Influence Of Four Specises Of Marine Algaes On The Growth, Shell Pigment And Polysaceharide Lyase Of Haliotis Discus Hannai Ino

The research took the 6th generation juvenile abalones of the Haliotis discus hannai Ino 97 breeding population as the object of study, feeding them with Saccharina japonica, Ulva lactuca, Porphyra haitanensis and Gracilaria lemaneiformis respectively, aiming to understand the effects of four kinds of algaes on the growth, shell color, pigment and polysaceharide lyase of different groups. The main results are showed as follow:1 Effect of four kinds of algaes on the growth and the survival rate of juvenile abalonesAmong four groups, the average shell length, shell width and wet weight of juvenile abalones were greatly influenced by the algaes. Ulva lactuca treatment group had the highest growth rate of shell length, shell width, wet weight and specific growth rate. however, the growth indexes of Gracilaria lemaneiformis were the lowest. The growth parameters of Saccharina japonica feeding group were in the middle. There were significant differences on growth characters among four different groups.In addition, the daily growth rate of shell length, shell width and wet weight of Ulva lactuca treatment group were higher than those of the other 3 kinds of treatment groups. However, these indicators of Gracilaria lemaneiformis group were less than other groups.The survival numbers of juvenile abalones which were fed with Ulva lactuca, Saccharina japonica, Gracilaria lemaneiformis and Porphyra haitanensis were 150、 147、146 and 138. The average survival rate of the four treatment groups was 100%、 98.00%、97.33% and 92.00%, which indicated that the experimental system and the juvenile abalones were both in good condition.2 Effect of four kinds of algaes on the shell colour and pigments of juvenile abalonesThe observations on shell color showed that the shell edges of the Haliotis discus hannai Ino which feed with Saccharina japonica and Ulva lactuca were green, while that in Porphyra haitanensis and Gracilaria lemaneiformis were reddish-brown. Compared with other pigments, the shells of Saccharina japonica group were rich in fucoxanthin, while the content of chlorophyll in Ulva lactuca group was significantly higher than that of other pigments. The phaeophyta was high in fucoxanthin and chlorophyta was rich in chlorophyll a, which meant that there was some correlation between the pigment in the algaes and in the shell.3 Effect of four kinds of algaes on the polysaceharide lyase of juvenile abalones A. Effect of four kinds of algaes on the gene expression of polysaceharide lyase of juvenile abalonesThe gene expression of polysaceharide lyases such as alginase, cellulase as well as a-amylase is studied with Q-PCR on transcriptional level, the results of which suggest that there are significant differences in the gene expression abundance of the 3 kinds of polysaceharide lyases in the digestive glands of the juvenile abalones which are fed with different algaes. The relative expression quantity of alginase in the digestive glands of Saccharina japonica group is notably higher than the other three groups, while that of a-amylase in Porphyra haitanensis and Gracilaria lemaneiformis group is markedly higher than other groups, and that of a-amylase in Porphyra haitanensis group is approximately 7 times of that in Saccharina japonica group.B. Effect of four kinds of algaes on the polysaceharide lyase activity of juvenile abalonesThe alginase activity of juvenile abalones which were fed with Saccharina japonica was the highest, which was about 7.26 times of that in Gracilaria lemaneiformis group, and the alginase activity of Gracilaria lemaneiformis feeding group was the lowest; the a-amylase activity of juvenile abalones which were fed with Vlva lactuca and Gracilaria lemaneiformis was the highest, which was the lowest in Porphyra haitanensis feeding group; the cellulase activity of juvenile abalones which were fed with Saccharina japonica was the highest, which was about 4.75 times of that in Gracilaria lemaneiformis group, and the cellulase activity of Gracilaria lemaneiformis feeding group was the lowest.C. Effect of food exchange on polysaceharide lyaseAlginase, cellulase and a-amylase are inducible enzymes, the gene expression of which are regulated by substrates. The changing of food can quickly induce the up-regulation or down-regulation in the expression of polysaceharide lyase genes. The molecular regulation mechanism of the digestion and utilization of carbohydrate nutrients remains to be further investigated.