外源性磷脂对脊尾白虾卵巢发育及组织营养素积累的影响

磷脂有助于甲壳动物生长和繁殖,但其对脊尾白虾亲体卵巢发育及营养素积累的作用尚不清楚。为此,探究了饲料中不同磷脂水平(0%、1%、2%、4%和6%)对脊尾白虾亲虾卵巢发育、营养物质积累及抗氧化能力的影响。结果表明,1%、2%和4%磷脂组的卵巢蛋白质和磷脂含量超过6%磷脂组,且高于肝胰腺中含量,表明适宜磷脂会促进性腺发育及相关营养物质转运和积累。其中,1%磷脂组不仅能促进虾体LC-PUFA,尤其是ARA等脂肪酸积累,还提高了血淋巴SOD和CAT酶活力,有助于改善虾的抗氧化应激能力。综上可知,适合脊尾白虾亲体性腺发育和营养积累的最适磷脂添加量为1%。

Phenotypic correlations of somatic and gonad traits of sea urchins Glyptocidaris crenularis in two sampled periods:first insight into its breeding and aquaculture

Prior knowledge of the correlations among commercially important traits in Glyptocidaris crenularis can be used to guide development of breeding and aquaculture programs for this species.We evaluated the phenotypic correlations between somatic and gonadal traits in G.crenularis during two sample periods(October 2010 and April 2011).The coeffi cients of variation(CV%)for body weight(BW),redness(a*),yellowness(b*),gonad wet weight(GW),and gonad index(GI)were>20% in both periods,while those of other traits were very low.GW was signifi cantly correlated with somatic traits(diameter,height,and body weight)in both periods,although the correlation coeffi cients ranged from 0.473 to 0.636(P<0.01).Gonad moisture content(GC),a*,and lightness(L*)were not signifi cantly correlated with somatic traits(P>0.05).The color trait b* was negatively correlated with somatic traits(test diameter,test height,and body weight)during the period when the gonads were well developed(April 2011,P<0.05).We observed little difference in the nature of the phenotypic correlations between the two sample periods.The high variation in the somatic and gonad weight traits in G.crenularis suggests there is considerable potential for selective breeding.However,our results suggest that gonad quality traits cannot be selected indirectly by selecting for body weight.Our study provides an insight into the method for improving the breeding and aquaculture of G.crenulari.

Assessment of negative phototaxis in long-term fasted Glyptocidaris crenularis:a new insight into measuring stress responses of sea urchins in aquaculture

A cost-effective method was designed to measure the behavioral response of negative phototaxis to high-intensity illumination in the sea urchin Glyptocidaris crenularis.Ninety sea urchins were randomly and equally divided into two aquaculture environment groups:a fasted group,which was starved during the experiment,and a fed group.After 10 months,the total mortality of each group was recorded.Then,15 sea urchins were randomly selected from each group and behavioral responses to high-intensity illumination were investigated for each sea urchin.After the behavioral experiment,body measurements of the trial sea urchins were taken.The results reveal that food deprivation significantly affected test diameter(P<0.01),body weight(P<0.01),gonad weight(P<0.01),and gut weight(P<0.01).Furthermore,food deprivation also affected negative phototaxis behaviors of time to rapid spine movement(P<0.01),time to the 1 cm position(P<0.05),and walking distance in 300 s(P<0.01),but not time to body reaction(P>0.05).The mortality rates of fasted and fed urchins were 6.7%and 0%,respectively.The present study provides evidence that food deprivation has a significant effect on phenotypic traits and behavioral responses to high-intensity illumination in the sea urchin G.crenularis.With this method,environmental stressors can be easily detected by measuring proper optional indicators.This study provides a new insight into measuring stress responses of sea urchins in aquaculture.However,further studies should be carried out to understand more environmental factors and to compare this potential behavioral method with immune,physiological,and epidemiological approaches.

Correlation analyses of covering and righting behaviors to fitness related traits of the sea urchin Glyptocidaris crenularis in different environmental conditions

Complex marine benthic environments shape a number of ecologically important behaviors in sea urchins, including covering and righting behaviors. The present study correlated covering and righting behaviors to a series of fi tness-related traits in sea urchins. Righting response time of Glyptocidaris crenularis was signifi cantly positively correlated with body size, but signifi cantly negatively correlated with food consumption. Covering behavior was not signifi cantly correlated with test diameter, test height or body weight, but covering response time was negatively correlated with body weight. A signifi cantly negative correlation was found between righting response time and covering response time. Glyptocidaris crenularis showed a signifi cantly positive correlation in covering response time with and without exposure to poured sand, but no signifi cance in covering ability(number of shells used to cover). The present study provides new insight into internal mechanisms and evolutionary drives of covering and righting behaviors of sea urchins.