Succession and seasonal variation in epilithic biofilms on artificial reefs in culture waters of the sea cucumber Apostichopus japonicus

Periphytic biofilms in aquaculture waters are thought to improve water quality, provide an additional food source, and improve the survival and growth of some reared animals. In the AsiaPacific region, particularly in China, artificial reefs are commonly used in the commercial farming of sea cucumbers. However, few studies have examined the epilithic biofilms on the artificial reefs. To gain a better understanding of the succession of epilithic biofilms and their ecological processes in sea cucumber culture waters, two experiments were conducted in culture waters of the sea cucumber Apostichopus japonicus in Rongcheng, China, using artificial test panels. On the test panels of succession experiment, more than 67 species were identified in the biofilms. On the test panels of seasonal variation experiment, more than 46 species were recorded in the biofilms. In both experiments, communities of epilithic biofilms were dominated by diatoms, green algae and the annelid Spirorbis sp. In the initial colonization, the dominant diatoms were Cocconeis sp., Amphora spp. and Nitzschia closterium in June, which were succeeded by species of Navicula, Cocconeis and Nitzschia(July to September), and then by Licmophora abbreviata, Nitzschia closterium and Synedra spp. in the following months. A diatom bloom in the autumn and filamentous green algae burst in the summer were also observed. Ecological indices well annotated the succession and seasonal changes in epilithic communities. Multidimensional scaling(MDS) analysis found significant differences in diatom community composition among months and seasons. Fast growth of biofilms was observed in the summer and autumn, whereas the biomass of summer biofilms was largely made up of filamentous green algae. Present results show that the components of epilithic biofilms are mostly optimal foods of A. japonicus, suggesting that biofilms on artificial reefs may contribute important nutritional sources for sea cucumbers during their growth seasons. Future works should include quantitative determination of the contribution of epilithic biofilms to the diet of A. japonicus, potential roles of epilithic biofilms in regulating the water quality of sea cucumber ponds, and the regulation of epilithic biofilms in sea cucumber culture ponds.

Optimization of Cell Line Building for Taxus chinensis var. mairei

[Objective] The paper aims to optimize the abduction and domestication conditions of Taxus chinensis var.Mairei callus.[Method] We compared the efficiencies of callus between different explants and investigated the multiplication conditions of callus and suspended cell culture conditions with the buds,young stems and young leaves from T.chinensis var as the explants.[Results] The effect was the best with the bud as the explants; the best way for sterilizing the explants of T.chinensis var mairei was：streptomycin detergent for 2 h ＋ suds for 3 h ＋ 75% alcohol disinfection for 30 s ＋ 10% sodium hypochlorite solution for 25 min ＋ 1‰ mercury chloride for 10 min; the optimum formula of callus subculture was：B5 ＋ 4.0 mg/L NAA ＋ 0.5 mg/L 2,4-D ＋ 0.2 mg/L GA ＋ 0.5 mg/L 6-BA ＋ 2 g/L AC.[Conclusion] This research built the high efficient regeneration system of T.chinensis var.

2018 China(Shenyang)-Hungary culture exchange week a success

From May 8 to 12,the Shenyang People’s Association for Friendship with Foreign Countries held the 2018 China(Shenyang)Hungary Culture Exchange Week in the northeastern Chinese city.The event was organized under the framework of Belt and Road Initiative.With the popularization of the Belt and Road concept,exchanges and