تاثیر شوری‌های مختلف بر برخی فاکتورهای رشد، بقا و بافت روده‌ی بچه‌ماهی اوزون‌برون (acipenser stellatus)

ﻫﺪف از اﯾﻦ ﻣﻄﺎﻟﻌﻪ ﺗﻌﯿﯿﻦ ﺷﻮری ﺑﻬﯿﻨﻪ ﺟﻬﺖ ﭘﺮورش ﺑﭽﻪﻣﺎﻫﯿﺎن اوزونﺑﺮون )acipenser stellatus( در ﻣﺤﯿﻂﻫﺎی ﻣﺤﺼﻮر ﺑﻮد. ﺑﭽﻪﻣﺎﻫﯿﺎن ﺑﺎ ﻣﯿﺎﻧﮕﯿﻦ وزن اﺑﺘﺪاﯾﯽ 1/54 ± 54/11 ﮔﺮم در ﻣﺨﺎزن ﻓﺎﯾﺒﺮﮔﻼس 500 ﻟﯿﺘﺮی )ﻣﯿﺎﻧﮕﯿﻦ دﻣﺎﯾﯽ c° 0/14 ± 22/58( در ﯾﮏ ﮔﺮوه ﺷﺎﻫﺪ )آب ﺷﯿﺮﯾﻦ( و دو ﮔﺮوه ﺗﯿﻤﺎری )6 و 12 ﮔﺮم در ﻟﯿﺘﺮ( ﻫﺮ ﯾﮏ ﺑﺎ 3 ﺗﮑﺮار ﺑﺮای ﻣﺪت 60 روز ﭘﺮورش داده ﺷﺪﻧﺪ. ﻣﺎﻫﯽﻫﺎ دو ﺑﺎر در روز ﺑﺎ ﻏﺬای ﺗﺠﺎری )ﻏﺬای اﮐﺴﺘﺮود ﺧﺎوﯾﺎری ffs1، ﺳﺎﯾﺰ 2، ﺷﺮﮐﺖ ﻓﺮاداﻧﻪ، اﯾﺮان(، ﻣﻮرد ﺗﻐﺬﯾﻪ ﻗﺮار ﮔﺮﻓﺘﻨﺪ. در ﭘﺎﯾﺎن دورهی ﭘﺮورش، ﻧﺮخ رﺷﺪ وﯾﮋه )sgr(، اﻓﺰاﯾﺶ وزن )wg(، ﺷﺎﺧﺺ وﺿﻌﯿﺖ )cf( و ﺷﺎﺧﺺ ﻫﭙﺎﺗﻮﺳﻮﻣﺎﺗﯿﮏ )hsi( در ﻣﺎﻫﯽﻫﺎی ﮔﺮوه 12 ﮔﺮم در ﻟﯿﺘﺮ در ﻣﻘﺎﯾﺴﻪ ﺑﺎ ﮔﺮوه ﺷﺎﻫﺪ ﺑﻪﻃﻮر ﻣﻌﻨﯽداری اﻓﺰاﯾﺶ ﯾﺎﻓﺖ ) p≤0/05 (. از ﺳﻮی دﯾﮕﺮ ﺿﺮﯾﺐ ﺗﺒﺪﯾﻞ ﻏﺬاﯾﯽ )fcr( در ﮔﺮوهﻫﺎی ﺗﯿﻤﺎری ﺑﻪﻃﻮر ﻣﻌﻨﯽداری ﮐﺎﻫﺶ ﯾﺎﻓﺖ )p≤0/05(. ﻧﺮخ ﺑﻘﺎی ﻣﺎﻫﯽﻫﺎ 100% ﺑﻮد. ﻃﻮل ﭘﺮز و ﻓﻀﺎی داﺧﻠﯽ روده در ﮔﺮوه ﺗﯿﻤﺎری ﺑﺎ ﺷﻮری 12 ﮔﺮم در ﻟﯿﺘﺮ ﺑﻪﺗﺮﺗﯿﺐ اﻓﺰاﯾﺶ و ﮐﺎﻫﺶ ﻣﻌﻨﯽ داری ﻧﺸﺎن دادﻧﺪ )0/05 ≤ p(. ﻧﺘﺎﯾﺞ ﺑﻪدﺳﺖ آﻣﺪه ﻧﺸﺎن دادﻧﺪ ﮐﻪ ﺷﻮری ﺑﻬﯿﻨﻪ در اﯾﻦ ﻣﺮﺣﻠﻪ از زﻧﺪﮔﯽ ﻣﺎﻫﯽ اوزونﺑﺮون، ﺷﻮری درﯾﺎیﺧﺰر )12 ﮔﺮم در ﻟﯿﺘﺮ( اﺳﺖ ﮐﻪ ﺷﺮاﯾﻂ را ﺑﺮای ﻣﻌﺮﻓﯽ اﯾﻦ ﮔﻮﻧﻪ ﺑﻪ ﻋﻨﻮان ﮔﻮﻧﻪ ﻣﻨﺎﺳﺐ ﭘﺮورش در ﻣﺤﯿﻂﻫﺎی ﻣﺤﺼﻮر ﻣﻨﺎﺑﻊ آبﻫﺎی ﻃﺒﯿﻌﯽ ﺗﺄﻣﯿﻦ ﻣﯽﻧﻤﺎﯾﺪ. ﺑﺮ ﭘﺎﯾﻪ اﯾﻦ ﻧﺘﺎﯾﺞ ﻣﯽﺗﻮان ﮔﻔﺖ ﮐﻪ ﺳﺎزﮔﺎری ﺑﺎ آب ﺷﻮر 12 ﮔﺮم در ﻟﯿﺘﺮ ﺟﻬﺖ اﻓﺰاﯾﺶ درﺻﺪ ﺑﻘﺎ و ﺑﻬﺒﻮد رﺷﺪ اﯾﻦ ﮔﻮﻧﻪ ﻗﺒﻞ از ﻣﻌﺮﻓﯽ ﺑﻪ ﻣﺤﯿﻂﻫﺎی ﻣﺤﺼﻮر در ﻧﺎﺣﯿﻪ ﺟﻨﻮﺑﯽ درﯾﺎی ﺧﺰر، ﺿﺮوری اﺳﺖ.

the effect of different salinities on some growth factors, survival and intestinal tissue of starry sturgeon juvenile (acipenser stellatus)

the aim of this study was to determine the optimal salinity for rearing the juveniles of starry sturgeon (acipenser stellatus) in enclosed environments. sturgeon with an average initial weight of 54.11 ± 1.54 g were raised in 500-liter fiberglass tanks (average temperature 22.58 ± 0.14 °c)in a control group (freshwater) and two treatment groups (6 and 12 g/lit) in 3 replicates for 60 days. they were fed with commercial feed (sturgeon extruded food ffs1, size 2, faradaneh company, iran) twice a day. at the end of the rearing period, specific growth rate (sgr), weight gain (wg), condition factor (cf) and hepatosomatic index (his) in experimental fish (12 g/lit) were significantly elevated compared to control fish. food conversion ratio (fcr), on the other hand, was significantly reduced in the experimental fish. the survival rate of fish was 100%. intestinal villi length and internal space were significantly elevated and reduced in 12 g/lit salinity, respectively. the results suggest that the optimal salinity at this point of starry sturgeon life is the caspian sea water salinity (12 g/lit) which provides the conditions for introducing this species as a suitable species for rearing in enclosed environments in natural water resources. based on these results, it is suggested that adaptation to salt water of 12 g/lit is necessary to increase the survival rate and improve the growth of this species before introducing it to the enclosed environments in the southern region of the caspian sea.