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1.
We report 11 polymorphic microsatellite loci developed from the freshwater prawn Palaemon paucidens. Their genetic characteristics were assessed in 48 individuals selected from six Korean populations. The number of alleles ranged from two to 21, and the observed and expected heterozygosities were between 0.13 and 0.83, and 0.46 and 0.95, respectively. We examined the cross-specific amplification of each locus in three species of palaemonid prawn and one species of atyid prawn.  相似文献   
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Adults of the palaemonid prawn Palaemon macrodactylus Rathbun, 1902 were reported for the first time from the southwestern Atlantic waters. Males and ovigerous females were collected in Mar del Plata harbor (38°03′ S; 57°31′ W), Argentina; larvae obtained from one of the collected females were reared in the laboratory until the juvenile stage. The geographical range of P. macrodactylus was previously restricted to the Pacific Ocean: it was originally described in Japan and has been reported as an invasive species in the western coast of USA in the 1950’s and in Australia in the 1970’s. Recently, this prawn has been also reported from European waters.  相似文献   
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The standard metabolic rate (SMR) of the caridean shrimp Palaemon peringueyi to changes in temperature (15-30 °C), salinity (0-45‰) and a combination thereof was investigated. The rate of oxygen consumption of the shrimp was determined using a YSI oxygen meter. At a constant salinity of 35‰ the respiration rate of P. peringueyi increased with an increase in temperature and ranged between 0.260 and 0.982 μl O2 mg wwt− 1 h− 1. The Q10 value over the temperature range 15-25 °C was estimated at 3.13. At a constant temperature of 15 °C the respiration rate of P. peringueyi also increased with an increase in salinity and ranged between 0.231 and 0.860 μl O2 mg wwt− 1 h− 1. For combination experiments the absence of any significant difference in the respiration rate of P. peringueyi at the four temperatures over the salinity range 15-35‰ suggests that the shrimp is well adapted to inhabiting environments characterised by variations in salinity and temperature such as those encountered within the middle and lower reaches of permanently open estuaries with substantial freshwater inflow. On the other hand, the total mortality of the shrimp recorded at salinities < 5‰ at all four temperatures suggests that the upper distribution of the shrimp may reflect physiological constraints. Similarly, the increase in the respiration rate of the shrimp at the four temperatures at salinities > 35‰ suggests that the shrimp may experience osmotic stress in freshwater deprived permanently open and intermittently open estuaries where hypersaline conditions may develop.  相似文献   
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杭州湾北部安氏白虾的繁殖生物学特征   总被引:2,自引:0,他引:2       下载免费PDF全文
王淼  周轩  徐开达 《动物学杂志》2019,54(4):509-516
采用2017年4月至2018年3月张网逐月采样数据分析杭州湾北部安氏白虾(Palaemon annandalei)的繁殖生物学特征。结果显示,安氏白虾体平均体长(32.0 ± 5.4)mm(14 ~ 51 mm,n = 3 210),抱卵群体平均体长(36.3 ± 3.4)mm(27 ~ 51 mm,n = 375)。体重分布范围为0.016 ~ 1.700 g,n = 3 210,平均体重(0.565 ± 0.282)g,抱卵群体体重分布范围为0.400 ~ 1.700 g,n = 375,平均体重(0.868 ± 0.225)g。雌、雄个体间平均体长和平均体重都具有显著性差异(P < 0.01);雌雄性比为1.27︰1,雌性个体数显著多于雄性个体数(P < 0.01)。繁殖期从4月下旬一直持续至10月下旬,6月和8月为两个繁殖旺期,抱卵率(B)和性比(S)具有显著线性相关关系(P < 0.05),关系式为B = 41.80S﹣21.06(R2 = 73.9)。绝对繁殖力为17 ~ 179粒,平均绝对繁殖力(60 ± 26)粒,平均相对繁殖力(70 ± 24)粒/g,n = 375。绝对繁殖力(FA,单位粒)与体长(L,单位mm)、体重(W,单位g)均呈二次函数显著相关(P < 0.01),关系式分别为FA = 0.29L2﹣18.52L + 342.67(R2 = 76.8)和FA = 97.32W2 ﹣100.75W + 71.66(R2 = 94.5)。卵长径分布范围为1.090 ~ 2.688 mm,平均长径(1.599 ± 0.158)mm,短径分布范围0.807 ~ 1.992 mm,平均短径(1.141 ± 0.118)mm,n = 2 787。研究表明,与20世纪80年代相比,安氏白虾个体朝小型化方向发展,繁殖周期延长,繁殖旺期由单峰型变为双峰型,这可能是生态环境持续恶化和高强度捕捞压力所致。  相似文献   
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Summary

Meiotic reinitiation has been studied in Locusta migratoria and Palaemon serratus in relation to the titre of free ecdysteroids present in the maturing oocyte. In both species meiotic reinitiation is characterized by two meiotic arrests, in prophase I and in metaphase I, and the first meiotic resumption which leads to germinal vesicle breakdown (GVBD) is correlated with increasing titres of ecdysteroids in the oocyte. Meiotic reinitiation has been successfully triggered in the oocytes of both species by incubation with physiological doses of ecdysteroids.  相似文献   
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长江口安氏白虾与日本沼虾营养成分比较   总被引:6,自引:0,他引:6  
本文对长江口安氏白虾和日本沼虾的营养成分和营养品质进行了比较.结果表明:安氏白虾的水分和粗灰分含量显著低于日本沼虾 (P<0.05),而粗脂肪和粗蛋白含量显著高于日本沼虾(P<0.05);安氏白虾和日本沼虾的氨基酸组成基本一致,均含有17种氨基酸,必需氨基酸指数(EAAI)分别为52.77和52.67,其构成比例符合联合国粮农组织/世界卫生组织(FAO/WHO)的标准;安氏白虾脂肪酸中二十碳五烯酸(EPA)与二十二碳六烯酸(DHA)的总量明显高于日本沼虾,分别为28.32%±0.49%和14.89%±0.63%;矿物元素中常量和微量元素含量均较丰富,微量元素之间的比例较合理,其中,安氏白虾的常量元素含量较高,而日本沼虾的微量元素含量较高,而日本沼虾的微量元素含量较高,从以上结果可见,安氏白虾和日本沼虾均含有较丰富的各种营养成分,但从EPA和DHA的含量来看,脂肪酸的营养价值安氏白虾高于日本沼虾;从Fe、Cu、Zn和Se的含量来看,微量元素营养价值日本沼虾高于安氏白虾.  相似文献   
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The reaction field of juvenile false percula clownfish (Amphiprion ocellaris) were studied when fed two different developmental stages (nauplii and adults) of the calanoid copepod Pseudodiaptomus annandalei. As the copepods undergo ontogenetic development, their morphologic and kinematic traits changes and may therefore influence the ability of the clownfish to identify and capture prey. The fish reacted to nauplii at shorter distances (15.2 ± 7.1 mm) compared to adult copepods (28.0 ± 9.8 mm). However, the fish reaction angle was significantly wider when offered nauplii (?25.3° to 64.4°) compared to adult copepods (?14.2° to 36.7°). This resulted in an equivalent attack rate on both prey items. Hence, even though nauplii are less apparent at greater distances, the fish counteract this partly by reacting to smaller prey items at a wider range. However, the carbon-specific ingestion rate was higher when offered adult copepods, which suggests adult copepods are a more rewarding prey.  相似文献   
10.
The feeding ecology of the caridean shrimp Palaemon peringueyi in the temporarily open/closed Kasouga Estuary, Eastern Cape, was examined during summer and winter employing stomach fullness index (SFI) analysis. Mean SFI values for male and female shrimp during summer ranged from 0.85% to 2.36% and from 0.56% and 2.61% body dry weight, respectively. During winter, SFI values for males and females were lower, and varied between 0.23% and 1.56% and 0.36% and 1.84% body dry weight, respectively. There were no significant differences in the SFI values between males and females during the two seasons. A peak in the feeding activity for both sexes was observed during the daytime during both summer and winter. For both males and females, non-linear regression analysis best explained the change in SFI over time. The gut evacuation rate constants (k) of males and females during summer were estimated at 0.43 h?1 and 0.30 h?1, respectively. These values correspond to a daily food intake equivalent to 16.2% body dwt for males and 11.1% body dwt for females. During winter, the gut evacuation rates of the shrimp were estimated at 0.35 h?1 for males and 0.28 h?1 for females. The daily ration for adult male and female shrimp during winter was estimated at 6.1% and 6.8% body dwt, respectively. The lower estimates obtained during winter appear largely to reflect the influence of the reduced water temperatures on the metabolic activities of the shrimp.  相似文献   
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