Effects of stocking density and body physical contact on growth of sea cucumber,Apostichopus japonicus

Abstract

The present study was conducted to investigate the effects of physical contact on the growth of Apostichopus japonicus through various stocking densities, group culture and physical isolation culture. The results showed that the specific growth rates (SGR), the feed conversion efficiencies and the energy used for growth of the animal decreased with the increase in stocking density, while the coefficient of variations (CV) in group culture treatments increased. In high density treatments (4, 6 ind./40 L), the SGRs in isolated culture treatments were not different to those in group culture treatments of the same density, however, the CVs in the latter (58.0% and 60.4%, respectively) were significantly higher than those in the former (37.8% and 35.8%, respectively). The CV difference between group one and isolated one of the same density (20.2% and 24.7%, respectively) was less than that in single individual culture (32.7%), indicating that the effect of physical contact on growth variation was weaker than that of genetic factor. This study proved that the individual growth variation in sea cucumber resulted mainly from genetic factor and physical contact, while some chemical mediator might also be the factor affecting the growth rate of sea cucumber.

Dietary supplementation of red alga Pyropia spheroplasts on growth, feed utilization and body composition of sea cucumber, Apostichopus japonicus (Selenka)

“…FCE of the juvenile sea cucumber fed Sargassum thunbergii diet showed the highest value at 16°C (An et al., ) which is similar to the present experiment. Higher FCE value was recorded using the dry pellets for juvenile sea cucumber two individuals in a tank, and the FCE value decreased with increasing the density (Pei et al., ). The nutritional composition, taste and palatability of feed ingredients can influence feed intake and feed efficiency.…”

“…Knowledge of the dietary requirements is important for commercial aquaculture. Studies have examined the nutritional requirements (Choi, Seo & Lee, ; Okorie et al., , ; Seo & Lee, ), feed ingredients (Liu, Dong, Tian, Wang & Gao, ; Seo, Shin & Lee, ,b; Shi, Dong, Wang, Gao & Tian, ; Shi et al., ; Slater, Jeffs & Carton, ; Yuan et al., ), diet formation (Xia et al., 2013), culture technology (Pei, Dong, Wang, Gao & Tian, ; Sui, ), water quality (An, Dong & Dong, ; Xie, Zhao & Yang, ; Yuan, Yang, Wang, Zhou & Gabr, ) of sea cucumber. Plant‐based ingredients, especially macroalgae, such as brown alga Sargassum thunbergii (Mertens ex Roth), are considered as a necessary part of the diet of A. japonicus (Xia et al., ).…”

Transcriptome analysis of the sea cucumber (Apostichopus japonicus) with variation in individual growth

“…Dong et al reported that individual growth variation of sea cucumber increased with the increase of stocking densities, whereas no significant differences in variation were found when the density was over 30 inds [5]. Pei et al gave a similar result, which showed that physical contact caused by stocking density could affect the individual growth variation of sea cucumber [6]. However, the genetic factor was thought to be more effective than stocking density [6].…”

“…Pei et al gave a similar result, which showed that physical contact caused by stocking density could affect the individual growth variation of sea cucumber [6]. However, the genetic factor was thought to be more effective than stocking density [6]. Liang et al reared sea cucumber individually to eliminate possible effects of environmental differentiation, such as social interaction, stocking density, etc.…”

Viability of a bottom-set tray ocean nursery system for Holothuria scabra Jaeger 1833

“…Understanding the factors that affect growth and survival of juveniles is important in optimizing a culture production system. Stocking density is one of the most critical factors affecting the growth of many cultured marine organisms (Battaglene, Seymour & Ramofafia, ; Daly, Swingle & Eckert, ; Dong et al., ; Nga et al., ; Pei, Dong, Wang, Gao & Tian, ; Zhang et al., ). High stocking density affects growth directly through increased competition for food and space and indirectly through degradation of water quality (Huchette, Koh & Day, ; Nga et al., ).…”