The effect of different macroalgae on the growth of sea cucumbers (Apostichopus japonicus Selenka)

摘要

Sea cucumber Apostichopus japonicus is an important aquaculture species, especially in northern China (Chen 1990), and ingests sediment containing organic matter (Moriarty 1982; Zhang, Sun & Wu 1995). In a semi-intensive culture, sea cucumbers are fed formulated diets, which are commonly made of macroalgal powder and sea mud (Chang, Yi & Mu 2003). The algae Sargassum thunbergii and Sargassum polycystum are the most commonly used and high-quality food for sea cucumbers. With the expansion of sea cucumber farming, however, the resources of S. thunbergii and S. polycystum have decreased dramatically. Their price has increased in recent years (Yuan 2005). In order to meet the demand of sea cucumber farming in northern China, it is necessary to find other local substitutes for these macroalgae. The alga Laminaria japonica, with its extensive sources and low price in China (Yuan 2005), is widely used in the aquaculture of abalone (Qi, Liu, Li, Mao, Jiang, Zhang & Fang 2010), sea urchin (Chang & Wang 1997; Agatsuma 2000). Zhu, Liu, Leng, Qu, Wang, Xue and Sun (2007) also reported that fresh kelp L. japonica could be a part of the diet of sea cucumber. Laminaria japonica holdfast is a by-product of kelp processing, but it contains many bioactive substances (Bu, Chen, Wang, Zhou, Zheng & Lin 2009). The feasibility of L. japonica for the diet of sea cucumbers needs to be investigated.