Effects of water depth and substrate color on the growth and body color of the red sea cucumber,Apostichopus japonicus

Three color variants of the sea cucumber,Apostichopus japonicus are recognized,the red one is highly valued in the market. When the red variant is cultured in ponds in China,its body color changes from red to celadon in 3–6 months. The effects of water depth and substrate color on the growth and body color of this animal were investigated. Juveniles of red A. japonicus were cultured in cages suspended at a range of water depths(20,50,100,150 and 200 cm). The specific growth rate of red sea cucumbers was significantly higher in animals cultured at deeper water layers compared with those grown at shallowers. Body weights were greatest for sea cucumbers cultured at a depth of 150 cm and their survival rates were highest at a depth of 200 cm. A scale to evaluate the color of red sea cucumbers(R value) was developed using a Pantone standard color card. All stocked animals in the 9-month trial retained a red color,however the red body color was much more intense in sea cucumbers cultured at shallower depths,while animals suspended in deeper layers became pale. In a separate trial,A. japonicus were cultured in suspended cages with seven different colored substrates. Substrate color had a significant effect on the growth and body-color of red A. japonicus. The yield were greatest for A. japonicus cultured on a yellow substrate,followed by green > white > orange > red > black and blue. All sea cucumbers in the 7-month trial retained a red color,although the red was most intense(highest R value) in animals cultured on a blue substrate and pale(lowest R value) for animals cultured on a green substrate.

公车拍卖应注意的几个问题

公务用车制度改革,是最受老百姓关注的政务改革举措之一。中纪委在二次全会上,提出了各地积极稳妥地进行公务用车的改革要求。各省、市闻风而动,相继出台了《实施公务用车制度改革的意见》,公车改革的浪潮在全国各地掀起。公车处置的最好途经是公开拍卖,在实施公车拍卖的过程中要对每个环节进行了认真的审核,并采取了相应的对策措施。