饲料蛋白水平对罗氏沼虾(Macrobrachium rosenbergii)生长和消化酶活性的影响

探讨了饲料中不同蛋白水平（ω（蛋白）分别为20.2%,29.6%,40.8和51.2%）对罗氏沼虾（Macrobrachium rosenbergii）生长和消化酶活性的影响。结果表明,在本实验范围内,饲料中不同蛋白水平对罗氏沼虾的特殊生长率（YSGR）影响不显著（P＞0.05）,对淀粉酶的比活性也无显著影响（P＝0.108）,但显著影响类县蛋白酶（P＝0.017)和胃蛋白酶的比活性（P＝0.002）,在同一蛋白水平下,淀粉酶比活性最高,其次为类县蛋白酶和胃蛋白酶,3种消化酶的比活性在ω（蛋白）＝51.2％组最高,随着饲料中蛋白水平的上升,3种消化酶的比活性也呈逐渐上升的趋势,而淀粉酶与类胰蛋白酶比活性的比值逐渐下降,表明罗氏沼虾消化酶活性对饲料中蛋白含量有适应性反应。     

不同体重罗氏沼虾亲虾的代谢

在实验室中测定６个体重组（１２．２４,１７．９３,２２．０６,２７．２７,３２．５２和３９．７３ｇ）的罗氏沼虾亲虾的基础代谢,以探讨体重变化影响代谢的规律。结果表明,耗氧率和氨氮排泄率都随体重的增大而减少,其关系可表示为：ＲＯ＝１．６３９３Ｗ＾０．４６３８和ＲＮ＝０．７９１５Ｗ＾－１．２７８０．不同体重亲虾的能耗率和能源物质的供能比有显著性的差异．     

罗氏沼虾幼体复眼发育扫描电镜观察

用扫描电镜研究了罗氏沼虾（Macrobrachium rosenbergii） 状幼体复眼形态发育,结果显示出从 Ⅰ到Ⅸ复眼的形态发生了变化。组成复眼的小眼由圆形、椭圆形的泡状突起发育成分布于不同部位的五边形、扁平六边形和四边形。小眼的平均面积由 Ⅰ期的94．4μm^2增长为 Ⅸ期的527．1μm^2。小眼的数量也随复眼的发育而逐步增多，由 Ⅰ期的122个左右增加到 Ⅸ的289个左右，复眼的表面积从 Ⅰ的0．01mm^2到 Ⅸ的0．15mm^2。观察结果说明： 状幼体复眼的面积的增大主要是由于小眼面积的增大而引起的。最早出现四边形小眼的部位是在复眼近体轴侧，到 Ⅸ远体轴侧仍然还有六边形小眼，说明小眼的发育顺序是从近体轴侧到远体轴侧。     

粗糙沼虾鳃的组织学研究

应用切片技术研究了粗糙沼虾鳃的组织学。结果表明：粗糙沼虾具有7对鳃，每个鳃均由鳃轴和数条鳃叶构成。鳃轴主要由结缔组织构成，背、腹面分别具有一条入鳃血管和出鳃血管。鳃轴内含有鳃腺、肾原细胞和营养细胞。鳃叶是鳃的基本呼吸单位，平行着生在鳃轴的两侧。鳃叶壁由单层扁平上皮及几丁质层构成；鳃叶边缘具有入鳃边缘血管和出鳃边缘血管。     

罗氏沼虾的染色体研究

从罗氏沼虾处于囊胚期和原肠期的胚胎细胞中提取中期染色体进行细胞遗传学研究。染色体制片分析表明，罗氏沼虾二倍体染色体数目2N=118，但是也有一些细胞具有100～109条染色体。以外，还有一些细胞具有与单倍体染色体数相近的染色体数。     

日本沼虾体内RNA/DNA比值与其生长关系的研究

测定了白洋淀野生日本沼虾不同生长阶段的体长、体重以及肝胰腺和肌肉中RNA/DNA比值,通过回归分析拟合得到体重与体长、RNA/DNA比值与体长关系的数学方程.结果显示,体重与体长的关系可用幂方程(W=0.004 5L3.985 9,R2=0.98,P<0.01)来表示,而肝胰腺和肌肉中RNA/DNA比值与体长的关系则为指数式方程(RL=-0.225 3e0.74L,R2=0.968,P<0.01;RM=0.051 2e1.195 1L,R2=0.974,P<0.01),与体重关系为RL=1.592 4e0.821 5w(R2=0.969 9,P<0.01)和RM=1.198 9e1.330 5w(R2=0.981 3,P<0.01).RNA/DNA比值能较好指示日本沼虾的生长状况,为日本沼虾的生物学研究提供了重要的参考指标.     

日本沼虾Macrobrachium nipponense（de Haan）卵子附着机制研究I．卵膜及卵子附着的扫描电镜观察

用扫描电镜技术观察了日本沼虾（Ｍａｃｒｏｂｒａｃｈｉｕｍｎｉｐｐｏｎｅｎｓｅ）成熟卵、人工授精卵及自然受精产出附着于腹肢上的卵。成熟卵只有初级卵膜，表面较光滑，上密布微孔，密度约１～２个／μｍ２；人工授精卵表面首先突起大小不同的颗粒，随后颗粒破裂并消失，同自然受精卵一样，卵表略光滑，呈波浪状起伏，微孔密度与未受精前大致相同；自然产出的受精卵，表面覆盖一层由雌体腹肢分泌的次级卵膜。次级卵膜具有保护、选择性渗透及隔离邻近受精卵的作用。腹肢不断摆动，受精卵在腹肢间滚动并形成卵与卵之间以及卵与刚毛之间两种“卵柄”，一种称为卵索（ｆｕｎｉｃｕｌｕｓ），不与刚毛相连。ｆｕｎｉｃｕｌｕｓ扁带状，与卵接触处较宽，约１４０～１５０μｍ，中间宽约３０～４０μｍ；另一种称为卵柄（ｅｇｇｓｔａｌｋ），由１～２根载卵刚毛（ｏｏｓｅ－ｔａｅ）插入次级卵膜形成，与卵接触处次级卵膜突起呈锥状，基部宽约１４０～１５０μｍ。非载卵刚毛起辅助抱卵作用。     

硫化氢对罗氏沼虾4种组织中POD、PPO酶活力的影响

将罗氏沼虾暴露在0、0.05、0.1、0.15、0.2 mg/L硫化氢中12 h后显示,随着硫化氢浓度的增加,其肝脏、心脏、鳃、复眼4种组织中POD和PPO的酶活力呈先增加后减少的变化趋势.结果表明:硫化氢对罗氏沼虾4种组织中POD和PPO酶活力的影响与浓度有关,其中对肝脏和鳃两种组织中POD、PPO酶活力的影响明显大于其他组织,这两种免疫相关酶的酶活力变化可以灵敏地反映虾类养殖水体中硫化氢的胁迫程度和毒性.     

Epibionts and parasites of Macrobrachium rosenbergii and Metapenaeus dobsoni from Gosthani estuary

Juveniles of two species of commercially important prawns, Metapenaeus dobsoni (Miers) and Macrobrachium rosenbergii (De Man) collected from Gosthani estuary, Bheemunipatnam near Visakhapatnam, India during the period August 1995 to August 1996 were subjected to a detailed study with a view to identifying the various species of epibionts and parasites and to monitor the seasonal changes in the occurrence and abundance of common species of ciliates and larval helminths. A wide range of protozoan and metazoan parasite species was encountered in the prawns. The protozoans were represented by epicommensal ciliates belonging to the genera Zoothamnium, Epistylis, Acineta, Vorticella, an unidentified apostome ciliate and two species of gregarines. The metazoan parasites included metacercariae of families Opecoelidae and Microphallidae, a larval cestode, a larval nematode and two species of bopyrid isopods. Altogether eight species were found infecting M. rosenbergii and 11 species infected M. dobsoni. A majority of the parasite species infected both the hosts. The peritrichous and apostome ciliates constituted the dominant members of the parasite fauna, occurring on both species of prawns as epibionts with high prevalence and density. All the other infections were rarely encountered. Infections with gregarines were restricted to M. dobsoni while those of microphallid metacercariae were found only in M. rosenbergii. Zoothamnium infections were more common on M. rosenbergii than on M. dobsoni. Apparent differences in the parasite fauna, attributed to differences in the behaviour of the two species, were noted. Seasonally Zoothamnium infections were at their peak during monsoon and post-monsoon months and these infections appear to be governed directly by salinity of the habitat and indirectly by the rainfall. Apostome ciliate infections were at their peak during the months November and February. Opecoelid metacercarial infections were confined to the period August to February, with peak during summer months.