Effects of dietary vitamin E on the growth and breeding performance of Ompok pabda

A 90 day feeding trail was conducted to investigate the effect of vitamin E on the growth and breeding performance of Ompok pabda. A total of 84 healthy female brood fish (41.10±0.44g) were divided into 4 treatments i.e. treatment T1 T2, T3 and T4 having three replications each. The fish were fed twice a day with a standard feed (40% protein) having 4 doses of vitamin E viz. 0 (served as control), 50, 100 and 150mg vitamin E/kg feed. At the end of the feeding trial, the brood fish were induced to breed with PG extract to observe the effect of vitamin Eon feed. After rearing for 90 days with the experimental feeds, it was found that weight gain and specific growth rate of brood fish fed with 100mg vitamin E/kg feed (treatment T3) was the highest (14.78±0.38g and 2.99±0.11) while 150mg vitamin E/kg feed (treatment T4) fed fish gave the poorest result (2.97±0.89g and 1.21±0.32). There was no significant difference in terms of length gain of brood fish among the different treatments. The brood fish were induced to breed with equal dose of PG extract (18 and 12mg PG/kg body weight for female and male respectively) to observe the dietary effect of vitamin E on breeding performance. The highest ovulation, fertilization and hatching rate of eggs were found to be 81.48±6.41%, 84.04±3.53% and 68.59±5.03% respectively in the brood fish of treatment T1 while the poorest (33.33±00%, 52.35±5.02% and 45.70±7.24% respectively) were found in the brood fish under treatment T4. The results suggest that inclusion of 100mg vitamin E/kg feed is best for enhancing the breeding performance of O. pabda brood fish indicating that vitamin E content has a positive impact on reproduction of fish. The present results also imply that inclusion of higher level of vitamin E exerts an antagonistic effect in terms of growth and breeding performance of this species

Culture suitability of two exotic catfishes (Clarias gariepinus and Pangasius hypopthalamus) with an indigenous catfish (Heteropneustes fossilis)

Culture experiment of African catfish ( Clarias gariepinus) and Thai pangas (Pangasius hypopthalamus) with indigenous stinging catfish (Heteropneustes fossilis) was conducted in the laboratory. The study was conducted for two experiments, where C. gariepinus and P. hypopthalamus were used separately with H fossilis for a duration of 2l days with three feeding treatments, viz. Tubificid worms (T1), SABINCO feed (T2), and no supplemental feed (T3). In experiment 1, the initial length and weight of 4.4cm and 0.60g of C. gariepinus became 6.74cm and 2.33g when fed Tubificid worms, 7.07cm and 2.84g when fed SABINCO feed in the treatment without supplemental feed the final length and weight were 3.67cm and 0.3lg at the end of 21 days of trial. The final length and weight of H fossilis reached 4.55cm and 0.53g from the initial 3.3cm and 0.25g under the treatment fed Tubificid worms while those fed SABINCO feed showed a length and weight of 4.37cm and 0.45g respectively. However, both the initial length and weight were reduced to 2.85cm and 0.12g respectively in the treatment without supplemental feed. In experiment 2, the initial length and weight of 4.37cm and 0.57g of P. hypopthalamus became 5.57cm and 0.57g when fed Tubificid worms, 4.85cm and 0.82g when fed SABINCO feed in the treatment without supplemental feed the final length and weight reduced to 3.95cm and 0.34g at the end of 21 days of trial. The final length and weight of H fossilis reached 5.19cm and 0.82g from the initial 3.25cm and 0.20g under treatment fed Tubificid worms while those fed SABINCO feed showed the final length and weight of 4.93cm and 0.70g respectively. And both the initial length and weight were reduced to 3.07cm and 0.04g respectively in the treatment without supplemental feed. No predatory effect of C. gariepinus and P. hypopthalamus on H fossilis was observed in the experiments

Effect of diazinon 60 EC on Anabas testudineus, Channa punctatus and Barbodes gonionotus

Anabas testudineus, Channa punctatus and Barbodes gonionotus were exposed to 5.62, 6.25, 6.87, 7.50, 8.12 and 8.75 ppm; 1.13, 2.26, 3.39, 4.52, 5.65 and 6.78 ppm; and 2.00, 2.50, 3.00, 3.50, 4.00 and 4.50 ppm of Diazinon 60 EC, respectively. The median lethal concentration (LC50) values of Diazinon 60 EC on A. testudineus, C. punctatus and B. gonionotus were 6.55, 3.09 and 2.72 ppm for 96 hrs of exposure. The fish species showed several abnormal behaviors which included restlessness, arena movements, loss of equilibrium, increased opercular activities, strong spasm, paralysis and sudden quick movements during the exposure. For histopathological studies, A. testudineus, C. punctatus and B. gonionotus were exposed for 7 days to sublethal concentrations of 1.13 and 3.75 ppm; 1.13 and 2.26 ppm; and 1.13 and 2.26 ppm of Diazinon 60 EC, respectively. Hypertrophy, necrosis and pyknosis of hepatocytes, pyknosis and degenerative changes such as necrosis of tubular and haematopoietic cells of kidney were the major histopathological effects

Rearing of catfish (Clarias batrachus Lin.) larvae with live and prepared feeds

Provision or live feed (Tubificid worms) attributed significantly better weight gain in the five days old Clarias batrachus larvae when reared for another 28 days compared to those fed mixed feed (live and artificial) and artificial feed only. Larvae fed mixed feed showed significantly better weight gain compared to those fed only artificial feed and the survival rate was similar to those fed only live feed. Both the weight gain and survival rate were the lowest for the larvae reared only on artificial feed

Species interaction between carp species in polyculture system

A three months experiment was conducted to study the species interactions of two carp species in polyculture system under supplemental feeding. Four species of fishes such as silver carp (Hypophthalmichthys molitrix), mrigal (Cirrhina cirrhosus), catla (Catla catla) and common carp (Cyprinus carpio) were cultured in four different combinations each containing two species. The combination of silver carp and mrigal in treatment 1, and silver carp and common carp in treatment 2 resulted better growth and production than other two treatments of different combinations of catla and common carp, and catla and mrigal

Acute toxicity of chlorpyrifos, cadusafos and diazinon to three Indian major carps (Catla catla, Labeo rohita and Cirrhinus mrigala) fingerlings

Fingerlings of three Indian major carps, viz. Catla catla (Hamilton-Buchanon), Labeo rohita (Hamilton-Buchanon) and Cirrhinus mrigala (Hamilton-Buchanon), were exposed to different concentrations of chlorpyrifos (lorsban 10 G), cadusafos (rugby 10 G) and diazinon (basudin 10 G) for a period of 96h with a view to determine the median lethal concentrations (LC sub50) values for each of chemicals. Of the tested concentrations, chlorpyrifos at a dose of 6.65 ppm, cadusafos at 2.0 ppm and diazinon at a dose of 8.40 ppm or above induced 100% mortalities within 96h of exposure. The 96h LC sub50 values of chlorpyrefos, cadusafos and diazinon were 1.66, 0.72 and 2.10 ppm for C. catla, 2.35, 0.72 and 2.97 for L. rohita and 2.35, 0.72 and 2.10 ppm for C. mrigala, respectively. Pesticide induced behavioral abnormalities observed in the present study included erratic movements, rapid operculum activities, jumping of fish out of the test media, violent spasm and convulsion

Growth and survival of Clarias batrachus (Lin.) larvae fed on formulated diets

An experiment was conducted for a period of 28 days using 7-day old C. batrachus larvae of initial total length (±S.D.) of 7.4 ± 0.49 mm and weight (±S.D.) of 2.8 ± 0.75 mg. Five test diets viz. diets I, II, III, IV and V were prepared. Diet I was formulated using 30% fish meal (FM), 20% soybean meal (SM) and 20% Baker's yeast (BY), diet III using 15% FM, 20% SM, 15% cotton seed meal and 30% BY and diet IV using 20% FM, 30% BY and 30% powdered milk. The remaining two diets (diets II and V) were prepared using minced clam meat (96%) and BY (90%) respectively as the sole source of protein. Three replications were used for each treatment. The larvae fed on diet II exhibited significantly (P<0.05) better length gain and specific growth rate (SGR) than those of the larvae fed on diet III and there was no significant difference among the length gain and SGR of the larvae fed on diet I,II,IV and V. The larvae fed on diet II also showed significantly better weight gain and survival than those of the larvae fed on other diets. There was no significant difference between the condition factor of the larvae fed on diet II and IV. However, the larvae fed on diet II showed better condition factor than those of the larvae fed on other diets

Effects of different dietary levels of vitamin E on the breeding performance of Heteropneustes fossilis (Bloch)

Experiments on the study of different dietary levels of vitamin E on the growth and breeding performance of Heteropneustes fossilis brood fish were carried out in two phases. The first phase consisted of studying its ovarian development and the second phase on breeding performance. Sixty female fishes were stocked in twelve experimental chambers of a raceway. The effects of four dietary vitamin E levels viz. 0 (served as control), 50, 100 and 200 mg/kg feed, on the somatic growth, ovarian development of brood fish and on their breeding performance were studied. Each treatment had three replications. It was observed that body growth in terms of length and weight was best with 0 mg vitamin E/kg feed and 200 mg vitamin E/kg of feed gave poorest result. The gonado-somatic index and fecundity, however, was highest in the fish fed with 100 mg vitamin E/kg of feed. In case of breeding performance such as ovulation rate, fertilization rate, hatching rate and survival rate, the best result was obtained with 200 mg vitamin E/kg of feed. The overall result of this experiment indicates that 200 mg vitamin E/kg of feed is the best vitamin E dose for H fossilis brood and vitamin E content has a positive impact on ovarian development

Minimization of cannibalism of African catfish (Clarias gariepinus Burchell) larvae in indoor culture system

For minimizing cannibalism of African catfish (Clarias gariepinus) larvae two trials for a period of 14 and 15 days respectively in four aquaria of size 120x49x32 cm³ were conducted. Seven days old African catfish larvae with an initial total length and weight of 7.84 (±0.40) mm and 4.40 (±1.18) mg respectively in the first trial and similarly 7.52(±0.61) mm and 3.98 (±0.56) mg in the second trial at the rate of same stocking densities of 2500 larvae in each aquarium were stocked in both trials. Cannibalistic larvae were separated by using grader frame from each treatment at 7 days and 5 days interval during first and second trial respectively. Two mesh sizes i.e., 5 mm and 7 mm were used in the grader frame in both trials. Survival rate was significantly higher in T1 than that of T2 in each trial. Grading of larvae with 5 days interval resulted higher survival rate than that of 7 days interval

A comparative study on the embryonic development of gynogen, triploid, haploid and normal diploid embryos of stinging catfish, Heteropneustes fossilis

UV irradiation and cold shock were applied on the eggs of stinging catfish, Heteropneustes fossilis, to produce haploid,. gynogen and triploid embryos. A comparative account of the various features· of embryonic development in chromosomally manipulated groups viz. haploid, gynogen and triploid and non-manipulated normal diploid group of H fossilis has been discussed. A slow development and delayed hatching were observed in gynogen and triploid embryos compared to those in normal diploid (control) groups. Mass mortality was observed in all chromosomally manipulated groups particularly during the gastrulation stage. The hatchlings of the gynogen, triploid and normal diploid were similar in overall appearance