Rhythmic swimming of the isopod Exosphaeroma obtusum (Dana)     

A. A. Fincham 《新西兰海洋与淡水研究杂志》2013,47(4):655-662

The tidal swimming rhythm of the New Zealand rocky shore isopod Exosphaeroma obtusum (Dana) is described. Peak swimming was on the ebb tide about 2.5 h after high water; the peak in the dark period was 6–8 times greater in amplitude than the daytime peak. Positive thigmotaxis was shown at all other times. The rhythm period in continuous darkness (free‐running period) was greater than tidal periodicity, and there was a semi‐lunar swimming pattern with peaks at the first and third quarters of the moon. Rheotropic experiments showed that changes in water flow did not initiate the swimming rhythm. The work was compared with the infaunal species Pseudaega punctala and the northern Eurydice pulchra. It was concluded that infaunal species rely more on endogenous control of the swimming rhythm because of their isolation, when buried, from exogenous Zeitgeber.  相似文献   

Enteroviruses in mussels and marine sediments and depuration of naturally accumulated viruses by green lipped mussels (Perna canaliculus)     

Gillian Lewis  Margaret W. Loutit  Frank J. Austin 《新西兰海洋与淡水研究杂志》2013,47(3):431-437

Surveys were carried out over 16 months to assess the distribution of enteroviruses of human origin in sediments and mussels near two sewage outfalls on the North Taranaki Coast, New Zealand. Enteroviruses were present in high numbers in both sediments and shellfish near the New Plymouth sewage outfall with maximum virus levels of 32 000 pfu 100 g^‐1 of wet mussel tissue and 59 pfu 100 g^‐1 of wet sediment material. Viruses were recovered occasionally from sediments and mussels near the Waitara Borough outfall. Coxsackievirus B4 was the predominant virus type isolated but CB5 and Poliovirus types 1, 2, and 3 were also recovered. Attempts to depurate virus‐contaminated New Plymouth mussels, by keeping them in water for 8 days with daily water replacement, did not achieve a significant reduction in virus numbers.  相似文献   

The potential food poisoning hazard of Vibrio parahaemolyticus in New Zealand Pacific oysters     

G. C. Fletcher 《新西兰海洋与淡水研究杂志》2013,47(4):495-505

The level of Vibrio parahaemolyticus was generally very low in Pacific oysters sampled from 4 New Zealand oyster farms between November 1982 and May 1983. Of the 149 samples collected, only one was found to contain greater than the 1000 organisms g^‐1regarded as the maximum allowable by international standards (International Commission on Microbiological Specifications for Foods 1982: Micro‐organisms in Foods, Vol. 2. Academic Press, New York). V. parahaemolyticus was detected in 57% of the oyster samples, but 95% of these contained less than 10 organisms g^‐1. Maximum levels appeared to coincide with high water temperatures at the farm sites. Chilling, freezing, and depuration reduced V. parahaemolyticus numbers in oysters after harvest. However, holding at ambient temperatures (19–25°C) resulted in up to a 35‐fold increase in organism numbers with a maximum after one day. The food poisoning hazard from V. parahaemolyticus in New Zealand‐grown Pacific oysters thus appears to be minimal. Recommendations are made to keep harvested shellfish cool and to chill them as soon as practical.  相似文献   

双酶分步水解金枪鱼(Eleotridae)碎肉制备高F值酶解液的工艺研究   总被引：2，自引：2，他引：0  

罗红宇  杜帅  郑斌  宋茹  杨会成 《海洋与湖沼》2013,44(4):906-912

以金枪鱼碎肉为原料, 采用双酶分步水解法制备高F值酶解液, 通过Box-Behnken试验设计, 分别确定两步酶解的最佳条件, 酶解液经活性炭静态吸附去除游离芳香族氨基酸, 对脱芳后的酶解液进行氨基酸组成分析并测定F值。结果表明, 胃蛋白酶为第一步水解用酶, 酶解的最佳工艺条件为酶用量650U/g, 料水比1∶7(g/mL), 温度35.9℃; 风味蛋白酶为第二步水解用酶, 酶解的最佳工艺条件为酶用量50700U/g, pH 6.51, 温度51℃, 最终水解度达到36.87%±0.54%; 酶解液在pH 3.0, 温度35℃条件下, 经5%(质量体积分数)的活性炭吸附时间3h后, 脱芳率达到63.18%, F值为30.33, 符合高F值肽的要求。  相似文献   

Accumulation of diarrhetic shellfish poisoning toxins in the oyster Crassostrea gigas and the mussel Choromytilus meridionalis in the southern Benguela ecosystem     

《African Journal of Marine Science》2013,35(2):273-281

Diarrhetic shellfish poisoning (DSP) poses a significant threat to the safe consumption of shellfish in the southern Benguela ecosystem. The accumulation of DSP toxins was investigated in two cultivated bivalve species, the Pacific oyster Crassostrea gigas and the mussel Choromytilus meridio-nalis, suspended from a mooring located off Lambert's Bay on the west coast of South Africa. The dinoflagellate Dinophysis acuminata, a known source of polyether toxins associated with DSP, was common through most of the study period. The toxin composition of the dinoflagellate was dominated by okadaic acid (OA) (91%), with lesser quantities of the dinophysistoxin DTX-1 (6.5%) and pecteno-toxin PTX-2 (2.4%), and traces of PTX-2sa and PTX-11. The mean cell toxin quota of D. acuminata was 7.8 pg OA cell^–1. The toxin profile in shellfish was characterised by a notably higher relative content of DTX-1. The study showed the average concentration of DSP toxins in the mussels to exceed that in the oysters by approximately 20-fold. The results indicate a need to establish species-specific sampling frequencies in shellfish safety monitoring programmes.  相似文献   

台州列岛海域贝类种类组成与分布特征   总被引：2，自引：0，他引：2  

杨俊毅  高爱根  王永泓  董永庭  王小谷 《海洋学研究》2000,18(1):37-42

根据浙江省海岛资源调查资料 ,对台州列岛海域的贝类作了统计分析。结果表明 ,该区共发现贝类 46种 ,隶属 2纲 8目 2 4科。种类组成以广温广布种为主 ,其次为亚热带种 ,暖温带种和热带种所占的比例较少。全区平均生物量为 1 8.0 6g/m2 ,平均栖息密度为 2 67.1 6个 /m2 。数量季节变化显著。这些特征与海流、沉积物等环境因子密切相关。  相似文献   

海水贝类养殖对生态系统的影响   总被引：6，自引：0，他引：6  

Zhu Mingyuan 《中国海洋大学学报(自然科学版)》2000,30(Z1):53-57

海水贝类养殖在迅速发展的同时 ,也对海洋生态系统产生了影响。这些影响包括由于贝类大量摄食而导致的浮游植物生物量 下降、种类组成改变,以及有机物质和营养盐的截留和再循环从而影响生物地球化学循环, 筏式养殖的“岛屿”效应而引起的水动力的改变。  相似文献   

红虾(Palaemon gravier)脂肪酸分析     

张强 《海洋科学进展》1998,(1)

对红虾虾头和虾肉中的脂肪进行了提取和测定。脂肪甲酯化后,采用５０ｍ×０．３５ｍｍｉ．ｄ．ＰＥＧ－２０Ｍ玻璃毛细管柱,ＦＩＤ检测器,并结合ＧＣＬＭＳ进行了脂肪酸分析。结果表明,虾头中脂肪含量达１０．８×１０－２,其不饱和脂肪酸６８．８×１０－２,ＥＰＡ＋ＤＨＡ占２４．１×１０－２;虾肉中脂肪仅为３．９×１０－２,其不饱和脂肪酸６９．８×１０－２,ＥＰＡ＋ＤＨＡ为２７．３×１０－２。  相似文献   

烟台多棘海盘车种群的个体大小分布及生殖周期     

李宝泉  周政权  李秉钧  王全超  李晓静  陈琳琳 《海洋学报(英文版)》2018,37(6):96-103

为了解烟台多棘海盘车种群个体大小分布及繁殖特征,自2010年5月至12月及2015年3月到5月,在烟台近海对该种群分别进行逐月采样调查。利用性腺指数(GI)和幽门盲囊指数(PCI)以及解剖组织学方法预测其产卵周期。结果表明：在所有的采样月份中,体长大于143mm的个体与体长小于42mm的个体在种群中均同时存在;在5-8月期间,种群结构特征以体长小于55mm的个体为主。同时该海域不同站点的采样月份中均有小个体存在,说明种群的产卵周期存在延后现象或者由于食物短缺造成了海星生长缓慢。腕长可以很好的用来衡量还行身体湿重。性腺在2010年5月-9月发育相对缓慢但在十月份迅速到达峰值20.95,之后明显下降,表明其产卵期从10月份持续至11月份。2015年3月-5月也发现了同样的现象,表明该种群自3月-5月存在另一个产卵期,且通过对卵的组织学分析也进一步证实该产卵期的存在。性腺指数和幽门盲囊指数呈负相关关系。由于食物来源短缺,烟台近海海星种群的繁殖特征极有可能受到当地近海扇贝养殖的影响。  相似文献   

氮杂螺环酸贝类毒素的研究进展     

吕金金  李宏业  刘洁生  杨维东 《海洋科学》2018,42(9):127-134

氮杂螺环酸也称原多甲藻酸,是一种具有独特螺环结构的聚醚类毒素,其对水产品的食品安全和消费者健康威胁极大,因此被双壳软体生物毒素工作组列为常见贝类毒素之一。但迄今人们对有关氮杂螺环酸的致毒机理、分子靶点以及生物毒性等,尚缺乏深入的了解。为推进对该类毒素的研究,本文就氮杂螺环酸的来源、检测方法、毒性及致毒机理以及对贝类生物的影响等进行了综述,并提出了未来需重点关注和解决的问题。  相似文献