Oceanological conditions and reproduction of the spotted seal (<Emphasis Type="Italic">Phoca larga</Emphasis>) in Peter the Great Bay of the Sea of Japan

The long-term studying of the reproduction of the spotted seal Phoca larga and the analysis of the oceanological conditions in Peter the Great Bay of the Sea of Japan have shown that the ice situation is not right for the successful parturition and breeding of pups due to the impossibility of synchronization of the reproduction processes with the dynamics and properties of the ice substratum. A major factor promoting the spotted seal’s coastal reproduction in this area is the existence of an archipelago of small islands with a specific geomorphological structure. Being the historical norm, the coastal reproduction has a number of advantages in comparison with ice reproduction and, as a whole, allows the existence in Peter the Great Bay of local groupings of the spotted seal with extremely small numbers of members.     

Vegetative reproduction by multicellular propagules in Rhodophyta: an overview

This paper deals with vegetative reproduction by multicellular propagules in Rhodophyta. An extensive examination of the relevant literature shows that this phenomenon in Rhodophyta is not well known. A propagule is here defined as a vegetative multicellular structure which spontaneously detaches from the parent thallus and gives rise to a new individual. The origin and morphological features of multicellular propagules are examined in the various known propagule‐forming species. The importance of multicellular propagules as both overwintering and resting organs and as a taxonomic feature is also shown. Their role in increasing local populations and/or for long‐distance dispersal is discussed. The relative abundance of vegetative reproduction by multicellular propagules versus sexual reproduction, as well as the advantages of this additional mode of reproduction, are shown and discussed. The production of multicellular propagules may contribute to the capacity of species to increase populations, to weather unpredictable environmental changes, to survive in conditions that would be lethal for entire thalli, and to reach new habitats. As resting organs, they may also be responsible for long‐distance dispersal and may account for the introduction of some alien species. Accordingly, propagule‐forming species are probably more competitive than taxa that do not produce such propagules. These considerations should be taken into account in future studies of the biology, ecology and demography of Rhodophyta.     

The role of gametes of the macroalgae <Emphasis Type="Italic">Ascophyllum nodosum</Emphasis> (L.) Le Jolis and <Emphasis Type="Italic">Fucus vesiculosus</Emphasis> L. (Fucales,Phaeophyceae) in summer nanoplankton of the White Sea coastal waters

Studies of macrophytes in the coastal zone of the Artic Seas, including the White Sea, have shown the essential role of these algae in the activity of the coastal half-latitude ecosystems. In summer, during the macrophyte reproduction period, a great number of reproduction products are released into the water. For a short time, this considerably affects the ratio of the nanoplankton in the populations that inhibit the vast and shallow coastal areas. At different coastal sites in Chernorechenskaya Inlet, Kadalaksha Bay, during the period of intensive reproduction of Ascophyllum nodosum and Fucus vesiculosus, 42 plankton samples were collected in 2005. During this period the concentration of antherozoids in the water reached 55000 cells/ml (216 mg C/m³). The number of eggs was within the range of 0.05–0.7 cells/ml. The proportion of antherozoids in the total biomass of nanoplankton varied at different coastal sites from 0.37 to 99%, with a mean of 46% for the reproduction period of A. nodosum, and only 7% for the reproduction period of F. vesiculosus. As was shown by counts of F. vesiculosus female gametes in sedimentation traps, 1 m² of the macrophyte bed (assuming 100% coverage) produces 18000–108000 eggs per day (0.33–2 mg C). The calculated flux of the reproductive material from the brown algae beds to the coastal water shows good agreement with the sample counts.     

广西涠洲岛黄廯蜂巢珊瑚、肉质扁脑珊瑚的胚胎和幼虫的早期发育

研究造礁石珊瑚的有性繁殖来探索珊瑚礁的生态修复是近年来的热点。本文于2018年5月采集广西涠洲岛自然海域中的黄廯蜂巢珊瑚(Favia favus)和肉质扁脑珊瑚(Platygyra carnosus)至室内养殖,收集受精卵,观察和记录其胚胎和幼虫的早期发育过程。结果显示,黄廯蜂巢珊瑚和肉质扁脑珊瑚都是雌雄同体,体外受精,在月圆后5~8 d产卵;发育过程都经历卵裂期、囊胚期、原肠胚期以及浮浪幼虫期;两者的卵母细胞都不含虫黄藻。本研究记录了涠洲岛造礁石珊瑚的有性繁殖行为,为进一步利用有性繁殖来进行珊瑚礁的生态修复提供了理论基础。     

膨胀蔷薇珊瑚与壮实鹿角珊瑚的胚胎和幼虫发育

造礁石珊瑚的有性繁殖是修复珊瑚礁生态系统的有效途径之一.文章为国内首次报道造礁石珊瑚有性繁殖和幼体发育过程,为利用有性繁殖技术恢复珊瑚礁生态系统提供了发育生物学上的理论基础.海南省三亚市鹿回头海域的大部分珊瑚在2009年3月底至4月中发生有性繁殖行为.2009年4月11日晚采集膨胀蔷薇珊瑚Montipora turgescens和壮实鹿角珊瑚Acropora robusta自然排放的受精卵,研究其胚胎及幼虫发育的过程.通过连续观察和显微拍摄记录了2种珊瑚的受精卵发育过程,结果显示,受精卵经过分裂变为桑葚胚;桑葚胚经过进一步发育变形为虾片状,进而发育成盘状幼体;盘状幼体由四周向内弯曲形成碗状的结构,进而出现原肠胚及纤毛,发育成为椭圆型或圆形的浮浪幼虫;浮浪幼虫发生附着变态,长出触手,发育成珊瑚幼体.通过观察还发现,膨胀蔷薇珊瑚的卵母细胞中本身就含有黄褐色虫黄藻,壮实鹿角珊瑚的卵母细胞中没有虫黄藻,其共生的虫黄藻足在发育过程中从周围环境获得的.     

雨生红球藻的细胞周期初探

于１９９７年在青岛利用显微镜连续观察技术研究了雨生红球藻的细胞繁殖方式和动力学。结果表明,该藻细胞周期分为流动和不动２个阶段。每一阶段主要以无性生殖产生孢子的方式完成增殖。正常条件下游动细胞主要产生２、４个,偶尔产生２、４个,偶尔产生８个游动孢子,游孢子从孢子囊释放后为游动细胞。环境不适时流动细胞以及流动孢子失去鞭毛转入不动阶段。不动细胞主要形成４、８个,偶尔也能形成２０多个不动孢子,该过程不一定     

Changes in the population structure of Calanus sinicus during summer–autumn in the southern Yellow Sea

Calanus sinicus is a calanoid copepod widely distributed in coastal waters of China and Japan, and oversummering strategies may have major impacts on their population dynamics which in turn affect local marine food web structure. The abundance, stage composition, and sex composition of the planktonic copepod C. sinicus were studied from August to October 2002 in the southern Yellow Sea to understand how its population recovers from the over-summering state. Results showed that C. sinicus had low reproduction in August due to high temperature, except in waters near the Cheju Island with rich food and moderate bottom temperature, but the reproduction rates here decreased in September–October as food availability declined. When temperature dropped in September–October, C. sinicus actively propagated in coastal shallow waters. However, reproduction rates of C. sinicus individuals inhabiting the Yellow Sea Cold Water Mass(YSCWM) remained low during the three months of the study. The percentage of C. sinicus females was high during the reproductive period, which suggests that the sex composition of adult C. sinicus may reflect whether or not the population is in the reproductive mode.Numerous fifth copepodite stage(CV) C. sinicus aggregated in the YSCWM in a suspended developmental stage during the three months of this study, and they potentially served as the parental individuals for population development when conditions became optimal for reproduction later in the year.     

Method for assessing the chronic toxicity of marine and estuarine sediment-associated contaminants using the amphipod Corophium volutator

Acute sediment toxicity tests do not test key life stage events such as moulting and reproduction and therefore do not reveal the longer-term effects of contaminant exposure. A laboratory method is described for determining the chronic toxicity of contaminants associated with whole sediments. The test is conducted using neonates of the estuarine amphipod Corophium volutator at 15 degrees C, salinity 25 psu and a 12 h light:12 h dark photoperiod. The endpoints are survival and growth after 28 days and survival, growth and reproduction of amphipods upon termination of test i.e. reproduction within all control vessels (ca 75 days). The sediment chronic toxicity test was used to investigate the effects of sediments spiked with environmentally relevant preparations of slightly weathered Alaskan North Slope crude oil, including a water-accommodated-fraction (WAF) and a chemically-dispersed (Corexit 9527) WAF. Sediment oil concentrations were quantified using ultra-violet fluorescence. The amphipods exposed to chemically dispersed oil had higher mortality and lower growth rates than control-, Corexit 9527- and WAF-exposed organisms, resulting in reduced reproduction. The described method supplements the standard acute sediment test and would be particularly useful when long-term ecological effects are suspected but acute tests reveal no significant mortality. The sediment chronic test reported herein has shown that sediment that was not evidently toxic during 10-day acute tests could have population-level effects on sediment-dwelling amphipods.     

有关石花菜Gelidium amansii Lamx生活史中几个问题的探索

自1980—1986年,我们在研究孢子育苗的同时,对石花菜生活史中的几个主要环节进行了较细致的观察和研究。用采孢子育苗的方法培育出雌、雄配子体和孢子体。也完成了石花菜生活史的循环培养。通过孢子育苗的培养,发现两种孢子的量和质,以及两种孢子苗有明显的差异。特别是从孢子萌发、生长的幼苗还有出芽繁殖。随着幼苗的生长又出现匍匐枝的繁殖,并继续繁殖下去,对于石花菜的栽培具有决定性的价值。我们认为在石花菜生活史图中,应增加上三种幼苗阶段出芽繁殖的支环和三种藻体匍匐枝繁殖的支环,更能反映出石花菜生活史的实质,对指导科研、教学和石花菜的栽培将产生更大的活力。     

光质对海带配子体生长发育影响的研究

以孢子水采苗的海带(Laminaria japonica)配子体为材料,研究了蓝光、绿光、红光对配子体生长,发育的影响.结果表明:蓝光对生长、发育的促进作用最大,绿光其次,红光对生长有促进作用,对发育的促进作用不大;在一定的光强范围内,配子体的生长速度都随着光强的提高而加快,当蓝光超过8001x、绿光超过16001x、...     

光照强度对白色霞水母(Cyanea nozakii Kishinouye)无性繁殖的影响

采用控制光照强度的方法,研究了不同光照强度对白色霞水母无性繁殖的影响。结果表明,400lx组螅状体的相对增长率、特定生长率和螅状体足囊、囊胞繁殖率均显著高于其它各试验组(P<0.05),呈现出400lx>800lx>1200lx>0lx的趋势。在设定的光照强度范围内,螅状体足囊、囊胞繁殖出现的时间随光照强度的减少而延迟。800lx组的足囊萌发率最高,但各试验组足囊萌发率之间无显著性差异(P>0.05)。试验期间始终是400lx组螅状体的横裂率最高,试验结束时,0lx组螅状体的横裂率最低。试验结果说明,适当的光照度对白色霞水母螅状体生长、螅状体足囊、囊胞繁殖和横裂生殖均有促进作用,强光条件或完全无光照条件不适宜白色霞水母螅状体的生长并可使横裂生殖延迟或受到抑制。     

Environmental risk assessment of alkylphenols from offshore produced water on fish reproduction

Concern has been raised over whether environmental release of alkylphenols (AP) in produced water (PW) discharges from the offshore oil industry could impose a risk to the reproduction of fish stocks in the North Sea. An environmental risk assessment (ERA) was performed to determine if environmental exposure to PW APs in North Sea fish populations is likely to be high enough to give effects on reproduction endpoints. The DREAM (Dose related Risk and Effect Assessment Model) software was used in the study and the inputs to the ERA model included PW discharge data, fate information of PW plumes, fish distribution information, as well as uptake and elimination information of PW APs. Toxicodynamic data from effect studies with Atlantic cod (Gadus morhua) exposed to APs were used to establish a conservative environmental risk threshold value for AP concentration in seawater. By using the DREAM software to 1) identify the areas of highest potential risk and 2) integrate fish movement and uptake/elimination rates of APs for the chosen areas we found that the environmental exposure of fish to APs from PW is most likely too low to affect reproduction in wild populations of fish in the North Sea. The implications related to risk management of offshore PW and uncertainties in the risk assessment performed are discussed.     

Characterization and Transcriptional Response of Ecdysone Receptor Gene in the Mud Crab Macrophthalmus japonicus: Effects of Osmotic Stress and Endocrine Disrupting Chemicals

Ocean Science Journal - The ecdysone receptor (EcR) induces hormonal pathways by binding ecdysteroids to other nuclear receptors for development, reproduction, and molting processes. To further...     

轮虫生产中两种益生菌的应用试验

鱼类在工厂化育苗中，用面包酵母进行褶皱臂尾轮虫(Brachionusplicatilis)的培养生产时，添加初始浓度为100×10     

A study on the biology of Cultellus scalprum

Ａ　ｓｔｕｄｙ　ｏｎ　ｔｈｅ　ｂｉｏｌｏｇｙ　ｏｆ　Ｃｕｌｔｅｌｌｕｓ　ｓｃａｌｐｒｕｍＣｈｅｎＰｉｎｊｉａｎ（ＲｅｃｅｉｖｅｄＪｕｌｙ８，１９９５ｉａｃｃｅｐｔｅｄＯｃｔｏｂｅｒ２０，１９９５）Ａｂｓｔｒａｃｔ：Ｔｈｉｓｐａｐｅｒｒｅｐｏｒｔｓｉｎ...     

Effects of Green Light on the Stress Response of Olive Flounder Paralichthys olivaceus under Clove Oil Anesthesia

Ocean Science Journal - Clove oil (CO) is an effective anesthetic. Many hatcheries and research studies use clove oil to immobilize fish for artificial reproduction and surgery to suppress their...     

坛紫菜生活史的研究现状及存在的问题

坛紫菜（Porphyra haitanensis）属暖温性海藻,是中国东南沿海的重要栽培物种,2011年度栽培面积达30余万亩。其生活史过程比较复杂,既有雌雄异体,也有雌雄同体;既存在无性生殖,也存在有性生殖;其能否产生单孢子也常常引起争议。为此,本文总结了坛紫菜的生殖及生活史的研究现状和存在的问题,旨在为坛紫菜的遗传育种提供一定的理论参考。     

加速南四湖大水面开发的途径

本文就加速南四湖大水域开发利用的必要性、紧迫性和现状做了分析,并提出今后发展应以大湖增、养殖为主,增、养、捕相结合的对策。利用湖区自然优势,充分发挥湖泊的生态效益、经济效益和社会效益。     

养殖比目鱼生殖及其调控机理研究进展

综述了养殖比目鱼生殖及其调控机理研究的最新进展,包括雌鱼卵巢发育及其外源激素和光温调控,雄鱼精巢发育及其外源激素和光温调控,性别分化的温度决定机制,早期性别鉴定方法等.旨在为我国比目鱼的养殖和研究提供科学依据.