急性高渗胁迫对中华绒螯蟹雄蟹组织中可溶性蛋白质、血蓝蛋白、血糖与肝糖原含量的影响

实验以淡水(0.3‰)处理组为对照,研究了急性高渗胁迫(盐度16‰和30‰)对中华绒螯蟹(Eriocheirsinensis)雄蟹血淋巴和肝胰腺中可溶性蛋白质、血蓝蛋白、血糖及肝糖原含量的影响。结果显示,与对照组相比,进入16‰及30‰盐度后,蟹的血淋巴中可溶性蛋白质含量从6—48h显著降低(P<0.05),至72h时显著增加(P<0.05),而机体肝胰腺的可溶性蛋白质含量从12h开始至96h显著降低(P<0.05);血蓝蛋白含量在前24h显著降低(P<0.05),48h开始显著升高(P<0.05);肝糖原含量在6—96h与对照组相比有显著的降低(P<0.05);16‰盐度组蟹的血糖含量在24—48h时显著下降(P<0.05),到72h开始逐渐恢复(P>0.05),而30‰盐度组其血糖含量早在6—12h时就有显著的下降(P<0.05),到24h则开始逐渐升高。研究表明,在急性盐度胁迫下,糖类和蛋白质对中华绒螯蟹渗透压调节起重要的作用,其优先利用糖类的分解获得所需的能量,其中盐度越高,机体内葡萄糖的消耗越快,血糖水平的恢复也相应较快。对蛋白质的利用稍次之,机体可利用蛋白质的分解获得其渗透压调节的效应物游离氨基酸以维持渗透压平衡。     

水体盐度对中华绒螯蟹成体雄蟹渗透压调节和生理代谢的影响

为研究长期不同水体盐度对中华绒螯蟹(Eriocheir sinensis以下简称河蟹)成体雄蟹渗透压调节和生理代谢的影响, 在不同水体盐度条件下(0、6、12和18)对河蟹雄体进行为期60d的养殖实验, 并分别检测其渗透调节及生理代谢相关指标。结果显示: (1)血清渗透压、Na+、Mg2+和Cl-含量随水体盐度上升而显著上升(P0.05), K+和Ca2+含量有上升趋势, 但各盐度组差异不显著(P0.05); 无论何组雄蟹, 其血清渗透压均显著高于对应的水体渗透压; (2)0组雄蟹后鳃Na+/K+-ATP酶活性显著高于其他组(P0.05), 其他各组间差异不显著(P0.05); (3)就血清生理代谢指标而言, 12组雄蟹血清中甘油三酯(TG)含量显著高于其他组(P0.05), 而尿酸(UA)、葡萄糖(Glu)、丙二醛(MDA)含量和超氧化物歧化酶(SOD)活性相对较低; 所有组尿素(Urea)、碱性磷酸酶(ALP)含量差异不显著(P0.05); (4)就肝胰腺生理代谢指标而言, 6组肝胰腺MDA含量和-谷氨酰转肽酶(-GT)活力最低, 12组酸性磷酸酶(ACP)和-GT活性显著高于其他盐度组(P0.05)。因此, 适当提高水体盐度可提高河蟹成体雄蟹的血清渗透压及其主要离子含量, 同时降低其后鳃中Na+/K+-ATP酶活性。肝胰腺和血清代谢指标暗示12盐度组雄体的代谢水平相对较低, 具有较强的免疫性能和抗氧化能力。     

长江口中华绒螯蟹放流亲蟹对环境的生理适应

按回捕日期取样测定长江口中华绒螯蟹亲蟹标志放流前后血清与肝胰腺的生理指标, 初步研究了放流亲蟹对长江口环境的生理适应过程。结果表明, 在放流后6d, 亲蟹肝胰腺超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性以及血清甘油三酯(TG)和血蓝蛋白含量均降低, SOD、CAT和TG在放流后9d达到较低水平, 其中SOD活性和TG含量较放流前显著降低(P<0.05); 肝胰腺酸性磷酸酶(ACP)以及血清谷丙转氨酶(ALT)、谷草转氨酶(AST)、碱性磷酸酶(ALP)、总蛋白质(TP)、白蛋白(ALB)、总胆固醇(TC)和肌酐(CREA)水平在放流后总体呈现先升高后降低的趋势; 在放流后79d, 肝胰腺SOD、CAT、ACP与血清ALP、ALT、AST活性均恢复至放流前水平(P>0.05), 而血清TP、血蓝蛋白、ALB、TC、TG、CREA含量较放流前均显著降低(P<0.05)。综合各项指标表明, 中华绒螯蟹亲蟹在放流后6d内出现免疫力下降、代谢增强等反应, 放流22d后亲蟹各项机能逐步恢复, 并在70d后接近或达到放流前水平。建议今后放流前对亲蟹进行环境适应性驯化, 以便提高亲蟹增殖放流效果。     

中华绒螯蟹在不同pH下氨氮排泄和血淋巴含氮成分的变化

为研究不同环境pH对中华绒螯蟹(Eriocheir sinensis)氮排泄的影响,将性成熟的中华绒螯蟹置于pH 4.5、6.0、7.5、9.0和10.5的环境中,24h后测定血淋巴中不同含氮成分的变化.结果表明,环境pH从4.5到9.0,中华绒螯蟹的氨氮排泄无显著变化,当pH升高到10.5时,氨氮排泄受到显著抑制;同时环境pH的升高还导致血淋巴pH上升,在pH 10.5时,血淋巴氨氮、尿素氮和尿酸的含量也显著上升分别达到(5.90±0.61) μg/mL、(2.47±0.14)μg/mL和(0.096±0.002)μmol/mL.实验结果还显示,高pH环境影响中华绒螯蟹的蛋白质和氨基酸的代谢水平,降低血淋巴总蛋白和血蓝蛋白的含量,而游离氨基酸含量显著增加,它们的变化可能同机体的氨中毒解毒机制有关.     

饲料中添加合成虾青素对中华绒螯蟹成体雌蟹性腺发育、色泽和抗氧化能力的影响

采用在基础饲料中分别添加0、130和260 mg/kg的合成虾青素配制成3种粗蛋白和粗脂肪含量分别为42%和16%的等氮等脂的中华绒螯蟹(Eriocheir sinensis)育肥饲料(分别记为饲料1、2和3), 以中华绒螯蟹商业育肥饲料作为饲料4, 分别投喂4组雌蟹(每个饲料组3个重复水槽, 每个水槽中12只蟹), 进行为期60d的室内养殖实验, 以探讨添加合成虾青素对中华绒螯蟹成体雌蟹性腺发育、色泽及抗氧化能力的影响。结果显示: (1)实验进行到30d和60d, 在饲料中添加虾青素对雌体肝胰腺指数(HSI)和性腺指数(GSI)均无显著影响(P>0.05)。(2)性腺、肝胰腺和头胸甲中的总类胡萝卜素含量和红度值(a值)均以饲料3组最高, 性腺亮度值(L值)和黄度值(b值)以饲料1组最高(P<0.05); 饲料2组头胸甲的b值最高, 饲料1组最低(P<0.05)。(3) 饲料1组中华绒螯蟹血清过氧化物酶(POD)活性显著高于其他组, 饲料4组的过氧化氢酶(CAT)、谷胱甘肽还原酶(GR)、乳酸脱氢酶(LDH)、总抗氧化能力(T-AOC)、丙二醛(MDA)和乳酸(LD)含量最高(P<0.05); 肝胰腺中的SOD、T-AOC、GSH-Px和GR活性均以饲料1组最高, 饲料2组最低(P<0.05)。(4) 饲料2组血清酸性磷酸酶(ACP)活性和血蓝蛋白(Hc)含量显著高于其他组, 其余各组间差异不显著。血清中的碱性磷酸酶(ALP)和γ-谷氨酰转移酶(γ-GT)活性和一氧化氮(NO)含量均以饲料4组最高(P<0.05), 肝胰腺中的ACP、ALP和γ-GT活性以饲料1组最高。综上, 在育肥饲料中添加合成虾青素对成体雌蟹性腺发育无显著影响, 但可显著提高头胸甲、肝胰腺和卵巢中的类胡萝卜素总量、色泽和抗氧化能力, 建议雌蟹育肥饲料中合成虾青素的含量为90 mg/kg左右。     

中华绒螯蟹对Pb和Cd的富集与释放特性

应用生物富集双箱动力学模型模拟了中华绒螯蟹(Eriocheir sinensis)分别在Pb浓度为0.25、0.50、0.75mg/L,Cd浓度为0.025、0.050、0.075mg/L的单一水环境中暴露时,蟹鳃、肝胰腺、肌肉和血淋巴对Pb和Cd的生物富集与释放实验,并通过非线性拟合得到中华绒螯蟹对Pb和Cd的富集速率常数k1、排出速率常数k2、生物富集系数BCF、生物半衰期B1/2、富集平衡时生物体内Pb和Cd含量CAmax等动力学参数。结果表明:(1)中华绒螯蟹对Pb和Cd具有明显的富集,蟹鳃、肝胰腺和肌肉中Pb和Cd的含量与富集时间和水环境中Pb和Cd暴露浓度表现出了很好的正相关,血淋巴在富集阶段没有明显的规律。理论平衡状态下鳃、肝胰腺和肌肉中Pb和Cd含量CAmax随着暴露浓度的增大而增大,且成正相关。(2)Pb和Cd在中华绒螯蟹组织器官中的富集具有选择性,开始实验前,Pb在中华绒螯蟹体内的的分布规律为:肝胰腺>鳃>肌肉>血淋巴;Cd的分布规律为:鳃>肝胰腺>血淋巴>肌肉。在实验浓度的Pb和Cd水环境中暴露16d后,Pb的分布规律为:鳃>肝胰腺>肌肉>血淋巴;Cd的分布规律为:肝胰腺>鳃>肌肉>血淋巴。(3)中华绒螯蟹对Pb和Cd的生物富集和释放都较缓慢。经过16d的生物富集,各组织器官中Pb和Cd的含量均未达到稳态平衡。Pb和Cd在组织器官中的生物富集系数(BCF)范围分别为5-51和6-3148,中华绒螯蟹对Cd的富集能力明显高于Pb(P1/2)范围分别为4-9d和8-57d,中华绒螯蟹对Cd的排出能力明显低于Pb。       

投喂不同油脂饲料对中华绒螯蟹免疫、代谢及耐低氧性能的影响

为研究饲料中添加鱼油和豆油对中华绒螯蟹(Eriocheir sinensis)成蟹生长、免疫、代谢和耐低氧性能的影响,配制了添加不同比例鱼油和豆油的3种蟹用饲料,添加3%鱼油饲料组、3%豆油饲料组、3%鱼油和豆油混合组(1∶1,质量比),将其分别投喂中华绒螯蟹115 d后测量蟹体重、壳长和壳宽的变化,再将其放入溶解氧(dissolved oxygen,DO)为(9.06±0.06)mg/L和(2.57±0.44)mg/L的水体中,测定其免疫、代谢指标及耐低氧性能的变化。结果发现:投喂添加3种不同油脂饲料的中华绒螯蟹各组间体重无显著性差异;低氧胁迫对中华绒螯蟹代谢指标影响较大;添加鱼油和豆油混合油饲料组中华绒螯蟹血细胞密度、血蓝蛋白含量及超氧化物歧化酶、酸性和碱性磷酸酶、乳酸脱氢酶的活性都为最高,说明鱼油与豆油混合添加对中华绒螯蟹免疫和抗氧化能力有促进作用,并增加其耐低氧能力。     

盐酸环丙沙星在中华绒螯蟹体内药物代谢动力学研究

应用反向高效液相色谱法对盐酸环丙沙星在中华绒螯蟹雄、雌蟹血淋巴与肌肉内的代谢规律进行了研究。肌肉注射给药后血淋巴中盐酸环丙沙星的浓度立即达到峰值 ,药物开始向肌肉等组织中运转 ,血药浓度在 1h内迅速下降 ,而肌肉中的浓度达到峰值 ;此后无论是血淋巴还是肌肉中的盐酸环丙沙星浓度均缓慢下降 ,到第 12 0h雌、雄蟹中盐酸环丙沙星的浓度均在 1μg·mL-1(g-1)以下 ,到 2 16h均不能检出。研究表明 :中华绒螯蟹血淋巴中盐酸环丙沙星的药物浓度可用一级吸收二室开放模型描述 ,雄、雌蟹的消除半衰期 (T1/ 2 β)分别为 40 .34± 1.48h和 2 2 .0 7±0 31h ;中华绒螯蟹的性别对盐酸环丙沙星在其体内的代谢有较大的影响。     

低盐度海水和淡水对中华绒螯蟹性腺发育及交配行为的影响

研究了低盐度海水(盐度为15)和淡水(盐度为0)对中华绒螯蟹(Eriocheir sinensis,以下简称河蟹)性腺发育及交配行为的影响,并比较了河蟹交配和产卵前后的性腺指数及肝胰腺指数的变化。实验分为4组,分别为低盐度海水雌蟹组、淡水雌蟹组、低盐度海水雄蟹组和淡水雄蟹组。结果表明,(1)各组河蟹的成活率均在80%左右,无显著差异(P>0.05);(2)实验第15天、30天和45天时,低盐度海水雌蟹组的卵巢指数显著高于淡水雌蟹组(P<0.05),低盐度海水雄蟹组的性腺指数也略高于淡水雄蟹组,但差异不显著(P>0.05);(3)实验第30天时,低盐度海水雌蟹组的肝胰腺指数显著低于淡水雌蟹组(P<0.05),其余采样时间两组雌体间或两组雄体间的肝胰腺指数差异不显著(P>0.05),实验期间,两组雌体的肝胰腺指数均显著下降(P<0.05);(4)实验第45天,低盐度海水雌蟹组和雄蟹组实验个体全部能够交配,有66.7%的低盐度海水雌蟹组的个体交配后2 d内产卵,淡水雄蟹组有部分个体在低盐度海水中有发情行为;(5)低盐度海水组,雌蟹产卵后和雄蟹交配后的性腺指数均显著下降(P<0.05),但肝胰腺指数下降不显著(P>0.05)。     

盐度变化对克氏原螯虾渗透调节影响机制的初步研究

本文研究了克氏原螯虾在盐度变化下血淋巴渗透压、鳃丝Na+-K+-ATPase活力和生物胺的变化过程和特征。结果显示：盐度变化（0－20‰）对克氏原螯虾血淋巴渗透压、鳃丝Na+-K+-ATPase活力和生物胺含量影响显著(p<0.05),而对照组无明显变化。在实验时间内各处理组血淋巴渗透压随盐度变化增大而升高,1－2d后趋于稳定,鳃丝Na+-K+-ATPase活力逐渐降低,6d后保持稳定,且渗透压正相关性,酶活力与盐度呈负相关性;各处理组在实验时间内血淋巴和鳃丝多巴胺、去甲肾上腺素、5-羟色胺含量均呈峰值变化,血淋巴中多巴胺、5-羟色胺含量分别在1d和3d时达到最小值和最大值,且变化过程分别与盐度变化值呈负和正相关性,并分别在6d和9d后趋于稳定,而各处理组的NE含量（除盐度为4的处理组）在0.5d内迅速升高,0.5－3d内略有波动,然后呈下降趋势,至15d时保持稳定;各处理组鳃丝多巴胺、去甲肾上腺素和5-羟色胺含量均于2d时达到最大值,且变化过程均与盐度变化值呈正相关性,均在9d后趋于稳定;稳定后各处理组血淋巴和鳃丝生物胺含量均与对照组无显著性差异。这些结果表明,在外界盐度变化下生物胺作为一种神经内分泌因子,在甲壳动物的渗透压调节过程中发挥重要作用,可引发甲壳动物产生的渗透调节过程,如激活鳃丝已有的Na+-K+-ATPase活力、调节血淋巴渗透压效应物含量以适应外界环境的变化。     

Hydrochlorothiazide, amiloride and tolmetin in the treatment of diabetes insipidus of Brattleboro rats

To test the effects of hydrochlorothiazide (HCTZ) alone and in combination with amiloride or tolmetin in the treatment of nephrogenic diabetes insipidus, metabolic studies of 12 days each were carried out in 36 male, Brattleboro rats. They were divided into five groups as follows: (A) controls; (B) high dose HCTZ at 6 mg/rat/day; (C) low dose HCTZ at 3 mg/rat/day; (D) HCTZ identical to (C) but with addition of amiloride at 0.6 mg/rat/day; (E) HCTZ identical to (C) but with addition of tolmetin at 40 mg/rat/day. The immediate response to treatment was a significant increase in urinary sodium excretion from mean values (mEq/kg/day) of less than 11 to values higher than 13, except group E with mean value of 12. There was marked increase in urinary potassium excretion (mEq/kg/day), from mean control value of 15.5 to 21.5, 20.8, 18.5 and 17.7 in groups B, C, D and E, respectively. During the last three days of the study, mean urine osmolality (Uosm) and free water reabsorption (TCH2O) increased significantly: [formula: see text]. These indices were higher in groups B, D and E than in group C. Serum osmolality decreased only in groups B, C and D but not in the HCTZ-tolmetin groups. Similarly, serum sodium concentration was significantly lower in groups B, C and D compared to the control and the HCTZ-tolmetin groups. Serum potassium concentration was reduced in all the treated groups, but in both the groups treated with HCTZ-amiloride and HCTZ-tolmetin, the reduction was smaller than the one observed in the high-HCTZ treated group.(ABSTRACT TRUNCATED AT 250 WORDS)     

Physiological responses to salinity changes of the isopod Idotea chelipes from the Baltic brackish waters

Survival, haemolymph osmolality and the specific metabolic rate of the isopod Idotea chelipes from the brackish waters of the southern Baltic Sea (salinity 7 psu) were investigated after acclimation to different salinities in the range of 3-30 psu keeping other parameters constant (T=15 degrees C, full air saturation). Haemolymph osmolality of I. chelipes increased from 379+/-33 mmol kg(-1) at 3 psu to 935+/-12 mmol kg(-1) at 30 psu. In the salinity range of 3-11 psu I. chelipes exhibited a hyperosmotic pattern of haemolymph regulation, whereas from 14 to 25 it behaved like an osmoconformer. Isoosmosis occurred at 28.5 psu (920 mmol kg(-1)). The specific metabolic rate of I. chelipes was significantly (P<0.05) related to salinity, with maximum (2.4+/-0.8 J g(-1) wm h(-1)) and minimum values (0.6+/-0.3 J g(-1) wm h(-1)) at 7 and 20 psu, respectively. The changes in the specific metabolic rate and in the difference between the osmolality of haemolymph and external medium were significantly correlated for I. chelipes (P<0.05). Rates of change per salinity unit were, however, unequal varying according to salinity transition. These differences indicate that osmotic adjustment may be a more or less costly in terms of energy according to salinity.     

The salinity tolerance of the invasive golden apple snail (Pomacea canaliculata)

We exposed snails of an invasive species of golden apple snail (Pomacea canaliculata) to five artificial sea water treatments at salinity levels of 0, 5, 10, 15 or 20 parts per thousand (ppt) to assess their salinity tolerance. We observed the behaviour, heart rate, total haemocyte counts, haemolymph ionic concentration and Na⁺/K⁺-ATPase activity in the mantle at 0, 12, 24, 48, 72 and 96 h post salinity exposures. The heart rate declined with increasing salinity, while Na⁺/K⁺-ATPase activity in the mantle presented a reverse trend, possibly to maintain normal osmolality. A trend of rising total haemocyte count was observed from 0 ppt and 5 ppt to 10 ppt salinities, while a sudden increase in the count was observed at 15 ppt and 20 ppt salinity groups. Furthermore, haemolymph Cl^?, Na⁺ and K⁺ concentrations increased directly with elevated salinity. An additional trial was performed to assess the growth performance of the snails under exposure to low salinities. During a 1 month trial, snails grew better at 5 ppt salinity treatment. Taken together, our results demonstrate that P. canaliculata can tolerate salt stress to some extent. The finding also obviously implies a possible invasive risk to estuaries.     

Drinking and osmoregulation in the mangrove crab Ucides cordatus following exposure to benzene

In benzene-exposed Ucides cordatus acclimated for 96 h to 9 and 34 per thousand SW, haemolymph, urine and gastric juice are isosmotic with each other, but differ significantly in osmolality from external media. In both salinities, under benzene action, urine K+ excretion and calcium absorption are increased significantly, whereas Na+ absorption and Mg2+ excretion show U/B ratios similar to control values. In 9 per thousand SW, some ionic exchanges via benzene-exposed gills are possibly hastened. Benzene exposure decreases significantly branchial chamber water osmolality, [Na+] and [K+], whereas [Ca2+] and [Mg2+] are unaffected. However, faster medium exchange presumably occurs in 34 per thousand SW, both crab groups show branchial chamber water osmotic and ionic concentrations similar to surrounding medium. Benzene exposure unaffected gastric juice composition. In both media, [Ca2+] and [Mg2] accumulate several times higher than surrounding media, and [Na+] and [K+] are significantly hypo-ionic to haemolymph. Na+ and K+ G/H ratios are lower in crabs acclimated to 34 per thousand SW than in crabs acclimated to 9 per thousand SW. Drinking rates are enhanced by benzene exposure and are higher at 34 per thousand SW than in seawater isosmotic with the haemolymph (26 per thousand SW). Benzene exposure affects significantly osmoregulatory capability, slowing haemolymph dilution after transfer to clean 9 per thousand SW. Lower haemolymph dilution rate accounts for higher osmolality, but 48 h after transfer there is no recovery like in control crabs. Haemolymph transfusion experiments suggest an interaction among effects of benzene and hormonal factors, possibly on water influx.     

Effect of sudden salinity change on Penaeus latisulcatus Kishinouye osmoregulation, ionoregulation and condition in inland saline water and potassium-fortified inland saline water

Two trials were conducted to determine the effect of sudden decrease in salinity of raw and potassium-fortified inland saline water on western king prawn Penaeus latisulcatus osmoregulation, ionoregulation and condition. Prawns were subjected to salinity decrease over 1 h from 32 to 25 ppt in the first trial and from 27 to 20 ppt in the second trial in three water types: inland saline water with potassium fortified to 100% and 80% of the marine water concentration (IS100, IS80), and raw inland saline water (ISW). In the first trial condition and ingestion rate were monitored over 19 days following salinity change. In the second trial condition, haemolymph osmo- and iono-regulation were recorded over 48 h following salinity change. In the first trial, 100% mortality was observed in ISW by day 13, with final survival 94% in IS80 and 100% in IS100. Tail muscle moisture content increased significantly (P < 0.05) over time in both trials and in all water types, suggesting loss of energy reserves. In the second trial, serum osmolality, sodium concentration and osmoregulatory capacity decreased following salinity change, stabilising by 24 h in IS100 and IS80 but continuing to decrease till 48 h in ISW, suggesting partial breakdown of osmoregulatory function in the potassium-deficient medium. Prawns were stronger regulators of divalent than monovalent cations. These trials demonstrate that potassium-deficient inland saline water requires fortification with potassium to allow prawn survival and efficient osmoregulation.     

Haemolymph osmoregulation and the fate of sodium and chloride during dehydration in terrestrial isopods

Osmoregulation of the haemolymph during dehydration was investigated in a selection of temperate oniscidean isopods. Inulin tracer studies show that the haemolymph contributes approximately 69% of water losses in Porcellio scaber, significantly more than predicted from the volume of this compartment (42% of total water). Haemolymph osmolality increases linearly as a function of haemolymph dehydration but at a significantly lower rate than predicted from the change in haemolymph fluid volume. Similar results for Oniscus asellus show that both species display efficient osmoregulation until lethal dehydration. Osmoregulation is associated with significant hyporegulation of haemolymph sodium and chloride. These findings indicate that: (1) cell water is conserved at the expense of the haemolymph; and (2) haemolymph dehydration is associated with the removal of Na(+) and Cl(-) contributing to net osmoregulation. During dehydration, accumulations of both Na(+) and Cl(-) are seen in the hindgut, with significant accumulations of electrolytes also seen in the luminal fluid of the hepatopancreas. Low fluid volumes in the foregut and hindgut suggest macromolecular association as the most plausible mechanism of ion sequestration. Evidence refutes ion excretion and haemocyte sequestration as osmoregulatory mechanisms. Sequestration of Na(+) as urate salts, as shown for Periplaneta and generally assumed for other insects, is insignificant in isopods.     

Effects of starvation on body composition and cold tolerance in the collembolan Orchesella cincta and the isopod Porcellio scaber

The effects of long-term starvation on the body composition of the isopod Porcellio scaber (Latreille) and the collembolan Orchesella cincta (L.) were studied, by determining the body composition in starved and fed animals. A period under summer conditions (19 degrees C, 75% RH and L/D 16/8 photoperiod), was followed by a period under winter conditions (5 degrees C, 75% RH and LD 6/18 photoperiod). O. cincta was held under summer conditions for 3weeks, during which its protein and lipid content decreased, while its water content increased. In P. scaber, the same occurred during the 6weeks they were kept under summer conditions. During subsequent weeks under winter conditions, changes in cold tolerance of the animals were investigated. Cold tolerance and haemolymph osmolality were measured once a week. Starved animals had lower cold tolerance than fed ones. For P. scaber a decreased haemolymph osmolality was found in starved animals compared to fed ones. This is assumed to be caused by a combination of the consumption of carbohydrates out of the haemolymph and of protein reserves and the accumulation of body water. O. cincta appeared to be capable of osmoregulation, as haemolymph osmolality did not differ between starved and fed animals, despite differences in body water content. Decreased cold tolerance in starved animals of both species may be caused by increased water content or, more probably, by the decrease in reserves needed to produce cryoprotective substances.     

饥饿及再投喂对日本囊对虾糖代谢的影响

研究了日本囊对虾在饥饿和再投喂下血糖、肝胰脏糖原和肌糖原含量的变化.结果表明：在饥饿状态下,日本囊对虾肝胰脏糖原含量和血糖浓度在饥饿开始时迅速下降,肌糖原含量在饥饿10 d时下降到最低值,在饥饿10~15 d时通过糖原异生作用又恢复至最初水平,但随着饥饿时间的延长,糖原含量持续下降.恢复投喂后,肝胰脏糖原含量和肌糖原含量均能得到较好恢复,饥饿10 d和 15 d组的血糖浓度在恢复投喂10 d后显著高于对照组,但饥饿25 d组的血糖浓度始终显著低于对照.表明饥饿时间过长,对血糖浓度的恢复有较大影响