Bivalve is the main species of mariculture in China. In 2015, bivalve production was about 12.4 million tonnes, accounting for more than 66% of China’s total mariculture production. The first record of shellfish culture in China, about oyster culture, can be tracked back to 2000 years ago. The large-scale aquaculture started in the 1950s with the breakthrough in seed breeding techniques for Tegillarca granosa and Ruditapes philippinarum. Subsequently, with the promotion of seed breeding and artificial seed collection for mussels, scallops and oysters, the bivalve aquaculture industry has rapidly developed. In the twenty-first century, the scale of bivalve farming is constantly expanding, with increasing culture species and yield. The length of the coastline of China is about 18,000 km comprising 11 coastal provinces (Liaoning, Hebei, Tianjin, Shandong, Jiangsu, Shanghai, Zhejiang, Fujian, Guangdong, Guangxi and Hainan provinces), all suitable for bivalve culture. Due to the significant difference in climate, the distribution of bivalve species is obviously regional. The major culture methods in China are longline culture (major species oysters, scallops, mussels, etc.) and bottom culture (clams). In this paper, we will describe the process of the longline cultured bivalve (Pacific oyster Crassostrea gigas and thick shell mussel Mytilus coruscus), and the bottom cultured ones (Manila clam Ruditapes philippinarum and cockle clam Tegillarca granosa). 贝类是中国海水养殖的主要种类,2015年贝类养殖产量约为1360万吨,占中国海水养殖总产量的72.4%,其中双壳贝类产量约为1240万吨,占贝类总产量的90%以上。中国的贝类养殖历史悠久,距今2000多年前就有牡蛎养殖的记载,但规模化养殖始于20世纪70年代,这主要得益于贝类的苗种繁育技术得到了提高;随后,贻贝、扇贝、牡蛎等多种贝类的苗种繁育和人工采苗技术的建立,推动了贝类产业的迅速发展。进入21世纪,贝类养殖规模不断扩大,养殖种类不断增加,养殖产量大幅度提高。中国海岸线长度为1.8万公里,从北到南跨越辽宁、河北、天津、山东、江苏、上海、浙江、福建、广东、广西和海南11个省(直辖市),大多数海域都适合贝类养殖,因气候差异显著,贝类分布具有明显地域性。中国贝类养殖方式主要包括筏式养殖和底播养殖,前者主要养殖种类包括牡蛎、扇贝、贻贝等;后者主要养殖种类包括菲律宾蛤仔、毛蚶、文蛤、虾夷扇贝等。本文分别以长牡蛎、厚壳贻贝为代表介绍了筏式养殖贝类的苗种生产和养殖过程;以菲律宾蛤仔和泥蚶为例介绍了滩涂贝类的苗种繁育和养殖过程。

Macrobenthos is widely used as an indicator of ecological health in marine monitoring and assessment. The present study aimed to characterize the interrelationships between the distribution of the macrobenthos community and environmental factors near Xiaoqing Estuary, Laizhou Bay. Responses of species richness to environmental factors were studied using the generalized additive model (GAM) and the Margalef diversity index (d_M) as indicators of species diversity instead of individual indicator species. Six factors were selected in the optimal model by stepwise regression: sediment factors (organic matter, phosphate, nitrate nitrogen, and ammonium nitrogen) and water factors (salinity, and ammonium nitrogen). The response curves generated by the GAM showed a unimodal relationship among taxa diversity, salinity in water, and sediment organic matter. d_M was positively correlated with ammonium nitrogen in water and was negatively correlated with phosphate in the sediment. The model optimized by forward stepwise optimization explained 92.6% of the Margalef diversity index with a small residual (2.67). The model showed good performance, with the measured d_M strongly correlated with the predicted d_M (Pearson R² = 0.845, p < 0.05). The current study examined the combined influence of multiple eco-factors on macrobenthos, and the Margalef diversity index of macrobenthos was predicted by the GAM model in a salinity-stressed estuary.

The providers of butyric acid, Clostridium butyricum (CB), sodium butyrate (SB), and tributyrin (TB), have been extensively studied as aquafeed additives in recent years. However, no comparative study has been reported on the probiotic effects of CB, SB, and TB as feed additives on sea cucumber (Apostichopus japonicus). A 63‐day feeding trial was performed to assess the effects of dietary live cells of C. butyricum (CB group, the basal diet supplemented with 1% CB), sodium butyrate (SB group, the basal diet supplemented with 1% SB), and tributyrin (TB group, the basal diet supplemented with 1% TB) on the growth, non‐specific immunity, and intestinal microbiota of A. japonicus with a basal diet group as the control. Results indicated that all three additives considerably increased A. japonicus growth, with dietary CB having the optimal growth‐promoting effect. Of the seven non‐specific enzyme parameters measured in coelomocytes of A. japonicus (i.e., the activities of phagocytosis, respiratory burst, superoxide dismutase, alkaline phosphatase, acid phosphatase, catalase, and lysozyme), dietary CB, SB, and TB considerably increased the activities of six, five, and six of them, respectively. The immune genes (Aj‐p105, Aj‐p50, Aj‐rel, and Aj‐lys) expression in the mid‐intestine tissues of A. japonicus was significantly increased by all three additives. The CB group had the highest expression of all four genes. Additionally, the relative expression of Aj‐p105, Aj‐p50, and Aj‐lys genes was significantly up‐regulated in the three additive groups after stimulation with inactivated Vibrio splendidus. Dietary CB enhanced the intestinal microbial diversity and richness in A. japonicus while dietary TB decreased them. Meanwhile, dietary CB, SB, and TB significantly enhanced the abundance of Firmicutes, unclassified_f_Rhodobacteraceae, and Proteobacteria, respectively, while dietary CB and SB reduced the abundance of Vibrio. Dietary CB and SB improved the stability of microbial ecosystem in the intestine of A. japonicus. In contrast, dietary TB appeared to have a negative effect on the stability of intestinal microbial ecosystem. All three additives improved the intestinal microbial functions associated with energy production and immunity regulation pathways, which may contribute directly to growth promotion and non‐specific immunity enhancement in A. japonicus. Collectively, in terms of enhancing growth and non‐specific immunity, as well as improving intestinal microbiota, dietary live cells of C. butyricum exhibited the most effective effects in A. japonicus.