اثر استفاده از ناپليوس آرتمياي غني شده با اسيدهاي چرب ﴿HUFA﴾ بر بازماندگي ، رشد و مقاومت به تنش هاي محيطي در نوزاد فرشته ماهي ﴿Peterophylum scalare﴾

چكيده انگليسي :

Effects of Enrichment of Artemia Nauplii With HUFA on Growth Survival and Resistance to Environmental Stress in Larvae of Angel Fish Peterophylum scalare Mehran Yaghoubi Yaghoubi mehran@gmail com Date of Submission 14 02 2011 Department of Natural Resources Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor Dr Eisa Ebrahimi e ebrahimi@cc iut ac ir Abstract Success in hatchery production system largely depends on the availability of suitable live feed organisms for feeding the sensitive fry and fingerling stages of fish Live feed is an essential food source for the fry of cultured species especially those without a fully developed digestive system Two major concerns of aquaculturists are i providing organisms appropriate to the size of the feed to the first feeding stage and ii supplying adequate number of feed organisms to ensure higher survival and faster growth In the freshwater ornamental fish culture Artemia nauplii are used as the live feed But Artemia is poor in essential fatty acids especially in n 3 HUFA and cannot fulfill the dietary requirements of the marine fish and shrimp larvae alone Therefore enrichment techniques has been introduced for enrichment of Artemia nauplii before they are used for feeding the larvae In this research the use of Artemia nauplii enriched with highly unsaturated fatty acids HUFA were investigated on survival growth and resistance of angel fish Peterophylum scalare larvae The larvae with average weight of 0 86 mg were reared for 20 days using three feeding regimes including newly hatched Artemia nauplii nauplii enriched with HUFA and powdered commercial feed Biomar France larvae were solely fed on commercial food for another 20 days Larvae were feed four times per day in 8 12 16 and 20 The results showed that survival of the larvae on day 20 was significantly higher in the group fed on nauplii enriched with HUFA 90 66 compared to those fed on newly hatched nauplii 83 66 and fed on commercial feed 0 P 0 05 The larvae fed on commercial feed suffered 100 mortality during first three days of the culture Significantly higher growth parameters including final weight specific growth rate total length percent weight gain and height were detected in larvae fed on enriched nauplii compared to the larvae received unenriched nauplii On day 20 and 41 the larvae were exposed to stressful conditions 22 and 34 C temperature pH 5 5 6 5 8 5 and 9 5 the larvae fed with HUFA enriched Artemia showed better resistance against pH stress than the other groups P 0 05 larvae fed on enriched nauplii during first 20 days had significantly higher growth parameters including final weight specific growth rate percent weight gain and height at the end of second feeding period day 40 P 0 05 at the end of 20th days of second experiment day 40 there was not seen any significant differences at survival rate and total lenght among treatments No significant differences were detected in the survival percent between the two period when exposed to high temperature While the larvae fed on enriched nauplii demonstrated higher resistance to pH changes and not seen any significantly differences at survival rate when exposed to stressful pH condition P 0 05 In conclusion the results of this study showed that the larvae fed on nauplii enriched with HUFA show higher survival growth and resistance to environmental stresses compared to unenriched nauplii and commercial feed Key words Angel fish Peterophylum scalare Artemia nauplii HUFA temperature stress pH stress

يعقوبي، مهران

اثر استفاده از ناپليوس آرتمياي غني شده با اسيدهاي چرب ﴿HUFA﴾ بر بازماندگي ، رشد و مقاومت به تنش هاي محيطي در نوزاد فرشته ماهي ﴿Peterophylum scalare﴾

بازماندگي , استرس دمايي , استرس PH