تاثیر تراکم مختلف‌ بچه ماهیان کوی (cyprinus carpio var. koi) در استخرهای سیمانی، خاکی و مخازن فایبرگلاس بر برخی پارامترهای رشد و رنگ پوست

ﻣﻄﺎﻟﻌﻪ ﺣﺎﺿﺮ ﺑﺎﻫﺪف ﻣﻘﺎﯾﺴﻪ ﺗﺄﺛﯿﺮ ﺗﺮاﮐﻢﻫﺎی 20، 25و 30ﻋﺪد ﻣﺎﻫﯽ در ﻫﺮ ﻣﺘﺮﻣﮑﻌﺐ ﺑﺮ ﭘﺎراﻣﺘﺮﻫﺎی رﺷﺪ و رﻧﮓ ﭘﻮﺳﺖ ﺑﭽﻪ ﻣﺎﻫﯿﺎن ﮐﻮی cyprinus carpio var. koi وزن اوﻟﯿﻪ 1/9±0/8ﮔﺮم در اﺳﺘﺨﺮﻫﺎی ﺳﯿﻤﺎﻧﯽ، ﺧﺎﮐﯽ و ﻣﺨﺎزن ﻓﺎﯾﺒﺮﮔﻼس ﺑﺎ ﻇﺮﻓﯿﺖ 1000 ﻟﯿﺘﺮ در 9ﺗﯿﻤﺎر و ﺳﻪ ﺗﮑﺮار ﺑﻪ ﻣﺪت 45روز ﺑﺮرﺳﯽ ﺷﺪ. در ﭘﺎﯾﺎن دوره آزﻣﺎﯾﺶ ﺑﯿﺸﺘﺮﯾﻦ وزن ﻧﻬﺎﯾﯽ 12/38±1/92ﮔﺮم ، ﻃﻮل ﻧﻬﺎﯾﯽ 1±05/6/ 10ﺳﺎﻧﺘﯽ ﻣﺘﺮ ، اﻓﺰاﯾﺶ وزن 8/4±1/3ﮔﺮم ، اﻓﺰاﯾﺶ ﻃﻮل 9/51±1/96ﺳﺎﻧﺘﯽ ﻣﺘﺮ ، درﺻﺪ اﻓﺰاﯾﺶ وزن 551/57±2/48 درﺻﺪ ، ﻧﺮخ رﺷﺪ وﯾﮋه 3 /73±0/05درﺻﺪ در روز ، درﺻﺪ ﺑﻘﺎء 100درﺻﺪ و ﮐﻤﺘﺮﯾﻦ ﺿﺮﯾﺐ ﺗﺒﺪﯾﻞ ﻏﺬاﯾﯽ 0/74±0/08 در اﺳﺘﺨﺮﻫﺎی ﺳﯿﻤﺎﻧﯽ ﺑﺎ ﮐﻤﺘﺮﯾﻦ ﺗﻌﺪاد ﺗﺮاﮐﻢ ﻣﺸﺎﻫﺪه ﺷﺪ 0/05

effect of different stocking density on some growth performance and skin color of koi carp fry (cyprinus carpio var. koi linnaeus, 1758) reared in concrete, earthen and fiberglass ponds

the aim of this study was to elevate the effect of stocking density of 20, 25 and 30 fish/m3 on some growth parameters and skin color of koi fry cyprinus carpio with the mean weight of 1.9 ±0.8 g ±se in the concrete ponds, earthen ponds, and fiberglass tanks with the total capacity of 1000 l for 45 days. the highest final weight 12.38±1.9 g , final length 10.05±1.06 cm , body weight increase 8.4±1.3g , body length increase 9.51±1.96 cm , percent body weight increase 551.57±2.48% , specific growth rate 2.73±0.05%/day , survival rate 100% and the lowest feed conversion ratio 0.74±0.08 were observed in cultured koi fry in concrete ponds at the stocking density of 20 fish/m3 p<0/05. however, no significant differences between koi fry cultured at stocking density of 20 and 25 fish/m3 in concrete ponds was observed p>0/05 the results of skin color revealed that the highest level of lightness 56.93±0.03 and the redness color 3.64±0.03 spectrums in koi fry it was seen in in the concrete tanks at the lowest stocking density and the highest color purity 14.75±1.2 , yellow color spectrum 14.31 ± 0.03 and chroma 20.66±2.09 were observed in concrete tanks at the stocking density of 25 fish/m3. in conclusion, the results of this study indicated that rearing of koi fry in concrete ponds with stocking density of 20-25 fish/ m3 have a positive effect on growth performance, feed efficiency and skin colors of the fish compared to other rearing containers at he similar or higher stock density.