Growth performance, recovery rate and fish yield of GIFT strain at various water depths under rice-fish culture systems

Effect of water depth on recovery rate, growth performance and fish yield of GIFT in the rice-fish production systems was studies in experimental plots of 123 m2 with a pond refuge of I meter deep which covered 10% of the total land area. Mortality rate of fish was very low ranging from 0.81-1.63%. However, at harvest, recovery rate ranged from 76.69-82.93% with the highest recovery at 11-15 em of water depth. Significantly the highest absolute growth (99.97) and specific growth rate (2.42%) were found at 21-25 cm water depth. The same treatment also produced significantly higher fish yield (909.76 kg/ha) although statistically similar to the fish yield (862.60 kg/ha) obtained at ll-15 em of water depth. Results also suggested that higher water depth can produce bigger fish but no significant effects of water depth was found on fish yield in the treatments 11-15 cm and 21-25 cm water depths of this experiment.

Diel feeding patterns, rate of gastric evacuation and foods of Indian sandwhiting, Sillago sihama in Mulki estuary, west coast of India

Diel feeding chronology of sandwhiting, Sillago sihama was examined from stomach collections taken during the months of April, July and December'99 in Mulki estuary along Dakshina Kannada coast, India. Significant differences in mean stomach content weight were found between several consecutive 3 hour periods with peak fullness occurring in early morning and evening hours. The rate of gastric evacuation of natural food (crustacea, polychaetes and fish) was measured in the field was best described by an exponential model, with an estimated evacuation time of 8.0 h at a temperature of 28.5 ± 1.2°C. Stomach content analysis indicated that this species is a carnivore on a wide range of benthic, epibenthic and planktonic prey. The principal food items of S. sihama were crustaceans, polychaetes and fish. Fishes less than 100 mm TL preferred mainly crustaceans while larger ones depends on polychaetes, crustaceans and fish. The feeding activity of S. sihama was influenced by tidal cycle.

Cumulative inbreeding rate in hatchery-reared indian major carps of Karnataka and Maharashtra states

The state fisheries department hatcheries are the major suppliers of seed to the farmers in Karnataka and Maharashtra. The brood stocks of these hatcheries are genetically closed units. In the present study, effective population size and cumulative inbreeding rates were estimated. The cumulative inbreeding rates ranged from 2.69 to 13.75, 8.63 to 15.21 and 3.02 to 5.88 per cent for catla, mrigal and rohu, respectively, in Karnataka state hatcheries. In Maharashtra, the cumulative inbreeding rates for catla ranged from 7.81 to 39.34 per cent and it was 5.84 to 14.09 and 2.46 to 10.20 per cent for mrigal and rohu, respectively. To estimate the inbreeding rates in future generations, predictive models were developed using linear regression, and polynomial and power equations separately for each hatchery. Their multiple correlation and standard errors suggested that simple linear regression can predict the future inbreeding rate efficiently.

Mapping of the Indian fisheries growth rate and fish consumption through GIS

In the present study, Indian fisheries growth rate and fish consumption have been analyzed through GIS mapping. The analyses were based on the state-level fisheries data of India collected from the secondary sources. Accordingly, the paper contains one thematic map containing two layers. To achieve this, all the data have been brought into a tabular form through Microsoft Excel and then joined to Map Info Professional Version 8.0 GIS software with digitized map of India for further analysis to generate thematic maps. In this thematic map, the first Jayer represents the growth-rate of fish production for the period 1990-2004 and the second layer represents fish consumption for the year 2003. The thematic map represented in graphic form presents inland, marine and total growth rates, and also the rural and urban fish consumption at the state levels. This study will be useful to fish traders, planners, researchers and administrators in fisheries policy formulation for sustainable development.

Effect of feed quality restriction followed by realimentation on growth, nutrient utilization, biochemical changes and haematological profiles of Indian major carp, rohu (Labeo rohita H.)

To investigate the effect of protein restriction with subsequent re-alimentation on nutrient utilization, hematological and biochemical changes of Indian major carp, Rohu (Labeo rohita H.), 150 acclimatized Rohu fingerlings (average 20.74 ± 0.13 g) divided into five experimental groups (30 fingerlings in each groups with three replications with 10 fingerlings in each) for experimental trial of 90 days using completely randomized design. Control group (T sub(CPR)) was fed with feed having 30% crude protein at 3% of body weight for 90 days trial period. Other experimental groups T sub(1PR) was alternatively 3 days fed with feed having 20% CP and 30% CP at 3% of body weight, T sub(2PR) was alternatively 7 days fed with feed having 20% CP and 30% CP at 3% of body weight, T sub(3PR) was alternatively 15 days fed with feed having 20% CP and 30% CP at 3% of body weight and T sub(4PR) was alternatively 25 days fed with feed having 20% CP and 30% CP at 3% of body weight during 90 days trial period with daily ration in two equal halves at morning and afternoon. It was noticed that retention of different nutrients was almost similar among all treatment groups indicated improvement of digestibility of nutrients might not be the mechanisms for recovery growth in carps. Increased percent feed intake of body weight (hyperphagia) (4.14 ± 0.30 or 4.94 ± 0.46 and 3.33 ± 0.29), improved specific growth rate (1.86 ± 0.09 or 2.26 ± 0.05 and 1.43 ± 0.01), absolute growth rate (1.57 ± 0.08 or 1.84 ± 0.18 and 1.36 ± 0.12), protein efficiency ratio (1.19 ± 0.11 or1.16 ± 0.12 and 1.05 ± 0.09) were the important mechanism showing better performance index (21.60 ± 1.09 or 23.80 ± 0.21 and 19.45 ± 0.37) through which the experimental groups which were protein restricted and re-alimented at 3 or 7 days alternatively during 90 days trial period could able to compensate the growth retardation and to catch up the final body weight of control (128.68 ± 11.53 g/f) but other experimental groups failed to compensate during 90 days trial period. Result of the present study indicated that deprived fish i.e., fish received alternate 3 or 7 days protein restriction and re-alimentation showed recovery growth had still lower values of Hb (10.21 ± 0.02, and 9.88 ± 0.04 g/dl), hematocrit value (30.62 ± 0.05 and 26.64 ± 0.11%), total erythrocytic count (3.40 ± 0.01 and 3.29 ± 0.01 X10super(6) mm³), plasma glucose (126.93 ± 0.20 and 126.67 ± 0.05 mg/dl), total plasma lipid (1.04 ± 0.01 and 1.02 ± 0.01 g/dl) and liver glycogen (290.10 ± 0.80 and 288.99 ± 0.95 mg/kg) in comparison to control (10.56 ± 0.08 g/dl, 31.68 ± 0.24%, 3.52 ± 0.03 X10super(6) mm³, 128.23 ± 0.25 mg/dl, 1.07 ± 0.01g/dl and 292.00 ± 0.23 mg/kg) at the end of 90 days trial but total plasma protein in deprived group was compensated with advancement of trial period. All hematological and biochemical parameters studied were proportionately lowered in the experimental group got higher degree of deprivation. These findings suggested that with the increase of trial length complete compensation of hematological and biochemical profiles of rohu might be achieved. The results indicated that the implementation of alternative 7 days low and high protein diet feeding during aquaculture of carps could make economize the operation through minimizing the feed input cost.

Production of freshwater giant prawn using over-wintered juveniles for enhancement of farm income and reduction of rural poverty in Bangladesh

Freshwater giant prawn, Macrobrachium rosenbergii fry produced during late season can not withstand low temperature thus the prawn culture programme during winter is hampered. To overcome this problem, late season (August-September) prawn juveniles (0.9-6.8 g) were stocked at a density of 1.43 to 3.57/square meter in 350-476 square-meter ponds in Pabna and Mymensingh districts during October 2000 and cultured till May 2001. Monthly average water temperature during the winter months (December-February) varied from 16 to 22 °C and gradually increased to 32 °C in May. The prawn fry showed fast growth rate and attained an average weight of 60-70 g within eight months including three winter months. Growth compensation was observed during summer months. Survival rate was 60-79%. After extrapolation of the present growth rate more than 1,600 kg/ha production can be achieved in better-managed ponds. Extrapolated cost of production was Tk. 268,000 and 200,000 Tk./ha in two best ponds, sale value was Tk. 644,9146 [sic] and 528,466 and gross profit was Tk. 376,000-410,000, suggesting a higher economic feasibility of farming freshwater prawn with over-wintered juveniles.

Investigations on wooden floating materials: the loss of buoyancy under continuous immersion in water and the rate of its redemption by drying

A wooden fishing float under immersion in water for long periods is liable to absorb water, the quantity of water absorbed possibly being dependent upon the physical factors like the specific gravity and the inherent property of the material, the time of soaking and the pressure acting on it. Consequently a wooden float is likely to become heavy and loss its original buoyancy. However, when the float is removed from water and dried, the lost buoyancy is regained on complete drying. The present paper is an attempt to elucidate these two important characteristics of some of the chief wooden floating materials used on the West Coast of India.

Rate of filtration by Perna viridis pre-exposed to heavy metals

Perna viridis exposed to different concentrations of copper and zinc for varying periods and then the rate of filtration estimated under metal free culture conditions. The concentrations under which the animals were maintained before the experiments were 0.025 to 0.150 p.p.m. of zinc and 0.005 to 0.08 p.p.m. of copper.

Relationship between diet composition and growth rate of the zoeal and mysis stages of Penaeus japonicus Bate

Diets containing Chaetoceros gracilis plus Artemia nauplii artificially prepared diet, Diet-B, and two commercial feeds Tapes and mysid meals, were fed to larvae of P. japonicus. Highest survival rate was obtained when larvae were fed with Diet-B. The results show that the early larval stages of P. japonicus can be reared on artificially prepared diets. Since the chemical composition of the diet is known, it can be used as supplemental data for larval feeding development and nutritional requirement studies for the early larval stages of Penaeus japonicus and/or other penaeids. Information is tabulated on feeds and feeding rates used, composition of the artificial diet, fatty acid composition of lipids of the different diets, and of the sterols of the different diets.

Effects of dietary supplementation of commercial human probiotic and antibiotic on the growth rate and content of intestinal microflora in ornamental fishes

The effects of dietary supplementation of commercial human probiotic, Lactobacil and antibiotic, oxytetracycline on the growth, survival, disease resistance and content of intestinal microflora in two ornamental fishes, viz., goldfish, Carassius auratus and swordtail, Xiphophorus helleri were studied. The total wet weight gain, food conversion ratio and specific growth rate of C. auratus did not vary significantly (p>0.05) among treatments. While in X. helleri, significant differences existed in the total wet weight gain, survival, food conversion ratio and specific growth rate among treatment groups (p<0.05). The counts of antibiotic resistant bacteria in fish gut increased with days of culture in all the treatments and the increase was more in antibiotic fed fishes. A reduction in the development of antibiotic resistance among the bacterial flora of fish gut was noticed in probiotic fed groups of C auratus and X. helleri. The results of the present study revealed that the effects of human probiotic on the growth, survival and disease resistance of ornamental fishes are variable and difficult to reproduce the similar effect on different species.

Effects of different levels of energy and protein sources on the growth performance, feeding, survival rate and the chemical body composition of juvenile Pacific white shrimp (Litopenaeus vannamei)

The present study was carried out in order to establish an economical effective diet for the pacific white shrimp in the southern part conditions of Iran. With the consideration of three dietary energy levels (E1=262, E2=312, E3=362 kcal 100 g-1 diet) and six ratios of fish meal (FM) to soybean meal (SBM) [(P1=100%FM+0%SBM, P2=80%FM+20%SBM, P3=60%FM+40%SBM, P4=40%FM+60%SBM, P5=20%FM+80%SBM, P6=0%FM+100%SBM)], 18 experimental diets (with 36% crude protein) were prepared. Completely randomized design was used to assign 54 polyethylene 300 litre round tanks provided by aeration and flow through water system and was stocked by 19 juvenile as 3 replicates to each treatment. Shrimps average weight was about 0.77 grams at the start. After 56 days culture period, maximum growth and nutritional performances were observed in the P6E1 treatment (containing 100% soybean meal and 262 kcal 100 g-1 diet) and P5E1 treatment (containing 80% soybean meal and 262 kcal 100 g-1 diet). Also the highest survival rate of the shrimps was observed in the P1E1, P1E2, P3E3 and P5E3 treatments. Additionally interactive effect of different protein ratios and energy levels had significant difference on body protein, fat, fiber and ash contents (P<0.05). Results of the present study suggest the possibility replacement of at least 80% of dietary fish meal by soybean meal in the diet of pacific white shrimp in the conditions of southern part of Iran.

The survey on growth and survival rate parameters with slurry and comparison by common method

This project was on “Study of Slurry, as an enrichment compound, on growth and survival parameters of Rutilus firisii kutum Kamensky 1901 larva and compare with routine condition according to hypothesis that use of Slurry, fertile organic compound, to increase the efficiency of survivorship and growth of Rutilus firisii and in other hand adaptation of natural food was performance.” The object of this project is to compare growth of Rutilus firisii and in usual condition and the condition of use Slurry The experiences performed in culture and propagation center Dr. Yousefpour decent (Associan of Dr. Beheshti culture and propagation) in Siahkal village, 32 Km far from southeast, in North of Iran. In this plan, three different treatments and related these nine pools , in 1.7 hec area (in same condition) were determined so that the density of storage was 1.7 million/hec larva. In this research at first treatment m we use slurry as enrichment compound during larval within a period of 13 days, and it used all the days of during larval in second treatment. Then the result of this study compared to control treatment. The results have shown the level of this study compared to control treatment. The results have shown the level of survivorship in pools were nutrition by slurry was 1.7 million times or twice than pools were nutrition with usual concentrate. In addition, growth coefficient such as daily weight growing (DWG) index, daily length growth (DLG), specific growth ratio (SGR) were measured in this case. All of these parameters in slurry treatment were shown noticeable enhancement in first treatment Thereof in the first week there was significant difference (P<0.001) between the average of length and weight in first week , and in the second week there was a significant difference (P<0.05) between them.

Effect of replacement of fish meal with soybean meal plus supplementary enzymes on growth performance, survival rate and apparent digestibility of rainbow trout (Oncorhynchus mykiss)

This study was carried out to measure the effects of a supplementary multi enzyme on growth performance , survival rate and apparent protein digestibility of rainbow trout fed some diets containing different amounts of soy bean meal. Five exprimental diets with replacement of 25, 50, 75 and 100 percent of fish meal protein by soy bean meal protein were made and 0, 500 and 1000 ppm dosages of supplementary multi enzyme had used in each of them. By the means a diet with fish meal as the only source of protein has used as the control. So this study had 13 treatments. The trouts in 89.40±4.01 gr mean weight were stocked in 39 experimental fiberglass tanks in abundance of 30 fish per any tank. These specimens fed experimental diets for 8 weeks and ten of them in each tank fed same diets which added Cr2O3 to them for one more week to measure the apparent protein digestibility in them. The results shown that supplementary multi enzyme (Avizyme) which contains Protease , Amylase and Xylanase , caused increases in growth performance , survival rate and apparent protein digestibility in trouts which fed soybean meal. Also this study shown that using 1000 ppm of Avizyme in diets which containing soybean meal had the best results and the diet which contained 39 % soybean meal with this amount of enzymes, had no significant differences by the control in any of the studied factors.

The study of the ergosan and vibromax effects on growth performances, survival rate and increase of the resistance to some of the environmental stresses in post larvae stage of the Indian white shrimp

In this study, which has been done in Hormoz larve Hatchery at Kohestak in Minab at 1385, the efficiency of Ergosen and Vibromax vaccine and the effect of them on growth factors such as total length, Carapase, dry weight and the number of upper mordents of rostrum and survival of the stages of larvae and post larvae of Indian white shrimp was studied. Thus in order to comparison the effects of Vibromax and Ergosen, each of them separately, in one treatment, and in another simultaneously with one control treatment was used. Vaccination against larvae shrimps was done through Artemia. This study used four treatments with three replicates in a completely randomized design and comparison of means was done through Duncan test. Breeding larvae and post larvae of Indian white shrimp from zoa I stage to PL 15 was done in 20 litter plastic buckets. Present results indicated that the highest amount of growth and survival factors in larvae stage (from zoa to PL1), and also in stages of PL5 and PL15, in the treatment of Ergoson effect + vaccine and it was with a little difference from that treatment of Ergoson effect which was in high significance difference in regard to control treatment at α<0.01 level and treatment of vaccine effect and control treatment at α<0.01 level often have no significant difference. This research used environmental stress tests to study the quality of post larvae under experiment. Studying in this field showed that feeding vaccine to larvae of Indian shrimps which was done through Artemia nauplii enrichment ,and ergosen , in treatment of ergosen vaccine lead to more resistance of post larvaes against salinity stress tests and formalin .This case was observed in every three stages ,so that in stress formalin test 100 parts per million and also 10 and 20 salinity parts in thousands the most survival was observed in treatment of Ergosan effect+vaccine and after that in treatment of Ergoson effect and with a little difference in treatment of vaccine effect. Of course this case, in treatment of Ergoson effect + vaccine due to the synergistic properties vaccine with Ergoson was more than to other treatments, while every three treatments, in most stages had significant difference toward control treatment at α<0.01 level and the control treatment because of not having Ergoson and nauplii artemia with vaccine, having the least survival rate in this stages.