棘颊雀鲷人工繁殖与育苗的初步研究

为了解棘颊雀鲷(Premnas biaculeatus)在人工饲养条件下繁殖和仔鱼培养对光照、水温及饵料的要求,采用实验生物学的方法,在严格控制的条件下培养亲鱼、胚胎和仔鱼.结果表明,在(26±1)℃和14L:10D的光暗周期下,2 000 1x和500 1x两种光照强度对亲鱼产卵周期和卵的受精率并没有明显的影响,但是...     

现代测序技术及其在海洋生物研究中的应用

总结了目前常用的几种DNA测序技术原理、特点及其在海洋生物中的应用.展望了新技术的发展方向,以及对海洋生物研究的影响.DNA测序技术的快速发展,必将对海洋生物基础研究产生重要推动作用,为分子育种技术的发展提供基础支持,加快重要海水经济物种的新品种培育进程.     

引进印度尼西亚大珠母贝人工育苗试验

在雷州半岛海域水温24.0～30.0℃、盐度30.8～32.5、pH8.0～8.3条件下,以牟氏角毛藻,亚心形扁藻,牟氏角毛藻、亚心形扁藻和小球藻,天然混合藻等4种饵料,进行印度尼西亚产大珠母贝亲贝促熟培育试验。结果表明:不同饵料组合在亲贝促熟百分率、排精产卵率和受精率之间差异不显著(P>0.05);阴干温差流水刺激可以有效诱导亲贝排精产卵,优选幼虫和投放合适的采苗器可以提高幼虫的变态率。     

On the 2001 Splitting of the Nucleus of 51P/Harrington

The nucleus of 51P/Harrington suffered a majorsplitting event in Autumn 2001discovered by amateur José Manteca.The light curve and separation of thefragments is examined based on data fromthe observers collaborating in the Spanishlanguage ``Cometas_Obs' mailing list, includinga number of pre-announcement observations. Thereis some uncertainty in the epoch of the initiationof the split. Some evidence favours an earlierinitiation than September 2001.     

73p/Schwassmann–Wachmann 3 – One Orbit after Break-Up: Search for Fragments

We report on our search campaign for the fragments of the Jupiter family cometand target of NASA's CONTOUR mission, Comet 3P/Schwassmann–Wachmann 3, one orbit revolution after the splitting of its nucleus in 1995 (Boehnhardt et al., 1995). Fragment C was found back with coma in November 1999 at 4 AU inbound and it continued to be active during the perihelion arc until at least December 2001 when we observed it last at 3.3 AU outbound. Fragment B was observed with coma between July and September 2001 when moving outbound from 2.35 to 2.75 AU. The search for other fragments including A, D (Boehnhardt et al., 1995) and E (Kodata et al., 2000a, b; Nakamura et al., 2000) in a search area of 15 × 4 arcmin starting at fragment C along direction of the extended radius vector was not successful in July and September 2001. The limiting magnitude of this search of ∼ 25 mag in R puts an upper limit on the radius of potential fragments of about 200 m (assuming albedo 0.04). The orbit deceleration parameter and the observed coma brightness of component C suggest that this object is the primary fragment that may contain a major part of the original nucleus.     

马氏珠母贝育苗方法的多因素试验

用正交试验的方法观察影响马氏珠母贝育苗效果的七个因素：ＥＤＴＡ（Ａ）、水处理（Ｂ）、换水（Ｃ）、充气（Ｄ）、光照（Ｅ）、抗菌素（Ｆ）、倒池（Ｇ）。结果表明：影响成活率的显著因素为Ａ、Ｃ、Ｄ、Ｅ、Ｇ；影响贝苗生长的显著因素为Ｂ、Ｃ、Ｄ、Ｅ、Ｇ。加入ＥＤＴＡ、利用砂滤海水、每天换水、微弱充气、较暗的光照、使用抗菌素和定期倒池为浮游幼虫期较优的育苗方法。     

虾池微藻定向培育及其对养殖环境因子的影响

采用微藻三级扩大培养技术,将在对虾养殖池选育的波吉卵囊藻Oocysits borgei引入凡纳滨对虾Litopenaeusvannamei高位养殖池,并检测养殖环境中微藻群落结构、水质因子、对虾抗病力相关因子、对虾生长情况,研究了以微藻生态调控为主的对虾防病技术。结果表明:养殖前、中、后期,波吉卵囊藻平均生物量占浮游植物总生物量分别为98.02%、78.89%和45.12%,成为虾池中的绝对优势种;作为优势种的持续时间长达77 d。波吉卵囊藻为主的微藻群落控制的水质较稳定,实验池氨氮和亚硝酸盐氮浓度较对照池低。对虾的血细胞数、溶菌(LSZ)活力、抗菌活力、超氧化物歧化酶(SOD)和酚氧化酶(PO)均显著高于对照池(P<0.05);血清蛋白含量差异不显著(P>0.05)。实验池对虾生长速度显著高于对照池(P<0.05)。可见,通过微藻的定向培育方法来优化虾池微藻群落结构,可改善养殖环境。     

复合益生菌和底质深度对硬壳蛤育苗效果的影响

硬壳蛤(Mercenaria mercenaria)幼虫和稚贝存活率的高低是人工育苗成败的关键。本文探究了复合益生菌和底质深度对硬壳蛤幼虫与稚贝的特定生长率、存活率和变态率的影响。研究结果表明, 在投喂S2益生菌(添加丁酸梭菌代谢物的乳酸菌复合菌群)后, 小个体硬壳蛤幼虫比例减少, 幼虫的生长率和变态率显著提升; 在不同温度下, S2益生菌对来自不同地区幼虫的特定生长率有显著影响, 其中天津地区种贝所产幼虫(25℃)的特定生长率显著高于对照组幼虫(20℃), 而福建地区种贝所产幼虫(25℃)和对照组幼虫(20℃)无显著差异。此外, 3 mm深度的沙质底质显著提高了幼虫生长率、变态率和出足率。埋栖在0~3 mm深度的稚贝比例显著高于3~9 mm深度。因此,筛选促进硬壳蛤生长发育、提高成活率的复合益生菌, 确定适宜硬壳蛤生长发育的最佳底质深度, 可进一步优化其人工育苗技术, 对于大规模开展硬壳蛤人工育苗具有重要意义。     

Chlorophyll production,in response to nutrient additions,by the algae in Lake Rotorua water

Batch cultures of water and algae from Lake Rotorua were subjected to nitrogen, phosphorus, and trace element additions, singly and in combination, at monthly intervals between June 1975 and May 1976. The algal responses to the additions were assayed after 5 d incubation, by extracting the chlorophyll from the algae and estimating the concentration by fluorescence. The chlorophyll production consistently responded positively to the addition of nitrogen, while responses to the addition of phosphorus and trace elements were minor by comparison. Although the chlorophyll responses to nitrogen may not have been paralleled by actual growth, the consistent pattern of behaviour by algae in the batch cultures was interpreted as evidence of persistent shortage of nitrogen in the Lake Rotorua environment.     

Pelagic microplastics around an archipelago of the Equatorial Atlantic

Plastic marine debris is presently widely recognised as an important environmental pollutant. Such debris is reported in every habitat of the oceans, from urban tourist beaches to remote islands and from the ocean surface to submarine canyons, and is found buried and deposited on sandy and cobble beaches. Plastic marine debris varies from micrometres to several metres in length and is potentially ingested by animals of every level of the marine food web. Here, we show that synthetic polymers are present in subsurface plankton samples around Saint Peter and Saint Paul Archipelago in the Equatorial Atlantic Ocean. To explain the distribution of microplastics around the Archipelago, we proposed a generalised linear model (GLM) that suggests the existence of an outward gradient of mean plastic-particle densities. Plastic items can be autochthonous or transported over large oceanic distances. One probable source is the small but persistent fishing fleet using the area.