Reproductive biology of the female Japanese mantis shrimp Oratosquilla oratoria (Stomatopoda) in relation to changes in the seasonal pattern of larval occurrence in Tokyo Bay, Japan

ABSTRACT:   The reproductive traits and the monthly larval abundance of the mantis shrimp Oratosquilla oratoria were investigated in Tokyo Bay, Japan, in 2002. The goal of the study was to elucidate the cause of changes in the monthly pattern of larval abundance from the 1980s to the 1990s as these changes relate to variation in the stock size of the adult shrimp. Oogenesis was divided into 10 stages by histological observation. The developmental stage of oocytes in an individual's ovary was synchronous, suggesting that almost all the oocytes in an ovary are spawned at the same time. The size at first maturity was estimated to be 7 ≤ body length ( BL ) < 8 cm. Fecundity was expressed as a function of BL , ranging from 19 300 eggs for 8 cm BL to 92 100 eggs for 14 cm BL . Small female shrimps (<10 cm BL ) spawned around August. Most large female shrimps (≥10 cm BL ) spawned around May, and some large female shrimps also spawned until September. Although most large female shrimps spawned in spring, the larval abundance was low before July and high from August onwards. The results suggest that a substantial decrease in the stock size of large individuals causes the low larval abundance before July.     

谷氨酰胺对延边黄牛卵母细胞成熟及重组胚发育的影响

为了提高卵母细胞的成熟率及重组胚胎的发育率,在体外成熟液中添加了不同浓度的谷氨酰胺,研究谷氨酰胺对延边黄牛卵母细胞成熟的影响,并观察它对重组胚胎后续发育的影响,从中筛选出最佳的体外培养条件。结果表明,1.0 mmol/L的谷氨酰胺能够显著提高卵母细胞的成熟率,同时也能提高囊胚发育率。说明谷氨酰胺能够提高延边黄牛卵母细胞的体外成熟率,并能促进囊胚发育。     

小檗碱和川芎嗪对猪卵母细胞体外成熟中一氧化氮生成量的影响

试验以mTCM-199添加抗生素为对照组,以分别添加0.1μg/mL小檗碱(berberine,BR)和0.5μg/mL川芎嗪(ligustrazine,Lig)为试验组,比较各组卵母细胞体外成熟中一氧化氮(NO)生成量和卵母细胞的成熟效果,从而探讨中药单体成分对猪卵母细胞体外成熟过程中NO生成量的影响。结果表明:体外成熟前22 hNO生成量,对照组与Lig组差异极显著(P<0.01)、与BR组差异显著(P<0.05),Lig组与BR组差异显著(P<0.05);体外成熟后22 h NO生成量,对照、Lig及BR三组间均无显著差异(P>0.05),但Lig组的NO生成量少于BR组和对照组;体外成熟培养0～44 h不同组别NO生成量整体呈下降趋势,Lig组与BR组卵母细胞成熟率显著高于对照组(P<0.05)。结果表明卵母细胞体外成熟培养过程中,NO生成量随体外培养时间增加呈递减趋势,中药单体成分BR和Lig对卵母细胞成熟均起到一定的促进作用。低浓度NO代谢量可能对卵母细胞成熟有一定促进作用。     

胰岛素和白血病抑制因子对猪卵母细胞体外成熟和孤雌激活胚胎的影响

为探讨胰岛素(Insulin)和白血病抑制因子(Leukemia inhibit factor,LIF)对猪卵母细胞体外成熟(IVM)和猪孤雌激活胚胎(PAEs)的影响,在卵母细胞体外成熟或者胚胎培养基中添加Insulin和LIF,研究卵裂率和囊胚率的变化。结果:添加了5μg/mL Insulin后猪卵母细胞体外成熟效果显著提高,但成熟后孤雌激活发育能力与非添加组相近;而胚胎培养基中添加Insulin对孤雌胚的卵裂和囊胚的形成也没有明显促进作用;添加1 000 U/mL的LIF后,卵母细胞核成熟率没有明显提高,反而孤雌激活后囊胚率急剧下降,但对卵裂率以及囊胚总细胞数影响不大;在胚胎培养基中添加LIF后,孤雌胚的卵裂和囊胚形成并没有明显的提高。表明:Insulin对卵母细胞体外成熟有益,但是对孤雌胚胎的最佳处理程序还需要摸索;本文所采用的LIF处理对猪卵体外成熟以及孤雌胚胎体外发育没有帮助,还需要进一步研究其他浓度和处理程序对猪卵母细胞体外成熟和孤雌激活胚胎发育能力的影响。     

水牛卵泡颗粒细胞对卵母细胞体外成熟的影响

为了系统研究颗粒细胞对水牛卵母细胞体外成熟的影响,使用颗粒细胞条件液处理或单层颗粒细胞和卵母细胞共培养的方法,探讨颗粒细胞共培养对水牛卵母细胞体外成熟和早期胚胎发育的影响.结果显示,添加颗粒细胞传代接种第2天收集的20％颗粒细胞条件液到水牛卵母细胞成熟液中能显著提高水牛卵母细胞体外成熟率和囊胚发育率(P＜0.05);然...     

扁穗雀麦种子成熟过程生理响应及适宜收获期研究

为探究扁穗雀麦种子成熟过程中的生理响应,明确适宜的收获条件和时间,以扁穗雀麦"江夏"和"黔南"为试验材料,对种子成熟过程中含水量、粒重、贮藏物质、酶活性和ATP进行研究.结果表明,随着种子的成熟,含水量呈持续下降趋势,但最大失水率在品种间有较大差异."江夏"在花后第33～38天失水率最高,每天为4.94％,而"黔南"在...     

血清素在斑节对虾催熟过程中的作用

在斑节对虾 Penaeus monodon 催熟催产过程中,常用的方法是切除眼柄.此实验选用体重为149.5±25.8 g的自然海区斑节对虾,比较了注射血清素(serotonin)和切除眼柄2种处理方法对斑节对虾的催熟效果.血清素注射剂量为50 μg·g -1体重,在实验的第1、5和10天注射,共计3次.结果显示,2种方法处理后,受试亲虾性腺指数(gonad somatic index,GSI)显著高于对照组,同时注射血清素的实验组亲虾的存活率及其卵子孵化率显著高于切除眼柄的实验组.实验结果表明,血清素对斑节对虾催熟有促进作用,但发挥效应所需要的时间较长;从切除眼柄手术到第一次产卵所需时间较短,但是手术后的亲虾死亡率较高.     

Maturation of the pancreatic and intestinal digestive functions in sea bass (Dicentrarchus labrax): effect of weaning with different protein sources

The maturation of the digestive functions in sea bass (Dicentrarchus labrax) larvae was evaluated by the enzymatic profile of pancreas and intestine brush border membranes. Sea bass larvae were weaned at day 25 with three simplified diets different by their protein nature: 100% fish meal (FP), 100% casein mixture (CP) and 50% fish meal-50% casein mixture (CFP). The casein mixture contained 35% of hydrolysate. The control group was fed live preys. The specific activity of amylase decreased with age irrespectively of the diets whereas the specific activity of trypsin was enhanced. The casein mixture reduced pancreatic secretion in amylase and trypsin. The CFP group differed from the other groups fed on compound diets, exhibiting as soon as day 32 high activities of brush border enzymes, similar to controls. This sharp increase between day 25 and 32 appeared to be crucial for larval survival. The addition of a protein hydrolysate in a weaning diet seems to facilitate this maturation process.     

Life-history variation in perch (Perca fluviatilis L.) in five neighbouring Norwegian lakes

Abstract – We have studied the population dynamics and reproductive biology of perch ( Perca fluviatilis L.) from five neighbouring lakes in Norway. The lakes vary in water quality, varying from strongly acidified (pH≤5.0) to not acidified (pH≥6.0). Estimated annual survival rates did not differ among populations. There was no strong relationship between age at maturity in female perch and acidification. However, age at maturity was lower for female perch from the most acidic lake ( c . 2 years) compared with perch in the four other lakes (2.5–3.5 years). There was no relationship between acidification level and size-adjusted egg size, fecundity or reproductive investment (Gonadosomatic index – GSI). Perch in the most acidified lake showed large variation in egg size, the lowest length-specific fecundity, the highest GSI, and the lowest age at maturity. Environmental stress, such as acidification, induces a number of changes to a lake community. It is therefore difficult to predict how acidification will influence the population dynamics and reproductive biology of a perch population.