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1.
J Environ Biol ; 2019 May; 40(3): 328-334
Article | IMSEAR | ID: sea-214558

ABSTRACT

Aim: The present study was undertaken to find out the possibilities of induced breeding of Catla catla, at low water temperature using fibre reinforced (FRP) tanks in a carp hatchery. Methodology: Brood fish of C. catla was maintained in 0.1 ha pond with proper feeding and pond management. Six induced breeding programmes: 3 in April (pre-monsoon) and 3 in June (monsoon) of 2017 were conducted with C. catla using synthetic hormone, Ovasis intra-peritoneally. The relationship between temperature variation and latency period, effective spawning period, fecundity, hatching start time, hatching duration and spawn production with its recovery was observed. Results: The latency period (time gap between injection and first egg release) was very high and ranged between 653.3 and 721.6 min for breeding in the pre-monsoon and ranged between 446.6 and 480 min for monsoon period. In pre-monsoon, the effective spawning period between 86.6 and 116.6 min and in monsoon between 53.3 and 73.3 min; both varied significantly (p˂0.05). In pre-monsoon period, the average water temperature during larval incubation in hatching pool ranged between 21.58 and 22.58ºC, whereas during monsoon period it ranged between 30.1 and 30.4ºC. The spawn production was 0.13 to 0.22; and 0.47 to 0.65 (lakh kg-1 b. wt. of female) in pre-monsoon and monsoon period, respectively, and showed a significant difference (p˂0.05). Interpretation: This report on breeding of C. catla in the temperature range of 18.6-24.7oC indicates the possibility of spawn production of Indian Major Carp in the north east hilly region states of India

2.
J Environ Biol ; 2010 May; 31(3): 301-306
Article in English | IMSEAR | ID: sea-146366

ABSTRACT

Physico-chemical and microbial characteristics of culture water were examined during the induced breeding of Cyprinus carpio in a controlled environmental system. Water temperature, dissolved oxygen, nitrate, phosphate, pH, ammonia nitrogen, total bacterial count, hardness, salinity, carbonate and bicarbonate were estimated before and after spawning and hatching. Average alteration in water pH before and after spawning was 7.91-7.57 and 7.86-7.58 respectively. Total hardness, carbonate and bicarbonate showed insignificant variations. Nitrate, ammonia nitrogen and phosphate contents significantly increased after spawning and hatching p<0.05. The average increase in nitrate was from 2.94 to 8.62 /g l-1 after spawning and 3.10 to 8.49 /g l-1 after hatching. Ammonia nitrogen contents were sharply increased from an average of 0.011 to 1.87 mg l-1 after spawning and 0.013 to 0.56 mg l-1 after hatching. The average phosphates increased from 2.59 to 4.15 /g l-1 after spawning and 2.61 to 4.03 /g l-1after hatching. Dissolved oxygen was sharply depleted even after a continuous aeration. Temperature played a vital role during breeding. No successful breeding was observed at a temperature of 17oC or below and 31oC or above. There is a significant association between temperature, spawning and hatching (p<0.05). By optimizing temperature, the breeding success of this carp was achieved with a statistical significance of p<0.05. Total bacterial count was significantly increased after spawning and hatching. It was related to the amount of discharge and may cause mass mortality of fish embryo and spawn in a closed hatchery system.

3.
Microbiology ; (12)1992.
Article in Chinese | WPRIM | ID: wpr-685226

ABSTRACT

The protoplasts of original Aspergillus niger strain Uco-3 were treated with the cooperation of UV and ?-ray to obtain the high-yielding strain producing the thermostable ?-galactosidase. Under the optimum conditions of formation and regeneration protoplasts were prepared. According to the interaction of positive mutation rate and radiation dose,the optimum condition was determined. The optimum dose of UV was 4 minutes and the optimum dose of ?-ray was 500 Gy. After mutagenetic treatment of protoplasts and selection from a lot of mutants,a mutant DL116 producing the thermostable ?-galactosidase was obtained. The ?-galactosidase activity of DL116 was increased from 16.27 U/mL to 44.37 U/mL,which was higher than that of strain Uco-3.

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