双齿围沙蚕昼夜代谢规律的初步研究

Preliminary studies on the diurnal variation of metabolism of Perinereis aibuhitensis

在20℃下测定了双齿围沙蚕的常规代谢和标准代谢的昼夜变化规律。按沙蚕体湿重分别设置S[0.50±0.05g]、M[0.90±0.05g]、L[1.50±0.05g]3个组,投喂人工合成的牙鲆饵料,结果表明:(1)常规代谢和标准代谢均随体重的增加而降低,符合幂函数方程R=aWb,b值分别为-0.5988、-0.4817;(2)在标准代谢的昼夜变化中,S、M、L各组表现出相同的规律,即夜间代谢增强,白天相对低缓;(3)对双齿围沙蚕常规代谢和标准代谢昼夜变化的比较表明,S、M和L组特殊动力代谢的峰值分别为3.936、1.5222和1.2853mg·(g·h)-1,持续时间相近,S、M、L总耗能分别为:271.62、73.56和70.56J·g-1。

The diurnal variations of standard metabolism (SM) and routine metabolism (RM) of Perinereis aibuhitensis were determined in feeding commercial Paralichthys oliveaceus diet at 20℃. The worms used in this experiment were collected from seaside of Zhuanghe, Dalian, Liaoning province. Worms were grouped according to the wet body weight [S 0.50±0.05g,M 0.90±0.05g,L 1.50±0.05g]. The relation between dry body weight (W, g) and wet body weight (W, g) is equivalent to: W=0.2168wt-(0.0548) (R^2=0.9833, n=43). SM and RM were determined under the oxygen determining apparatus by flowing water system whose water was filtered with a salinity of 31-32. The Winkler method and Nestle method were adopted to study the oxygen consumption rate (R) and the ammonia excretion rate (AE). By comparing RM with SM, the specific dynamic metabolism (SDA) of P. aibuhitensis was studied. The results were as follows: (1) SM and RM of P. aibuhitensis decreased with the body weight increasing. It can be described as R= aW^b, where W is dry body weight, R is oxygen consumption rate, a and b were parameters (a were (0.3725),(0.2743),b were-0.4817, -0.5988 respectively). SM and RM were significantly affected by dry body weight ((F=)16.449,P<(0.001); F=19.327,P<0.001). And AE were significantly affected by dry body weight too (F=4.855,P=(0.014); F=(4.003),P=0.028).4 (2) Each group had the same changeable rule of standard metabolism. The averages of SM in S、M and L groups were (1.0248) mg·(g·h)^(-1),(0.7285) mg·(g·h)^(-1) and 0.5019 mg·(g·h)^(-1) respectively. But it was higher in night than that at day.SM in night of three groups were as 2.17,1.42 and 1.87 times as at day. This might be explained as the activity of P.aibuhitensis was correlated with illumination. The AE of S,M,L in starved state changed little too, because of the starvation threaten the protein in worm tissue was consumed in metabolism at the end of experiment, so the AE was increasing slowly after experiment beginning 18h,24h,24h respectively. (3) RM in each group changed more than that of SM in this experiment.The RM of S,M and L went to the peak after experiment beginning 21-24h. The peak values of SDA in S,M,L were 3.936 mg·(g·h)^(-1),(1.5222) mg·(g·h)^(-1) and 1.2853 mg·(g·h)^(-1) respectively, as 4.84,1.71 and 2.29 times as their SM. By comparing the diurnal variations of SM with RM metabolism of three groups of P. aibuhitensis, results showed that SDA of the three groups, started at the same time, namely after feeding 15h, persisted about 12h.The energy expenditure of SDAwere 271.62 J·g^(-1),73.56 J·g^(-1) and (70.56) J·g^(-1) respectively. The ammonia excretion rates of S,M,L in satiation state changed significantly during the experiment. The peak values of the wave of satiation state were 9.2176 μmol·(g·h)^(-1),6.5935 μmol·(g·h)^(-1),2.6866 μmol·(g·h)^(-1) respectively, as (2.82),4.15 and 1.67 times as their starvation state,accordingly the durations were 9h,9h,12h. The wave of each group were started later than its oxygen consumption rate, and that of S group started after feeding 24h, and M group was 21h, L group was 15h. The wave energy expenditure of S,M,L were 0.9729 J·g^(-1),4.9600 J·g^(-1) and 4.0773 J·g^(-1) respectively. This paper preliminarily concluded that SDA of P.aibuhitensis decreased with dry body weight increasing, that is, small worms metabolize much more actively than large worms.