2005～2013年辽东湾北部近海白色霞水母的数量分布

2004年中国北方渤海辽东湾白色霞水母(Cyanea nozakii)暴发,给辽东湾带来巨大的生态灾难。为了分析辽东湾白色霞水母的暴发原因,对2005~2013年每年5月下旬至7月下旬在渤海辽东湾北部近海进行的大型水母监测调查数据进行了分析。结果显示:辽东湾北部近海白色霞水母主要分布在辽东湾东北部和西北部近海的非河口水域,该水域属于辽东湾北部近海盐度较高的水域,体现出白色霞水母高盐的生态属性。2004~2013年夏季辽东湾北部近海海水盐度呈逐渐下降的趋势,2004~2013年辽东湾白色霞水母的数量也呈现逐渐减少的趋势,2010~2013年辽东湾北部近海未发现白色霞水母。研究结果表明:近几年辽东湾夏季海水盐度的持续偏低,是白色霞水母在辽东湾北部近海近几年数量偏少甚至未出现的主要原因之一。     

北戴河近岸海域水母暴发现象调查及防控建议

对2019年-2021年7月-8月北戴河近岸3海里范围海域水母暴发情况进行监测巡视及捕捞,并对调查结果进行统计分析.调查结果显示北戴河近岸海域水母种类主要有海月水母、沙蜇、海蜇、白色霞水母四类.近三年来海月水母暴发期缩短,捕捞量有减少趋势,白色霞水母暴发期较长,捕捞量逐年增加,成为水母捕捞重点防治对象.水母总捕捞量20...     

辽东湾爆发的大型灾害性水母经鉴定为白色霞水母

2004年在辽东湾水域一种大型灾害性水母首次大范围爆发性增殖，因其生长过程中分泌毒素并缠粘网具，对海洋渔业造成巨大负面影响，被称为继赤潮之后又一场生态灾难。2004年7月在海上调查时首先鉴定为霞水母，霞水母为属名，而非种名，在我国沿海已发现4种霞水母，分别为白色霞水母、     

白色霞水母各发育阶段的形态

对白色霞水母从受精卵到成体水母各发育期的形态进行了描述。受精卵发育成带纤毛的浮 浪幼虫，浮浪幼虫在定置前形成一种凸面的圆形浮浪幼体囊, 经脱囊狭窄柄部拉长进而变成一个细长颈瓶形状，萌发出4个触手成为早期螅状体；螅状体可产生足囊和通过产生匍匐茎形成囊胞进而发育成新的螅状体；横裂为典型的单碟型横裂；新释放的碟状幼体绝大多数为8个缘叶，8个感觉棍和8对钝圆的缘瓣，但畸形个体最多12个，最少6个缘叶，同时对海蜇与白色霞水母的碟状幼体形态进行了比较。成体水母伞径200～300 mm，大型个体超过500 mm。外伞表面光滑,近中央的伞顶上有许多密集的刺胞丛隆起, 8个缘叶，8个感觉棍,口腕非常发达，口腕上有大量刺细胞团。可根据感觉胃囊和触手囊是否连接、缘瓣水管的排列类型、外伞顶中央是否有刺细胞丛以及个体伞径和颜色对白色霞水母、发形霞水母、棕色霞水母和紫色霞水母进行鉴别。     

四种大型水母横裂生殖的差异与其种群数量变动的初探

在实验室培养了4种大型水母:海蜇、海月水母、白色霞水母及沙海蜇的螅状体.在相同的生态环境下,观察了这4种螅状体的横裂生殖, 其横裂生殖率:海蜇100%、海月水母100%、白色霞水母0%、沙海蜇0%.经过横裂生殖螅状体的存活率:海蜇20%、海月水母100%.未横裂生殖螅状体的存活率为100%,同时探讨了这4种大型水母的种群数量变化原因.     

霞水母机械加工方法的探讨

霞水母的大范围暴发不仅严重影响了张网等渔业的作业,而且对沿海海域造成了生态危机。利用机械手段代替手工方法实现霞水母的加工、开发,不仅可提高渔民的经济收益,而且有利于霞水母资源得到进一步开发。在海蜇加工原理基础上,通过设计、开发霞水母切丝装置、脱水装置,实现了霞水母去污与清洗→机械切丝→机械脱水→腌制→装箱上市的加工工艺。实验表明,机械加工霞水母具有较好的加工性能,具有广泛的社会和应用价值。     

秦皇岛海域水母类特征分析

根据2009-2011年秦皇岛海域浮游生物、大型水母拖网监测数据及相关文献和历史调查资料,对该海域出现水母、浮游生物的特征进行了统计分析。结果如下:秦皇岛海域出现的水母有30种,其中刺胞动物门2纲5目17科,栉水母门1纲1目1科;大型水母包括沙蛰、海蜇、海月水母、白色霞水母四种,对滨海旅游业造成一定影响。近年来秦皇岛海域浮游植物物种数量和密度未发生显著变化,浮游动物物种数量和密度变化也不大。     

霞水母(Cyanea nozakii Kisninouye)暴发与海洋生态之关联性探讨

霞水母在我国东黄海水域大范闱暴发已成为一大公害．弄清其暴发原因是治理的基础。本文在对霞水母繁殖、生长，发育习性分析基础上，提出引发霞水母灾害的四方面致因：1、海洋渔业资源的衰竭导致其住生态系统中的种间竞争损耗率降低；2、中上层低值鱼类资源量的急剧下降直接导致海域巾小型浮游动植物的生物量大幅升高，为霞水母生长、发育提供了丰富的饵料基础，3、夏季休渔制度的实施，减少了捕捞活动干扰，为霞水母生长、发育创造了平静的海域环境；4、霞水母捕捞数量相对较少．其资源数量呈强势增长据此，就治理对策提出了相应的建议。     

4 种大型水母类ITS-5.8S rDNA 序列分析及其在钵水母类系统分析中的应用

由于钵水母类生物地理学研究的缺乏以及不同时期形态变异较大等原因,对其分类鉴定比较混乱和困难。为弥补形态学分类的缺陷,采用通用引物PCR扩增法,测定了分布于黄海北部和辽东湾海域海蜇(Rhopilema esculentum)、沙蜇(Nemopilema nomurai)、海月水母(Aurelia sp.)、白色霞水母(Cyanea nozakii)4种大型水母的ITS-5.8S rDNA序列,同时利用Gen Bank数据库中已有的钵水母纲(Scyphomedusae)ITS1(the Ribosomal First Internal Transcribed Spacer)同源序列对其进行序列分析并构建系统树,分析ITS1序列片段在大型水母种类鉴定方面的可行性及其在钵水母类系统及演化中的应用。结果显示,4种水母的ITS-5.8S rDNA序列变异较大且具有明显的序列长度多态性,序列长度范围675~833 bp。钵水母纲很多种类的ITS1序列具有种内长度多态性现象,这种长度多态性主要是由于微卫星重复次数不同所造成的。钵水母纲科间遗传距离为0.295~0.491,种间遗传距离为0.024~0.812;除白色霞水母和海蜇外,种内个体间遗传距离为0.000~0.099。采用ML法(maximum likelihood)和贝叶斯法(Bayesian)构建的分子系统树拓扑结构不完全相同且与形态分类学的观点不太一致。研究表明,ITS基因序列在钵水母纲不同阶元间变异较大,适合于钵水母纲种类鉴定和属内种间水平的系统进化研究。     

绿鳍马面鲀(Navodon septentrionalis)对4种大型水母的捕食行为

以绿鳍马面鲀为研究对象,通过室内受控实验,比较研究了其对我国沿海4种常见大型水母(海蜇、沙海蜇、海月水母和白色霞水母)的捕食差异。结果显示,体重为(215±20)g的绿鳍马面鲀对海月水母的捕食能力最强,日均最大摄食量为(150.7±18.6)g/fish,其次是海蜇和白色霞水母,日均摄食量分别为(129.7±11.6)和(120.0±19.3)g/fish,对沙海蜇的摄食量最少,为(92.5±11.3)g/fish;绿鳍马面鲀对海月水母与海蜇摄食量主要受投喂量影响,与规格无关,当投喂量小于其最大捕食量时,绿鳍马面鲀可捕食其周围所有水母,当投喂量超过其最大摄食量并继续增加时,绿鳍马面鲀摄食量保持不变,但残余水母的触手和伞部边缘均被啃食,继而导致水母摄食能力丧失,难以继续生存;在适口饵料冰鲜玉筋鱼充足的情况下,绿鳍马面鲀对水母具有明显的摄食偏向性,与仅投喂水母实验组相比,其对海月水母和海蜇的日均摄食量仅降低了20.2%和16.9%。研究结果表明,绿鳍马面鲀对上述4种水母皆能捕食。     

Elemental fingerprinting in otoliths reveals natal homing of anadromous Baltic Sea pike (Esox lucius L.)

We examined the element pattern in the otoliths of a migratory fish species that inhabit the coastal areas in the brackish of the Baltic Sea. The northern pike (Esox lucius) show migratory behaviour, spawning in streams and rivers and foraging in the sea. We examined spawning migration in four nearby streams in the south‐west part of the Baltic. Otolith analysis by microPIXE revealed unique elemental patterns (Sr, Zn, Br, Co and Mn) for the juveniles in each of the different streams. The strontium signal in the otolith of the juveniles was used as an indicator of freshwater origin and the time spent in the stream. Adult pike in their migrating spawning phase were caught in each of the streams. The elemental composition in otoliths in their freshwater phase (using juvenile pike in the streams as references) was determined. A principal component analysis showed that the elemental fingerprint during the freshwater phase several years back in time was similar for the adult fish and for juveniles inhabiting the stream today. The results indicated natal homing of the adults to a specific stream, a conclusion that was strengthened by the fact that marked fish returned to spawn over consecutive years. Anadromous pike in the Baltic Sea may thus be divided in subpopulations. The results of the study may have implications for fishery management, as pike in the Baltic Sea cannot be seen as homogenous population.     

The in vivo incorporation and metabolism of [1-14C] linolenate (18:3n-3) in liver, brain and eyes of juveniles of rainbow trout Oncorhynchus mykiss L and gilthead sea bream Sparus aurata L.

Accumulation of docosahexaenoic acid (DHA; 22:6n-3) in brain and eyes during development has been demonstrated in fish but it is not clear whether liver or neural tissues themselves are of greater importance in the biosynthesis of DHA from dietary 18:3n-3. In the present study, we investigated the in vivo metabolism of intraperitoneally injected [1-¹⁴C]18:3n-3 in liver, brains and eyes of young juvenile fish. Metabolism was followed over a 48h time-course in order to obtain dynamic information that could aid the elucidation of the roles of the different tissues in the biosynthesis and provision of DHA from dietary 18:3n-3. The study was performed in both a freshwater fish, rainbow trout Oncorhynchus mykiss L and a marine fish, gilthead sea bream Sparus aurata L to determine the effect that low or limiting5-desaturase activity may have in this process. As expected, the results showed that although the sea bream incorporated more 18:3n-3 into its lipids, metabolism of the incorporated fatty acid by de saturation and elongation was generally greater in the trout. In liver, the percentages of radioactivity recovered in tetraene and pentaene products were greater in trout than in sea bream although there was no difference in hexaenes. In contrast, the re covery of radioactivity in DHA was significantly greater in brain in trout compared to sea bream. In both species, the percentage of radioactivity recovered in desaturated/elongated products was much lower in liver than in brains and eyes, but that percentage increased over the 48h time-course. In trout though, the highest percentages of desaturated products in brain and eye were observed after 12 and 24h, respectively. However in sea bream the highest percentages of desaturated products in the neural tissues were observed after 24-48h. Radioactivity was recovered in 24:5n-3 and 24:6n-3, intermediates in the 4-independent ("Sprecher shunt") pathway for the synthesis of DHA, in both species, especially in the brain and eyes. Overall, although the results cannot eliminate a role for liver in the biosynthesis and provision of DHA for developing neural tissues in fish, they suggest that DHA can be synthesised in fish brain and eye in vivo.     

Ontogenetic changes of alpha-melanocyte-stimulating hormone (α-MSH)-like immunoreactivity in the brain and hypophysis of a scyliorhinid dogfish (Scyliorhinus torazame): An immunohistochemical study

Ontogenetic development of α-MSH-IR (alpha-melanocyte-stimulating hormone-like immunoreactivity) in the brain and hypophysis of a scyliorhinid dogfish (Scyliorhinus torazame) was studied immunohistochemically. α-MSH-IR first appeared in the hypothalamus of the brain in embryos at the 43-mm stage. Thereafter, α-MSH-positive cells and fibers gradually increased in number in mainly the tuberculum posterius of the hypothalamus during the embyonic periods. In the post-hatching juveniles at the 95-mm and 125-mm stages, α-MSH-positive structures in the brain were comparable to those in adult fish, although the distributional range of α-MSH-IR structures in the brain was less extensive than those in adult fish. In the hypophysis, α-MSH-positive cells first appeared in the caudal part of the adenohypophysis at the 54-mm stage, approximately coincident with the onset of pigmentation in the skin. During ontogenesis, the MSH-producing cells increased in number straightforwardly in the adenohypophysis. This revised version was published online in August 2006 with corrections to the Cover Date.     

Immunoreactive somatolactin cells in the pituitary of young,migrating, spawning and spent chinook salmon,Oncorhynchus tshawytscha

Immunocytochemical techniques using an antiserum to cod somatolactin (SL) demonstrated the presence of SL cells in the intermediate lobe of the pituitary in Oncorhynchus tshawytscha. The cells were small in yearling fish. Two groups of maturing fish were studied. In the spring run salmon collected in April and May during the upstream migration, the SL cells appeared stimulated. In September, during spawning, SL cell stimulation was maximal with indices of hypertrophy and degranulation often more marked in females than in males. In the other group, salmon of the fall run collected in the Pacific Ocean in August had well developed gonads, large gonadotropes and abundant SL cells. In spawning salmon (September) the SL cells were stimulated, mainly in females. However, the final stimulation was less intense than in spring run spawning fish. The SL cells were smaller, without evident granule release, but still abundant in spent salmon of the fall run caught at the end of November. Various factors (time spent in rivers before spawning, starvation, decalcification, stress, hypothalamic influences) were considered which might explain differences between spring and fall run salmon. These observations suggest that SL may play a role in the control of gonadal maturation in chinook salmon as it may also do in sockeye and chum salmon previously studied, and that SL cells may be sensitive to the ambient salinity.     

Food sources for the bivalve Corbicula japonica in the foremost fishing lakes estimated from stable isotope analysis

ABSTRACT:   Carbon and nitrogen stable isotope ratios in tissue of the bivalve corbicula Corbicula japonica and particulate organic matter (POM) were measured in Lake Jusan, Lake Ogawara and Lake Shinji, which are the foremost fishing grounds for the corbicula in Japan, to determine their food sources. The bivalves in Lake Ogawara and Lake Shinji showed enriched isotope composition, while those in Lake Jusan were depleted. In addition, the difference in the isotope ratios between the sampling sites was remarkable in Lake Jusan. Chlorophyll concentrations were significantly higher in Lake Ogawara and Lake Shinji than those in the inflow rivers, although that in Lake Jusan was equivalent to that in the river. Residence time of river water was estimated at 1 day, 455 days and 88 days in Lake Jusan, Lake Ogawara and Lake Shinji, respectively. These values indicate that the bivalves in Lake Ogawara and Lake Shinji assimilate autochthonous phytoplankton, while those in Lake Jusan assimilate terrestrial matter in the upper reaches and marine phytoplankton in the lower reaches because of low production in the lake.     

Comparative analysis of the predominant carotenoids and chemical components in the common and orange‐muscle mutant of Haliotis gigantea

The Xishi abalone (Haliotis gigantea) is an economically significant aquaculture species in southern China. We identified a novel orange‐muscle mutation present in less than 2% of the cultured population. High‐performance liquid chromatography and electrospray ionization mass spectrometry identified zeaxanthin and β‐carotene as the two main pigments present in the orange‐muscle abalone. The concentrations of zeaxanthin and β‐carotene detected in the orange‐muscle abalones were significantly higher than those detected in the common abalones (p < 0.01). Notably, the concentration of zeaxanthin was approximately 16.5 times higher in orange‐muscle abalones than in common abalones, which was also the species with highest carotenoid content reported in shellfish to date. Furthermore, the contents of total amino acids and essential amino acids in the orange‐muscle abalone were higher than that in the common abalone, though not significantly, while the content of non‐essential amino acids was significantly higher in the orange‐muscle abalone than that in the common abalone (p < 0.05). The saturated fatty acid content in the orange‐muscle abalones was slightly lower than that in the common abalones, and the unsaturated fatty acid content was higher in the orange‐muscle abalones than that in the common abalones. These results could provide a basis for characterizing the mechanism by which carotenoids accumulate in abalones and further guide the breeding of abalone with orange‐muscle mutants in the future.     

对虾养殖池塘微藻群落结构的调查与分析

分别于2005年秋、2006年春对广东省湛江市东海岛的对虾集约化养殖池(高位池)、半集约化养殖池(土塘)及其引水渠中水体的微藻群落结构进行调查和分析。结果表明,在所调查的对虾池塘中共检出微藻47种,其中春季检出微藻28种,秋季检出微藻21种。主要优势种是颤藻(Oscillatoria sp.)和啮蚀隐藻(Cryptomonas erosa Ehr.)。微藻的多样性指数(H′)平均值为春季东南土塘2.29,东南高位池1.42,东山土塘1.12;秋季东南高位池2.14,东山土塘1.62,而2季节引水渠则处于0.92~3.72之间。对虾池塘微藻平均密度秋季高于春季。     

2005年东海及黄海部分海域表面水温状况分析

东、黄海表面水温分布状况对中国沿海的生态系统有很大的影响,因为研究表面水温的年变化对了解生态系统的变化很有意义。本文分析了2005年东海及黄海部分海域的表面水温状况。研究表明不同的水团具有不同的水温年变化特点。2005年暖流区域的表面水温总体上与多年平均状况相比差别不大。虽然显示出上半年较冷,年末较热的现象,但只是在秋初一段时间内暖流区的表面水温比多年平均值高一些,而显示出较强的势力,年中的其余时间与多年平均的差别不大。沿岸海域的水温变化比较复杂,福建沿岸表面水温与多年平均状况差别不大;浙江沿岸及长江口邻近海域除春季的一段时间外,年中大部分时间的水温比多年平均值偏高,特别是在夏秋季节,偏高持续的时间既长,且幅度也较大;江苏北部沿岸及山东沿岸的表面水温与多年平均值相比差别不大,除在夏季一段时间内有偏高现象外,其余时间都呈略微偏低状态。中间水体的表面水温与多年平均值相比,在2005年的前3季的状况比较一致,都呈现了初冬偏暖,春季偏冷,夏季略微偏热的变化特征;秋季则南部的区域偏暖,北部区域与多年平均状况差不多。     

Spatial distribution and feeding habits of Pacific cod (Gadus macrocephalus) larvae in Mutsu Bay, Japan

The spatial distributions and feeding habits of Pacific cod ( Gadus macrocephalus ) larvae, and the spatial distributions of copepod nauplii and copepodites, their main prey, were examined in Mutsu Bay from February to March during 1989–92. Yolk-sac larvae were caught at 30–45 m depth at the bay mouth. Larvae without yolk were collected at 8–45 m depth at the bay mouth and the inner part of the bay, and large larvae were chiefly found in the bay. This geographical pattern in larval size may have been because of transport to the inner part of Mutsu Bay by the Tsugaru Warm Current. The dominant taxa of copepod nauplii and copepodites in the diet and the environment changed each year. Larvae fed mainly on abundant taxa in the environment, suggesting that larvae are opportunistic feeders. Nauplii and copepodites were abundant in the bay, especially in 1992. Copepodites were slightly more abundant in the diet of cod larvae in 1992 than in 1991, but this difference was smaller than in the environment. In addition, larvae with empty digestive tracts were scarce in 1991 and 1992. Prey concentrations in the bay in 1991 and 1992 seem to have been high enough to sustain most Pacific cod larvae.     

盐度、pH对文蛤肌肉、鳃、外套膜HSP70基因表达的影响

为探讨池塘养殖文蛤的适宜盐度和pH范围,以β-actin为内参基因,采用实时荧光定量聚合酶链式反应技术,检测不同盐度(16、18、20、22、24)和pH(6.7、7.7、8.7、9.7、10.7)梯度下文蛤肌肉、鳃、外套膜中HSP70基因mRNA的表达水平。结果显示,盐度16、18、22、24处理组肌肉中HSP70基因的表达量显著高于盐度20的对照组(P0.05);除盐度18组鳃和盐度24组外套膜HSP70基因的表达量与对照组差异不显著外(P0.05),16、18、22、24盐度组鳃和外套膜中HSP70基因的表达量均显著高于对照组(P0.05)。pH 6.7、7.7、9.7、10.7处理组肌肉、鳃、外套膜中HSP70基因的表达量与pH为8.7的对照组差异显著(P0.05)。试验结果表明,超出一定盐度、pH范围,可显著诱导文蛤肌肉、鳃、外套膜中HSP70基因的过量表达,研究结果可为池塘文蛤的健康养殖提供参考。