排序方式： 共有16条查询结果，搜索用时 28 毫秒
1.
Effects of temperature and salinity on the development of embryos and larvae of the veined rapa whelk Rapana venosa （Valenciennes, 1846） 总被引：1，自引：0，他引：1
The major population of the veined rapa whelk Rapana venosa(Valenciennes, 1846), which is an important fishery resource, is facing a large decline in China. We studied the effects of incubation temperature(16–34℃ at salinity 30) and salinity(5–45 at 25℃) on the incubation period and subsequent larval development. In the temperature experiment, the shortest incubation period was 12 days at 34℃, the lower temperature limit was 16℃, the longest mean shell length(1 193±17 μm) occurred at 25℃ and the highest survival rate 72.28%±5.62% was observed at 28℃. In the salinity experiment, the shortest incubation period was 15 days at 25. The salinity tolerance range was 15–40, the longest mean shell length(855±9 μm) and the highest survival rate 72.93%±4.85% were both observed at 35. This study demonstrated that, during the egg–mass stage, temperature and salinity regimes infl uence later growth and survival of larvae. These observations deepen our understanding of the ecology and conservation of natural populations of Rapana venosa. 相似文献
2.
以小黑山岛人工鱼礁区为研究区,利用稳定同位素技术分析该海域三种习见肉食性软体动物长蛸（Octopus minor）、短蛸（Octopus fangsiao）和脉红螺（Papana venosa）的营养生态位,进而判断物种种间关系。分析结果显示食物来源范围由大到小依次为长蛸、脉红螺、短蛸,其中长蛸食物来源包含短蛸食物来源范围,但脉红螺与两种蛸类食物来源无交叉;营养级由高到低依次为长蛸、短蛸、脉红螺。长蛸与短蛸营养生态位重叠比例较高,存在明显的竞争关系,与短蛸相比,长蛸营养级更高,食物来源范围更广,在竞争中处于优势地位;脉红螺的营养生态位与两种蛸类无重叠,其营养级比两种蛸类更低,且无捕食或竞争关系。 相似文献
3.
对中国沿海脉红螺7个自然居群的线粒体DNA 16S rRNA基因片段进行了扩增和测序,分析了107个个体511bp的碱基序列,结果没有发现插入,缺失突变的核苷酸位点.检测到了28个多态性核苷酸位点,共37种单倍型,单倍型1的同源性达到58.7%.大连居群的28l(G-A)和483(T- C)位点,烟台居群的17(A-G)位点、66(T- C)和247(T-C)位点,舟山居群的128(T-C)位点,秦皇岛居群的130(T-G)和161(A-G)位点,以及丹东居群的431(T-C)位点的变异可以作为居群分子遗传标记位点.居群内,烟台和大连居群的核苷酸差异数 K 以及平均核苷酸多样性指数 Pi 最高,青岛居群最低;居群间,大连居群在居群间核苷酸差异数K、居群间平均每位点核苷酸替代数Dxy 和居群间每位点净核苷酸替代数Da三个指标上都表现出比其他居群之间较高的水平,说明大连居群具有最为丰富的遗传多样性. 相似文献
4.
采用多变量形态度量学方法,对丹东（DD）、大连（DL）、秦皇岛（QH）、烟台（YT）、青岛（QD）、连云港（LY）、日照（RZ）和舟山（ZS）脉红螺8个地理居群间的形态变异进行了比较研究,建立了居群形态聚类图和形态判别函数.结果显示：我国沿海脉红螺形态存在地理变异现象,愈向北群体间的形态变异愈明显.沿海8个居群可分为与其生态相关的两大类群,即内湾近岸类群和外海栖居类群.依据壳重/壳高为指标的差异系数判断,大连居群（DL）与相邻海域丹东（DD）和烟台（YT）居群间的差异程度达到亚种水平,其他居群间都属亚种水平下的单元.本实验所得壳的形态参数按Mayer等（1953）标准比较,秦皇岛居群（QH）仅是脉红螺的独立地方居群,尚达不到亚种水平,因此,构不成新种,传统分类上的“强棘红螺Rapana peichiliensis”不存在. 相似文献
5.
脉红螺壳口通常有3种颜色：“黑白条纹螺”、“中间螺”和“橙色螺”。本论文对3种壳口颜色的脉红螺分别进行了形态学和mt16SrRNA、COI基因片段序列比较分析。形态学分析结果表明,除厣宽／壳高、厣高／壳高、厣高／体螺层、厣高／壳口长、厣高／壳口宽、厣高／厣宽的形态学特征指数和出肉率不具有显著性差异外,其它形态特征和生物学相关变量具有显著差异,且对湿重的影响效果不同。“黑白条纹螺”壳口长和壳口宽对湿重影响最大,而“中间螺”和“橙色螺”各形态特征对湿重均无显著的直接影响。根据各形态特征均值建立的居群形态聚类图显示,“中间螺”和“橙色螺”形态差异较小,二者与“黑白条纹螺”的形态差异较大。然而基于mt16SrRNA和COI基因片段序列分析结果显示,三种壳口颜色的脉红螺无遗传分化,为同一种。 相似文献
6.
Here we report the first observations of loggerhead turtles Caretta caretta preying on a conspicuous molluscan invader, the rapa whelk Rapana venosa. An average number of 136 opercula were found in stomach contents of five turtles, the curved carapace length ranging in from 51 to 112 cm. No other alimentary items were found in the turtles analyzed. We suggest that the rapa whelk may constitute up to 100% of the diet for immature and mature loggerheads in the Río de la Plata estuary (Uruguay), highlighting the plastic nature of the foraging behavior of loggerheads. 相似文献
7.
利用实验生态学方法,通过分析摄食喜好系数、单位体质量摄食量等参数,研究脉红螺(Rapana venosa)的摄食选择性,以及饵料种类、温度和个体规格对脉红螺摄食量的影响。结果表明,脉红螺(壳长100~120mm)具有明显的摄食选择性,喜食缢蛏(Sinonovacula constrzcta)、竹节蛏(Solen gouldi)和中国蛤蜊(Mactra chinensis),但不同饵料对其摄食量的影响不显著。随着温度的升高,不同规格脉红螺的摄食量变化趋势相似,即温度低于7℃时基本不摄食,温度高于16℃时开始大量摄食,22℃左右时达到摄食高峰。不同规格的脉红螺,随壳长的增加,单位体质量摄食量逐渐减小。不同壳长的脉红螺(38~108 mm),随壳长的增加,最低摄食温度先降低(壳长50~70 mm脉红螺最低摄食温度最低)后升高。本研究为脉红螺的人工养殖提供了理论依据,同时为脉红螺的生态影响评估提供参考。 相似文献
8.
During surveillance on the toxicity of invertebrates such as bivalves inhabiting the coasts of Hiroshima Bay in 2001 and 2002, the carnivorous gastropod rapa whelk Rapana venosa collected in the estuary of Nikoh River, was found to contain toxins which showed paralytic actions in mice; the maximum toxicities (as paralytic shellfish poison, PSP) were 4.2 MU/g (May 2001) and 11.4 MU/g (April 2002). Their total toxicities were 224 and 206 MU/viscera of one specimen throughout the monitoring period. Attempts were made to identify the toxic principle in the gastropod. The viscera were extracted with 80% ethanol acidified with acetic acid, followed by defatting with dichloromethane. The aqueous layer obtained was treated with activated charcoal and then applied to a Sep-Pak C18 cartridge. The unbound toxic fraction was analyzed by high-performance liquid chromatography techniques. The gastropod toxin was rather unexpectedly identified as PSP. It was comprised of high toxic component (gonyautoxin-3; GTX3, GTX2, saxitoxin; STX) as the major components, which accounted for approximately 91 mol% of all components along with C1 and C2, which are N-sulfocarbamoyl derivatives. Judging from their toxin patterns, it is suggested that the PSP toxification mechanism of the gastropod that PSP toxins produced by phytoplankton such as Alexandrium tamarense, are transferred to and accumulated in plankton feeders such as the short-necked clam, and then transferred to this carnivorous rapa whelk R. venosa through predation. 相似文献
9.
10.
作者对不同内倾角海螺笼对脉红螺(Rapana venosa)的诱捕效果进行了实验研究。在实验室水槽中,观察了4种不同内倾角(35°、45°、55°和65°)的海螺笼对脉红螺的诱捕效果,同时还研究了光照和温度对海螺笼诱捕效果的影响,为优化海螺笼捕捞技术提供理论依据。实验结果表明:在相同的实验条件下,不同的内倾角对海螺笼诱捕效果影响十分显著(P<0.01),其中内倾角为45°的海螺笼诱捕效果最好,内倾角为35°和55°的海螺笼较好,而内倾角为65°的海螺笼诱捕效果则最差。同时发现,内倾角对脉红螺的个体大小具有选择性,随着内倾角的增大,壳高<7cm的个体占相应笼诱捕总数的百分比越来越小。光照对海螺笼的捕捞效果有十分显著的影响,而温度的影响则不明显。 相似文献