The effects of temperature and algal diets on the size of rotifers procured under laboratory condition (Brachionus plicatilis Müller, 1786)
Subject Areas : New Technologies in Aquaculture Development
Keywords: Size, temperature, Keywords: Brachionus plicatilis, Chlorella sp, Nannochloropsis sp,
Abstract :
Abstract The marine rotifer Brachionus plicatilis is extensively used as a major live food in fish larvae culture all over the world. In the present study an attempt was made to find out the effect of temperature and feeding conditions on the size of rotifer (Brachionus plicatilis), that was surveyed in Aquaculture Department of Persian Gulf and Oman Sea Ecological Research Institute (PGOSERI)(located in Hormozgan Province) on December 2010. The rotifer was cultured at tree temperature ranges (25, 30 and 35ºC) and fed with two species of microalgae including, Nannochloropsis oculata, Chlorella spp. and mixed of Chlorella spp. & Nannochloropsis oculata. The rotifers were introduced at stocking density of 6 ind/ml for each treatment. In this experiment, the pH was between 7.7 until 9.9; salinity 25 ppt, the density of rotifers in mild aeration was provided and the treatments were exposed to 1500 lux light intensity. The experiment carried out for 7 days. Results revealed that increasing of temperature cause decreasing in the size of length and width of rotifer. The highest size of rotifer was observed at 25 ºC and the lowest size at 35 ºC. There was a significant difference between the size of the length and width of rotifer cultured in 35 Cº and the other levels of temperatures (p<0.05). Also, the combined effect of temperature and algal diets on rotifer size were significant (p<0.05). In all of the experiments, the best result was observed conducted at 35 Cº temperature using mixed of Chlorella sp. & Nannochloropsis sp. as the main food. (length 118.26 & width 94.75 µm)
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