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1.
利用水平淀粉凝胶电泳方法对方蟹科肉球近方蟹,绒螯近方蟹及平背蜞进行遗传分析,计检测了11 种同工酶,16 个位点。结果表明,三种蟹类的多态座位比例分别为:0.188,0.063,0.063;平均杂合度分别为:0.009,0.001,0.044。肉球近方蟹、绒螯近方蟹间的根井遗传距离为1.080。平背蜞与肉球近方蟹、绒螯近方蟹的根井遗传距离分别为1.717 和1.707  相似文献   

2.
Nematode assemblages were investigated (in terms of size spectra, sex ratio, Shannon diversity, trophic structure and diversity, rarefaction statistics, maturity index, taxonomic diversity and taxonomic distinctness) at bathyal and hadal depths (from 1050 to 7800 m) in the deepest trench of the South Pacific Ocean: the Trench of Atacama. This area, characterised by very high concentrations of nutritionally-rich organic matter also at 7800-m depth, displayed characteristics typical of eutrophic systems and revealed high nematode densities (>6000 ind. 10 cm−2). Nematode assemblages from the Atacama Trench displayed a different composition than at bathyal depths. At bathyal depths 95 genera and 119 species were found (Comesomatidae, Cyatholaimidae, Microlaimidae, Desmodoridae and Xyalidae being dominant), whereas in the Atacama Trench only 29 genera and 37 species were encountered (dominated by Monhysteridae, Chromadoridae, Microlaimidae, Oxystominidae and Xyalidae). The genus Monhystera (24.4%) strongly dominated at hadal depths and Neochromadora, and Trileptium were observed only in the Atacama Trench, but not at bathyal depths. A reduction of the mean nematode size (by ca. 67%) was observed between bathyal and hadal depths. Since food availability was not a limiting factor in the Atacama Trench sediments, other causes are likely to be responsible for the reduction of nematode species richness and body size. The presence of a restricted number of families and genera in the Atacama Trench might indicate that hadal sediments limited nematode colonisation. Most of the genera reaching very high densities in Trench sediments (e.g., Monhystera) are opportunistic and were responsible for the significant decrease of the maturity index. The dominance of opportunists, which are known to be characterised by small sizes, might have contributed to the reduced nematode size at hadal depths. Shannon diversity and species richness decreased in hadal water depth and this pattern was more evident at genus than at species level. Epistrate feeders dominated and increased their relevance, determining a reduction of the index of trophic diversity at hadal depths. According to trophic diversity, taxonomic diversity and distinctness also decreased with depth. All diversity indices from the Atacama Slope and Trench were lower than in other equally deep areas world wide (e.g. Puerto Rico Trench). We suggest that such reduction was related to the high nutrient loading observed in this system (up to two orders of magnitude higher than in typical oligotrophic deep-sea sediments).  相似文献   

3.
Meiofaunal assemblages were investigated (in terms of abundance, biomass, individual size and community structure) at bathyal and hadal depths (from 1050 to 7800 m) in the Atacama Trench in the upwelling sector of the eastern South Pacific Ocean, in relation to the distribution and availability of potential food sources (phytopigments, biochemical compounds and bacterial biomass) in this highly productive region. Meiofaunal density and biomass in the Atacama Trench were one to two orders of magnitude higher than values reported in other “oligotrophic” hadal systems. The Atacama Trench presented very high concentrations of nutritionally rich organic matter at 7800-m depth and displayed characteristics typical of eutrophic systems. Surprisingly, despite a decrease in chlorophyll-a and organic matter concentrations of about 50% from bathyal to hadal depths, meiofaunal abundance in hadal sediments was 10-fold higher than at bathyal depths. As indicated by the higher protein to carbohydrate ratio observed in trench sediments, the extraordinarily high meiofaunal density reported in the Atacama Trench was more dependent upon organic matter quality than on its quantity. The trophic richness of the system was reflected by a shift of the size structure of the benthic organisms. In contrast with typical trends of deep-sea systems, the ratio of bacterial to meiofaunal biomass decreased with increasing depth and, in the Atacama Trench, meiofaunal biomass largely dominated total benthic biomass. Nematodes at 7800-m depth accounted for more than 80% of total density and about 50% of total meiofaunal biomass. In hadal sediments a clear meiofaunal dwarfism was observed: the individual body size of nematodes and other taxa was reduced by 30–40% compared to individuals collected at bathyal depths. The peculiarity of this trophic-rich system allows rejection of previous hypotheses, which explained deep-sea dwarfism by the extremely oligotrophic conditions typical of deep-sea regions.  相似文献   

4.
长毛明对虾野生群体的杂合性研究   总被引:1,自引:0,他引:1  
应用聚丙烯酰胺凝胶电泳技术,研究了长毛明对虾(Fenneropenaeus penicillatus)9个野生群体杂合子缺乏及过量情况;测定了8个酶系统,共检测到15个酶位点和32个等位基因.有7个多态位点,它们是Me-1、Me-2、Mdh-2、Aat-1、Sod-2、Est-1、Amy-1位点,在这些位点有2~5个等位基因.结果表明,在长毛明对虾9个群体的全部多态位点中,共有6个位点符合哈温平衡(P〉0.05),30个位点偏离哈温平衡(p〈0.05);除宁德群体外,其他8个群体中共有13个多态位点表现为杂合子缺失,结合每个群体中各个多态位点的期望杂合度与观察杂合度,认为导致杂合子缺乏的主要原因可能是种群内交、自然选择、Wahland效应、哑等位基因等.另外,在本研究中共有23个位点表现为杂合子过剩(F〈0),且在长毛明对虾9个群体中均有出现,从而认为长毛明对虾的种质资源较好.  相似文献   

5.
长毛对虾、短沟对虾和日本对虾的染色体研究   总被引:4,自引:1,他引:4  
目前,利用高新技术,如实行生殖和遗传操作进行对虾品种改良的设想正在中国、美国、澳大利亚和日本等国加紧实施,但对虾遗传和生殖学研究尚欠深入,限制了这项研究的进展。其中对虾染色体知识的贫乏和研究技术的短缺就是突出的一例。  相似文献   

6.
The Atacama trench, the deepest ecosystem of the southern Pacific Ocean (ca. 8000 m depth) was investigated during the Atacama Trench International Expedition. Sediments, collected at three bathyal stations (1040–1355 m depth) and at a hadal site (7800 m) were analyzed for organic matter quantity and biochemical composition (in terms of phytopigments, proteins, carbohydrates and lipids), bacterial abundance, biomass and carbon production and extracellular enzymatic activities. Functional chlorophyll-a (18.0±0.10 mg m−2), phytodetritus (322.2 mg m−2) and labile organic carbon (16.9±4.3 g C m−2) deposited on surface sediments at hadal depth (7800 m) reached concentrations similar to those encountered in highly productive shallow coastal areas. High values of bacterial C production and aminopeptidase activity were also measured (at in situ temperature and 1 atm). The chemical analyses of the Atacama hadal sediments indicate that this trench behaves as a deep oceanic trap for organic material. We hypothesize that, despite the extreme physical conditions, benthic microbial processes might be accelerated as a result of the organic enrichment.  相似文献   

7.
长毛对虾卵子发生的研究Ⅱ.卵黄发生   总被引:19,自引:1,他引:19  
洪水根 《海洋与湖沼》1992,23(3):280-284
自1985—1988年,每年4,5月间取厦门海区捕捞的长毛对虾雌虾卵巢为材料,应用光镜和电镜技术并结合细胞化学方法,研究长毛对虾的卵黄发生。结果表明,卵黄粒在卵黄发生的卵母细胞核外围的卵质中最早出现;卵黄粒的形成有多种途径,最先参与卵黄粒形成的细胞器是线粒体;随后高尔基液泡、内质网膜囊、溶酶体及核糖体等细胞组分参与了卵黄粒的形成。还讨论了滤泡细胞与卵黄蛋白来源之间的关系。  相似文献   

8.
本文报道应用有机碘防治养殖对虾疾病的试验。结果表明,15.0mg/dm3浓度的药液消毒可杀死水体中大量细菌,0.3mg/dm3浓度的药液对对虾的蜕壳有促进作用,按一定比例加工成配合饵料投喂对虾,在虾病狂发期可延长养殖时间。文章还对有机碘防治对虾疾病的有关机理进行了初步探讨。  相似文献   

9.
长毛对虾酸性磷酸酶功能基团的研究(Ⅱ)   总被引:1,自引:0,他引:1  
用化学修饰剂pCMB、NBS、K试剂修饰长毛对虾Penaeuspenicilla-tusAlcock酸性磷酸酶(ACPase,EC3.1.3.2),在修饰剂作用下,酶活力明显下降,健康虾酶对修饰剂的敏感性(NBS除外)大都稍大于病虾酶。修饰酶的紫外280um吸收光谱以及荧光340um发射光谱的变化,表明酶活力下降的同时酶构象也产生相应的变化。结果表明,酶分子的半胱氨酸残基、色氨酸残基以及门冬氨酸、谷氨酸β或γ验基与酶活力有关,是酶的催化功能基团。  相似文献   

10.
中国海域已报道的约90种对虾中,半数具有经济价值。其中中国对虾、墨吉对虾和长毛对虾无论在捕捞还是在养殖业上都具有十分重要的地位。由于3种虾的形态非常相近,特别是在早期生活史阶段,它们的幼体和仔虾很难区分,因而给对虾种群补充、预报和其它有关研究造成困难。尤其在热带海域,对虾生殖季节重叠,幼体和仔虾的鉴别更加重要,各期仔虾的数量统计需以严格的形态鉴别作为依据。作者对三种对虾的幼体的形态,区别已有专文报道(Liu and Liu,1994)。本文深入细致地研究了中国对虾、墨吉对虾和长毛对虾仔虾的发育形态学,并进行了比较,使3种对虾的仔虾得以区别,并为今后的对虾生态学研究及资源管理奠定基础,提供依据。  相似文献   

11.
本文试验了8种药物对长毛对虾受精卵孵化率的影响,结果表明,低剂量药物对受精卵的孵化有显著的促进作用,而高剂量药物则有显著的抑制作用。  相似文献   

12.
福建漳浦前亭综合养殖系统1^#池的主养种为菲律宾蛤仔(Ruditapes philippinarum)和池蚶(Tegillarca granosa),搭养种为日本对虾(Penaeus japonicus)和长毛对虾(Penaeus penicillatus).2^#池的主养种为菲律宾蛤仔,搭养种为日本对虾。1999年8月至2000年7月的周年跟踪调查结果表明:这两口综合养殖池9个水质理化因子(水温、透明度、盐度、氨氮、亚硝酸氮、硝酸氨、活性磷酸盐、pH值、化学需氧量)和2个沉积物指标(有机质、硫化物)的测值大多数符合养殖标准。1^#池COD、有机质和硫化场的测值大多数比2^#池的低得多,这表明不同综合养殖系统的生态环境条件不同,养殖效益也不同。  相似文献   

13.
6个虾种基因组DNA多态性分析   总被引:2,自引:0,他引:2  
许玉德  孙晟 《海洋科学》2001,25(1):9-11
采用RAPD方法检测了罗氏沼虾(Macrobrachium rosenbergii)、绿须虾(Aristeus virilis)、长毛对虾(Penaeus penicillatus)、日本对虾(P.japonicus)、斑节对虾(P.monodon)和周氏新对虾(Metapenaeus joyneri)等6个虾种的基因组DNA的多态性。用20个随机引物扩增得到492个DNA片段,根据这些片段的共享度计算出遗传距离并构建系统树。所得结果从DNA水平上反映出虾类在科属种不同分类阶元亲缘关系的远近,并为虾类现行的分类系统提供了分子生物学依据。  相似文献   

14.
The burrowing behaviour of Ovalipes catharus (White, 1843) is described and compared with that of some other burrowing crabs. O. catharus is a fast, back burrowing crab which makes temporary burrows in soft sand. The average time from initiation of burrowing to complete submergence was 6.5 s, there was no difference between males and females but burrowing time increased significantly with crab size. Similar morphological adaptations are required for burrowing and swimming: streamlined body shape, smooth lightly constructed exoskeleton, and flattened legs. O. catharus has a reversed respiratory current like O. guadulpensis but it differs in its burrowing behaviour. Compared to some other crabs, burrowing in O. catharus is rapid.  相似文献   

15.
The larval shells of Paphies ventricosa, reared to settlement in the hatchery, are similar in longitudinal profile to shells of some other mactracean larvae; the umbo‐stage larval shells are nearly round with the anterior margin less broadly curved than the posterior margin, the anterior end is longer than the posterior end, and the umbo is broadly rounded. Straight‐hinge larvae had total lengths up to 149 μm, and total heights up to 126 μm, and umbo larvae had total lengths up to 320 μm, and total heights up to 282 μm. The larvae settled in about 22 days at a size of about 270 μm. The larval hinge structure bears some similarities to those of other mactracean larvae.  相似文献   

16.
中国海欧努菲虫复合种(Polychaeta,Onuphidae)的分类修订   总被引:1,自引:1,他引:0  
通过对中国科学院海洋生物标本馆历年收藏的欧努菲虫属Onuphis标本的系统研究,发现我国被广泛报道的多毛类物种欧努菲虫O. eremita AudouinMilne Edwards, 1833为错误记录,该种在在中国海并无分布,绝大部分标本应鉴定为入江欧努菲虫O. iriei MaekawaHayashi, 1999,少数为中华欧努菲虫O.chinensisUschakovWu,1962、福建欧努菲虫O.fujianensisUschakovWu,1962、乌氏欧努菲虫O. uschakovi WuXu, 2017及色斑欧努菲虫O. variolata Shen, 1987。本文回顾了O. eremita和O. iriei的分类研究历史,对我国入江欧努菲虫的头部、疣足、刚毛等形态结构及地理分布进行全面研究,同时对上述欧努菲虫复合种做了形态比较,澄清了欧努菲虫长达30年的分类学误识。  相似文献   

17.
The oxygen consumption rates and activities of key metabolic enzymes were measured and analyzed as a function of habitat depth for several species of benthic octopod (Cephalopoda: Octopoda) including a recently described hydrothermal vent endemic species. Oxygen consumption rates and citrate synthase activity, an indicator of aerobic metabolic potential, did not vary significantly with increasing habitat depth. Anaerobic metabolic potential, as evidenced by octopine dehydrogenase activity, declined significantly with increasing habitat depth. It is suggested that burst swimming abilities, and hence glycolytic potential, are not strongly selected for in the deep-sea, where visual predator-prey interactions are reduced because of light-limitation. Oxygen consumption rates for Octopus californicus and O. bimaculoides were analyzed as a function of oxygen partial pressure as well. O. californicus, which lives in the hypoxic Santa Barbara basin at 500 m depth, was able to regulate its oxygen consumption to the limit of detectable oxygen partial pressures. O. bimaculoides, an intertidal species, had a minimum critical oxygen partial pressure of 16 mmHg. It is also shown that oxygen consumption rates and oxygen consumption regulation are strongly affected by individual experiment duration (either handling stress or food deprivation). O. californicus appears to be much more strongly affected by experiment duration than is O. bimaculoides.  相似文献   

18.
不同虾种间肌肉组织蛋白质的比较   总被引:2,自引:0,他引:2  
许玉德  孙晟  朱云 《台湾海峡》2001,20(2):177-181
采用薄层等电聚焦凝胶电泳方法对罗氏沼虾(Macrobrachium rosenbergii)、绿须虾(Aristeus virilis)、长毛对虾(Penaeus penicillatus)、日本对(P.japonicus)、斑节对虾(P.monodon)和周氏新对虾(Metapenaeus joyneri)的肌肉组织蛋白质进行分离,检测各蛋白质组份及其等电点。根据蛋白质区带的共享度计算共相互间的遗传距离指数,然后用聚类方法处理数据,构建系统树,分析其间的差异程度,最后确定6种虾的亲缘关系。结果表明,每种虾可获得6-11条 蛋白质区带,等电点范围在4-6.95之间。虾类肌肉组织蛋白质组份及其电泳行为,可为虾类在分类学上的定位提供生化依据。  相似文献   

19.
Despite the wide distribution of zoanthids, little is known about their pattern of reproduction. Here we investigate the reproductive biology of two Mediterranean species, the common Parazoanthus axinellae (Schmidt) and the rare Savalia savaglia (Bertoloni). For both species, samples were collected during an annual cycle, from January to December 2005, in the Western Mediterranean (Ligurian Sea, Italy). Both species are gonochoric. In P. axinellae the sex‐ratio (n colonies = 30) showed a slight predominance of male colonies (M/F = 1.35), whereas in the population of S. savaglia (n colonies = 15) a predominance of females was found (M/F = 0.3). In P. axinellae the first gametocytes were visible in March, whereas in S. savaglia they became visible in May. Both species reproduce at the end of autumn when seawater temperature begins to decrease. Parazoanthus axinellae (10 m depth) spawns eggs and sperms in November, whereas S. savaglia (67 m depth) spawns in December. In P. axinellae sexes were segregated on a rocky wall, with males occurring deeper, whereas male and female colonies of S. savaglia were irregularly dispersed in the population. The maximum number of oocytes differed between the species, being higher in P. axinellae than in S. savaglia.  相似文献   

20.
Diel vertical migration (DVM) of medusae was investigated at a fixed station in the oligotrophic Southern Adriatic Sea at several depths during summer (July) 2003. We hypothesized that medusan DVM is considerably influenced by environmental variables such as hydrographic features, light intensities, and potential prey densities. We used short-term repetitive sampling as an approach to detail these relationships. Of the 26 species collected, the highest abundance was in the layer between the thermocline (15 m) and 100 m depth, where Rhopalonema velatum predominated, reaching the maximum count of 93 individuals per 10 m3. Seven species were observed over a wide depth range: Solmissus albescens (15–1200 m), R. velatum (0–800 m), Persa incolorata (50–1200 m), Octophialucium funerarium (200–1200 m), Arctapodema australis (200–1200 m), Amphinema rubra (100–800 m), and Rhabdoon singulare (15–600). According to the medusan weighted mean depth (WMD) calculations, the longest DVMs were noted for the deep-sea species S. albescens , O. funerarium , and A. australis . The shallowest species, Aglaura hemistoma , was primarily non-migratory. Certain medusan assemblages were associated consistently with a particular depth layer characterized by a particular light intensity. The interplay of environmental factors and trophic relationships explains some of the features of medusan migratory patterns. These findings thus contribute to understanding the variables that determine patterns of medusan vertical migratory behavior.  相似文献   

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