T1 fish were fed a diet with 0 Chlorella gm/kg diet,while in T2, fish were fed a diet with 2.5 Chlorella gm/kg diet, T3 represents the third treatment, in which fish were fed on a diet with 5 Chlorella gm/kg diet, and in T4 fish were fed a diet with 7.5 Chlorella gm/kg diet. Results: The present study clearly showed that feeding algae as a feed additive to fish remarkably change the studied biological parameters, in Hepatosomatic index all treatments were significantly differ than the control, Spleenosomatic index the control and T4 were higher significantly than others, in Gonadosomatic index the T2 and T4 were differ significantly while T4 was significantly higher than other treatments in Kidneysomatic index. Fish weight without viscera and weight without viscera & head differ significantly among treatments with the addition of Chlorella the diet. Conclusion: Chlorella can be used as protein rich sources to replace fishmeal or as feeding additives in the diets of common carp fingerlings with different levels. Products that are safe and of good quality.

Impact of farm-made liquid organic nutrients jevamirtham and fish amino acid on growth and nutritional status in different season of Abelmoschus esculentus—a self-sustainable field trial

In organic agriculture, jeevamirtham (J) and fish amino acids (FAA) (Liquid organic nutrient bioformulations—LONBFs) were used to improve the plant growth and soil fertility. The effect of J and FAA in combination on the growth, nutritional status, and yield of plant has not been scientifically evaluated. In this study, liquid organic preparations of J and FAA were prepared and applied to okra plants individually and in combination (J + FAA). The experimental fields were designed as T1—untreated control field, T2—chemical fertilizer treated field, T3—jeevamirtham-treated field, T4—fish amino acid-treated field, and T5—mixture of jeevamirtham and fish amino acid-treated field. Microbial population and growth parameters were significantly increased in the T3, T4, and T5 fields. Higher chlorophyll, carbohydrate, and protein contents and more fruits were observed in plants from the T3, T4, and T5 fields than in plants from T2 and T1. The most favorable results were recorded in the J+FAA-treated field (T5). Results showed that LONBFs enhanced the beneficial microbial flora and fauna, higher yields, and nutritional products compared with chemical fertilizer and untreated fields. Hence, this eco-friendly LONBF could be added as an integral component to reduce the impact of chemical fertilizer in modern agriculture practice.

Effects of feeding frequency on growth performances and RNA : DNA ratio of the gangetic mystus (Mystus cavasius Hamilton, 1822) in laboratory condition

Experiments were conducted for a period of 90 days to estimate the effects of different feeding frequencies (one time per day: T1, two times per day: T2, three times per day:T3 and four times per day: T4) on growth performance of gulsha fish reared in laboratory facilities. Significantly higher condition factor was observed in T2 (1.61 ± 0.02) and lowest in T4 (1.40 ± 0.01). Significantly lowest SGR and ADG were recorded in T4 fish fed four times per day. No significant difference was obtained among different treatments for FCR and survival rate. The highest RNA : DNA ratio (0.93 ± 0.07) was observed in fish of T2 and the lowest ratio (0.57 ± 0.11) was observed in fish of T1. The results of the present study suggest that in laboratory rearing two meals per day could be supplied for better growth performances as per indication of condition factor and RNA:DNA ratio.&#x0D; Dhaka Univ. J. Biol. Sci. 27(1): 75-83, 2018 (January)

Comparative effect of probiotic (Saccharomyces cerevisiae), prebiotic (Fructooligosaccharide) and their combination on some blood indices in young common carp (Cyprinus carpio L.)

This study was carried out to examine the effect of Fructooligosaccharide as a source of prebiotic, and commercial dry yeast (Saccharomyces cerevisiae) as a source of probiotic and their combination in different level as a source of synbiotic. The experiment was conducted in the fish laboratory of Animal Production Department, Faculty of Agricultural Sciences of Sulaimani University. The trials lasted for three months after 21 days of adapting period 120 common carp fingerlings with an average weight of 20 ±2 gm, were used to test the effect of different levels of the Fructooligosaccharide, yeast and their combination. In T1 fish were fed a diet with 2.5 gm/kg Fructooligosaccharide, in T2, fish were fed a diet 2.5 gm/kg yeast, T3 represents the third treatment, in which fish were fed on a diet 5 gm/kg Fructooligosaccharide. While, in T4 fish were fed a diet 5 gm/kg yeast, and T5 2.5 Fructooligosaccharide: 2.5 Yeast (gm/kg), T6 was 5 Fructooligosaccharide: 5 yeast (gm/kg), T7 2.5 Fructooligosaccharide: 5 Yeast gm/kg), while T8 5 Fructooligosaccharide, 2.5 (gm/kg) Yeast. Each treatment in three replicates in which five fingerlings common carp were stocked in plastic tanks, which fed the experimental diets twice daily. Blood parameters of tested fish showed significant differences in Red blood cell count (1012 cells/l) in T5 and T7 by 1.235 and 1.260, respectively. Hemoglobin (g/dl) data were 117.000 in the fifth treatment. The mean corpuscular hemoglobin (pg/cell) was 121.400 in T2, 137.850 in T3, 121.050 in T4, and 135.300 in T6; mean corpuscular hemoglobin concentration (g/l) was 924.000, in the seventh treatment, mean corpuscular volume were (fL) 232.500 and 233.050 in T4 and T8 respectively. There were different effects of the treatment in the studied blood parameters in which the level of 2.5 g/kg in both Fructooligosaccharide and dry yeast affect significantly the Red blood cell, White blood cell and Hemoglobin.

Preliminary study on the production of common carp cultured in freshwater river cages

A preliminary study was conducted to assess the performance of the common carp, cultured in freshwater river of Brahmaputra cages at different stocking densities during November 2011 to March 2012.The stocking densities tested were 80, 100 and 120 fish/m3. Fish were fed a 28% protein diet at the rate of 15-5% of body weight. The result of the study showed that fish in the T1 stocked at the rate of 80 fish/m3 resulted the best individual weight followed by T2 and T3. The productions of fish in T1, T2 and T3 were 22.33±1.20, 19.00±0.58 and 18.00±1.15 kg/m3, respectively. The results of the present study indicated that the best individual growth and production of common carp was obtained at a density of 80 fish/m3. The results also showed that the individual mean harvesting weights were negatively correlated with stocking density. Therefore, the stocking density of 80 fish/m3 is considered optimum for the rearing phase. DOI: http://dx.doi.org/10.3329/ijarit.v4i1.21086 Int. J. Agril. Res. Innov. &amp; Tech. 4 (1): 24-27, June, 2014