| Studying the effects of coral food preferences and environmental factors on coral feeding is extremely important for coral nursery and coral reef restoration.First,this study compared the effects of three different particle sizes of plankton on the growth performance of Turbinaria peltata,and screened out the best artificial breeding bait for it.Secondly,it confirmed the effects of Turbinaria peltata on rotifers.The effects of the highest predation rate,light,temperature,and p H on the predation behavior of Turbinaria peltata.Finally,the effects of the concentration and proportion of inorganic salts on the feeding behavior of corals under high nutrient conditions and the enhancement of bicarbonate on coral calcification were explored.This paper aims to study the best artificial breeding conditions of Turbinaria peltata,and realize the optimization of Turbinaria peltata breeding conditions.The results are as follows:1.In order to screen the best live feeds for Turbinaria peltata,the effects of three commonly used live feeds(Artemia,rotifers,and chlorella)on the growth rate of coral protein,fat,bone growth rate and fatty acid composition were compared.Twenty coral pieces were selected and randomly divided into 4 groups(3 treatment groups and 1 control group),and each group contained 5 coral pieces.Feed the same quality of Artemia,Rotifera and Chlorella for 45 day.The bone weight of corals was measured before and after the experiment to calculate the growth rate of bones.After the experiment,all corals were used for the detection of related indicators.The experimental results showed that:Among the three diets selected in the experiment,corals fed by rotifers showed the highest bone growth rate(4.67%),protein(180±9.64mg/g wt),and fat content(70.44±9.36 mg/g).The indicators are higher than those of other experimental groups,and it means rotifers are more suitable bait carriers for Turbinaria peltata.(2)Fatty acid results showed that the ratio of C24:1 and C22:6fatty acids in corals fed by rotifers was significantly lower than that of other treatment groups,indicating that the use of rotifers as coral food still needs to further solve the problem of the lack of long-chain unsaturated fatty acids.(2)The feeding rate of corals increases with the increase of temperature,but the number of coral symbiotic zooxanthellae decreases drastically under the condition of 32℃.With the increase of stress time,the feeding rhythm of corals under the condition of 32℃disappears.,The intensity of food intake shows a decreasing trend.2.In order to explore the effects of different culture conditions on the feeding rate of corals,we monitored the effects of different environments(feed density,light conditions,p H conditions)on the feeding rate of corals,and combined the changes in coral photosynthetic rate to analyze the changes in coral feeding rate under different environmental factors s reason.The results are as follows:(1)The feeding rate of Turbinaria peltata under different food densities and light conditions.The results show that Turbinaria peltata have a maximum feeding rate of 194.6ind/L/polyp for rotifers,and corals have a high feeding rate under light conditions.Under dark conditions,the half-saturation constants under light and non-light conditions are6.46×10~3/L and 6.93×10~3/L.(3)The feeding rate of corals decreased with the decrease of p H.At p H 7.8,the feeding rate decreased by 20.00%,and at p H 7.6,the feeding rate decreased by 34.41%.(4)The photosynthetic rate of corals increases with the increase of temperature,and decreases with the decrease of p H.Coral feeding rate also shows the same law,indicating that the autotrophic ability of corals is closely related to the predation behavior of corals.3.Increasing the concentration of inorganic salts can significantly increase the photosynthetic rate of Symbiotic micro-algae,and slightly increase the number of Symbiotic microalgae,which will increase the coral’s feeding rate and decrease the bone growth rate.When the ratio of nitrogen to phosphorus is unbalanced(100:1),the input of hetero-trophic nutrients will further reduce the photosynthetic rate of Symbiotic micro-algae and the growth rate of coral bones.When the ratio of nitrogen to phosphorus is balanced(20:1),the input of hetero-trophic nutrients can increase the photosynthetic rate of Symbiotic micro-algae and the growth rate of coral bones.Bicarbonate can promote the growth of coral bones,and to a certain extent can compensate for the effect of high inorganic salt conditions on coral calcification. |
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