Biological role of northern pike, Esox lucius (Linneaus 1758) in control of aquatic pests in carps culture ponds
The effects of northern pike, Esox lucius , in controlling coarse fish and other pest organisms and enhancing harvest size in carp ponds was investigated. We used two treatments and one control each wit h three replicates. The pike density was 200 and 500 fish individuals per hectar e for the first and second treatments, respectively and the control pond had no pike. The carp density in ponds was 3500 individuals per hectare and stocking ra tes were 55% silver carp, 20% common carp, 10% bighead carp and 15% grass carp. Survival rate of the northern pike in treatments 1 and 2 was 43.8 and 40%, respe ctively. The results showed that the mean ( plus or minus SD) biomass of unwanted fishes (13 species) in the control treatment was 358.8 plus or minus 55.4kg/h and in the first and secon d treatments were 74.2 plus or minus 6.3 and 92.2 plus or minus 10.9kg/h, respectively in the end of the trial period. So unwanted fishes biomass reduced by 79.3% and 74.3% in the two treatments, respectively. Stomach investigation showed that the pike fed mostly on frog juveniles and some pest fishes like Hemiculter leucisculus, Ps eudorasbora parva, Carassius auratus, and few Macrobrachium and aquat ic insects. Also, the average biomass of unwanted fishes like Carassius aurat us, Hemiculter leucisculus, Alburnus alburnus and Pseudoras bora parva of the first and second treatments in comparison to control showe d a reduction of 94, 88.9, 62.4 and 56.82 percent, respectively. A significant d ifference was found in the final mean weight of common carp between treatments a nd control ponds (P<0.05), as the weight of common carp in treatments ponds was 220% more than the control pond. Also, Esox lucius with controlling coars e fish increased cultured fish (such as common carp, grass carp, silver carp and bighead carp) production by about 17.9%.
| Main Authors: | , , |
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| Format: | Journal Contribution biblioteca |
| Language: | Persian |
| Published: |
2010
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| Subjects: | Stomach content, Pond culture, Stocks, Polyculture, Fish culture, Esox lucius, Brackish, Weight, Density, Biomass, Freshwater, |
| Online Access: | http://hdl.handle.net/1834/11681 |
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