Taxonomy and zoogeography of euchaetid copepods (Calanoida,Clausocalanoidea) from Korean waters,with notes on their female genital structure

Euchaetid copepods (Calanoida, Clausocalanoidea) were collected from the southeastern region of Korea and the East/Japan Sea from June 2007 to August 2008. Seven species were found and redescribed in this study: five species from the genus Euchaeta (E. concinna, E. indica, E. longicornis, E. plana and E. rimana) and two species from the genus Paraeuchaeta (P. elongata and P. russelli). Using scanning electron microscopy, we observed detailed taxonomic features with special references to their genital structure. The euchaetid copepods show speciesspecific characteristics on their genital structures, in particular on the shapes of genital operculum and genital flange. Their zoogeographies were also discussed. They can be regarded as an indicator species of the Tsushima Warm Current and East Sea Intermediate Water.     

Five <Emphasis Type="Italic">Oncaea</Emphasis> species (Copepoda,Poecilostomatoida, Oncaeidae) from the Korean waters,with notes on the spatio-temporal distribution of Korean oncaeid species

Five Oncaea species were recorded on the basis of specimens collected using three type nets from the South Sea and the East Sea of Korea. These included the clevei-group of one species (O. clevei) and the venusta-group of four species (O. media, O. mediterranea, O. scottodicarloi, O. waldemari). The former has a dorsoposterior projection on the second pedigerous somite, while the latter do not bear any dorsal projection on the somite. Also, their spatio-temporal distribution are discussed in relation to temperature-salinity.     

Spatio-temporal variability of small copepods (especially Oithona plumifera) in shallow nearshore waters off the south coast of South Africa

Although small copepods are one of the main dietary sources for many commercially important fish, their role in the pelagic trophic dynamics has traditionally been underestimated due to the methodology commonly used in plankton sampling. Temporal variation in abundance of adults and nauplii of small copepods (particularly Oithona plumifera) in nearshore waters on the south coast of South Africa was investigated fortnightly over 14 months at site (km) and location (100 m) scales. Sampling was within <500 m of the shore, where depth was ca. 10 m, using vertical hauls of an 80-μm mesh plankton net from 1 m above the seabed to the surface. Twenty-seven adult copepod taxa were recorded, but Oithona spp. was consistently the most abundant. Taxon richness was 7–19 on each sampling occasion. There was strong temporal variation (Oithona varied between 0 and 2300 m⁻³), but much of this was short-term variability (e.g. between consecutive sampling sessions), with no seasonality or other long-term discernable patterns. There were periods of consistently low numbers, but very high numbers often followed samples with low abundances. Nor was there spatial structure at the location scale, though numbers differed between sites. Despite considerable variability at the location scale within sites, Kenton consistently showed higher densities than High Rocks. Separate analyses, with Bonferroni adjustment, showed that this difference was significant on eight out of 21 occasions for Oithona, six for other pelagic copepods and three for nauplii. This suggests that hydrodynamics favour aggregation of plankton at Kenton. A high degree of short-term variability, with a tendency for aggregation of small zooplankton at certain sites has implications for both pelagic processes and food-web links between the benthic and pelagic environments.     

三亚大东海砂质潮间带小型底栖生物的时空分布及影响因素

于2015年和2016年对三亚大东海砂质潮间带进行了季节性的调查,对小型底栖生物及其所处的沉积环境进行了研究,探讨了小型底栖生物的丰度、生物量和群落的时空变化及其与环境变量的关系。共鉴定小型底栖生物类群11个,优势类群为海洋线虫类与桡足类(二者占总丰度83.13%);小型底栖生物年平均丰度为(595.77±442.72)ind·10cm~(–2),小型底栖生物2015年12月的平均丰度为(768.70±533.22) ind·10cm~(–2), 2016年6月平均丰度为(422.85±236.42) ind·10cm~(–2)。丰度分布呈现明显的季节和潮区差异。相关分析结果表明pH、偏态系数与小型底栖生物的丰度呈极显著的负相关,分选系数、中值粒径与之呈极显著的正相关性。小型底栖生物的丰度随季节变化趋势为冬季夏季。食物丰度、溶氧量升高与沉积物粒径的变化是冬季桡足类丰度的大幅增加的主要原因。TWO-WAY ANOVA与ANOSIM结果显示,潮带对小型底栖生物丰度和群落结构的影响在冬季显著。SIMPER分析结果显示,此差异主要来源为桡足类和线虫类。BIOENV分析结果显示,溶氧量和分选系数的组合最能解释这种差异。这一结果可能是由于高、中潮带的人为干扰与砂滩的清理作用导致。夏季潮带间丰度与群落结构差异不显著,pH、盐度、叶绿素含量是影响其分布的主要原因。研究结果可为砂质滩小型底栖生物的研究提供基础数据,也可为全球气候变化背景下砂质潮间带的保护、开发和利用提供科学依据。     

Spatial spring distribution of the copepod Eurytemora affinis (Copepoda,Calanoida) in a restoring estuary,the Scheldt (Belgium)

The spatial spring distribution of Eurytemora affinis (adults and C5) in the Scheldt estuary (Belgium) brackish and freshwater reaches was studied in between 1996 and 2007. The bulk of the E. affinis population being generally situated in the brackish water reach (salinity > 0.5); we studied which environmental factors are responsible for its recent sporadic occurrence in the freshwater estuarine reach. Using PLS analysis, it is shown that its presence upstream is limited by a sufficient oxygen concentration (>4 mg l⁻¹) that is associated with temperature. Not only are the environmental conditions in the upstream zone important, but also the frequent presence of an O₂ minimum zone in the mid-estuary (O₂ min < 1.3 mg l⁻¹) seems to block the movement of the downstream E. affinis population in an upstream direction. Occasionally, the bulk of the population is however situated upstream. During these periods, high E. affinis abundance was also observed in the Durme tributary. Our findings suggest the possibility to use E. affinis as an “indicator” species of water quality, but also lead us to stress the necessity to consider conditions over the entire estuary when studying restoration effects, not exclusively in the zone of interest.     

南海腹突平头水蚤新记录(甲壳纲:桡足亚纲:平头水蚤科)

本文基于南海采集的浮游动物标本,详细描述了腹突平头水蚤Candacia varicans Giesbrecht,1892的雌雄个体形态分类特征。本文报道腹突平头水蚤雄性个体是中国海的首次记录。腹突平头水蚤雄性在形态上与武平头水蚤和短平头雄性个体相似,但腹突平头水蚤可以通过以下几个特征与上述两个物种区分：1）头胸部：末胸节后侧角尖锐,左右对称;2）生殖节：右侧下缘具一个指向后方的小突起;3）第五胸足：右足第3节近末端背面具1片状突起。     

中国海域南褐虾属种类记述(甲壳动物亚门, 十足目, 褐虾科)

为了搞清中国海域存在的南褐虾(Philocheras)的生物多样性和地理分布,作者通过形态学特征系统研究了中国科学院海洋研究所海洋生物标本馆馆藏的南褐虾标本,此标本主要采自中国海域,也检查了部分采自菲律宾海域的标本。本研究和相关文献的结果表明:中国海域存在的南褐虾共计7种,包括作者描绘的4种以及在其他文献中提到的3种。作者对本次研究的4种南褐虾提供了详细的鉴别特征、地理分布、外部整体图和附肢结构图,并对中国海域存在的7种南褐虾提供了检索表。     

棕囊藻属(Phaeocystis)的种类多样性及地理分布特征研究进展

棕囊藻(Phaeocystis)是全球海洋广泛分布的有害藻华原因种,也是海洋初级生产力的重要贡献者,在极地和近海地区的碳、硫元素的生物地球化学循环、食物网结构及全球气候变化中都具有极其重要的作用.由于个体微小,形态特征观察困难,在常规观察中很容易被忽略.同时多数棕囊藻具有复杂的异型生活史,具有多种不同细胞形态,因此其传...     

Trophic position of Calanus finmarchicus (Copepoda, Calanoida) in the Trondheim Fjord

The trophic position of Calanus finmarchicus in the Trondheim Fjord in 2004 was determined through stable isotope analyses. Wild specimens were sampled monthly in the fjord and δ¹³C and δ¹⁵N signatures of the developmental stages from CIII to adults were measured. There were statistically significant differences in the δ¹³C and δ¹⁵N signatures of three identified groups: overwintered parental generation, developing new generation and new generation preparing for overwintering. C. finmarchicus individuals raised in a laboratory on a pure algal diet (Dunaliella tertiolecta and Isochrysis galbana) provided stable isotope signatures for purely herbivorous copepods. With these signatures as comparison, the trophic position of C. finmarchicus in the Trondheim Fjord in 2004 was determined as trophic level 2.4, thus indicating omnivory under natural conditions. Additionally, our data suggest that seasonal differences in the δ¹³C signatures of C. finmarchicus are due to the varying lipid content of the different developmental stages.     

Oceanic distribution and life cycle of Calanus species in the Norwegian Sea and adjacent waters

The distribution and demography of Calanus finmarchicus, C. glacialis and C. hyperboreus were studied throughout their growth season on a basin scale in the Norwegian Sea using ordination techniques and generalized additive models. The distribution and demographic data were related to the seasonal development of the phytoplankton bloom and physical characteristics of water masses. The resulting quantified relationships were related to knowledge on life cycle and adaptations of Calanus species. C. finmarchicus was the numerically dominant Calanus species in Coastal, Atlantic and Arctic waters, showing strong association with both Atlantic and Arctic waters. C. hyperboreus and C. glacialis were associated with Arctic water; however, C. glacialis was occasionally observed in the Norwegian Sea and is probably an expatriate advected into the area from various origins. Demography indicated one generation per year of C. finmarchicus, a two-year life cycle of C. hyperboreus, and both one- and two-year life cycles for C. glacialis in the water masses where they were most abundant. For the examined Calanus species, young copepodites of the new generation seemed to be tuned to the phytoplankton bloom in their main water mass. The development of C. finmarchicus was delayed in Arctic water, and mis-match between feeding stages and the phytoplankton bloom may reduce survival and reproductive success of C. finmarchicus in Arctic water. Based on low abundances of C. hyperboreus CI–III in Atlantic water and main recruitment to CI prior to the phytoplankton bloom, we suggest that reproduction of C. hyperboreus in Atlantic water is not successful.     

西南大西洋阿根廷滑柔鱼资源时空分布研究

通过了解西南大西洋阿根廷滑柔鱼(Illexargentinus)资源丰度年间变化规律,从而对阿根廷滑柔鱼的资源可持续开发与管理打下基础。作者根据2012～2017年西南大西洋阿根廷滑柔鱼生产统计数据,利用灰色关联评价等数理方法对西南大西洋资源渔场的时空分布特征进行了分析。结果表明,2012～2017年间西南大西洋阿根廷滑柔鱼渔场重心主要在经度上分布于58°W～63°W海域,纬度主要集中在41°～44°S、47°～48°S两个区域,高平均网次产量(10 t/网)的海域主要在57°W～67°W、41°S～42°S和57°W～67°W、44°S～50°S海域。灰色关联度表明:6年间,以2015年滑柔鱼资源状况最好,其次是2014年,2012年最差,2013年、2016年和2017年处于中间水平。利用灰色关联分析的阿根廷滑柔鱼资源丰度变化趋势可用于其资源的可持续开发与管理。     

Arm regeneration frequency in eight species of ophiuroidea (Echinodermata) from European sea areas

Eight ophiuroid species, six from the northern Kattegat-eastern Skagerrak and three from the northern Adriatic Sea, were examined for regeneration of arms. The species were separated into groups based upon mode of feeding and habitat. Comparison between groups collected in the northern Kattegat-eastern Skagerrak showed that infaunal suspension- and deposit-feeding species (Amphiura filiformis and A. chiajei) had significantly more scars per arm (mean number 0.78) than epibenthic suspension feeders (Ophiothrix fragilis and Ophiocomina nigra, 0.29) or epibenthic carnivores and deposit feeders (Ophiura ophiura and O. albida, 0.13). Spatial variation in arm regeneration incidence was found between sampling sites in the northern Kattegat-eastern Skagerrak for Amphiura filiformis and in the northern Adriatic Sea for Ophiothrix quinquemaculata. The ash-free dry weight (AFDW) and nitrogen (N) contents were measured in arms of six species of brittle-stars from the northern Kattegat-eastern Skagerrak. Differences between species were found, with highest concentrations of AFDW and N in Amphiura filiformis, intermediate in A. chiajei, Ophiocomina nigra and Ophiothrix fragilis, and lowest in Ophiura ophiura and O. albida. As the infaunal suspension- and deposit-feeding brittle-stars (Amphiura spp.) had the highest proportions of damaged arms and highest AFDW and N contents in their arms in this comparison, it is suggested that selective cropping of arms by demersal fish is the main cause of arm damage on Amphiura spp. in this area.     

Three species of Ditrichocorycaeus (Copepoda, Cyclopoida, Corycaeidae) from Korean waters, with new identification parameters

Three species of Ditrichocorycaeus [D. dahli (Tanaka, 1957), D. lubbocki (Giesbrecht, 1981), and D. subtilis (Dahl, 1912)] are first redescribed from southern area of Jeju Island, Korea. Morphological details such as mouthparts, ornamentation of genital double-somite, spine lengths of legs, and proportional lengths of caudal setae, are provided as new identification keys separating each species within Ditrichocorycaeus and/or each genus within Corycaeidae. In particular, the number and location of each segment on the body and antenna are re-examined and precisely defined. Also, few valid morphological characters of this genus distinguishing it from other genera are newly proposed as follows: 1) prosomes of both sexes are five-segmented; 2) basis of maxilliped with relatively longer proximal seta than in other genera.     

Assessment of introduced Kappaphycus (Solieriaceae, Rhodophyta) species relationships in China with molecular markers

Due to morphological plasticity and paucity of diagnostic morphological characters, the taxonomy of Kappaphycus gets more and more confused with the expanding of commercial cultivation. In this study, the phylogenetic relationship of 13 strains of introduced Kappaphycus species in China was defined using DNA molecular markers, such as 18S rDNA, rbcL and cox2-cox3 spacer region. The resolutions obtained by three different molecular markers were compared: both cox2-cox3 spacer region and rbcL sequences are eligible in interspecies identification of Kappaphycus, whereas cox2-cox3 spacer region is more variable than rbcL sequence. There is several basepairs’ discrepancy among 18S rDNA sequences, while it is 100% identical among both cox2-cox3 spacer region and rbcL sequences of the ten strains of K. alvarezii. We suppose that 18S rDNA sequence can provide more information in biogeography study of Kappaphycus than other two DNA sequences.     

中国福建省红树林湿地中自由生活海洋线虫(联体线虫科)的2个新种

本文描述了中国福建省红树林湿地中自由生活海洋线虫的2个新种。Sabatieria conicoseta sp.nov.的主要特征是：具有短的锥形体刚毛、12-15个管状的肛前附器以及长度为12-15 μm的直的引带突起。Dorylaimopsis papilla sp.nov.的主要特征是：交接器中部具有角质化带状隔膜,近端头状具一小钩,其长度为肛门所在位置体直径的1.5–1.8倍,具有长度为37-40μm的背尾指向的引带突起。泄殖孔前具16-18个微型乳突状的肛前附器。     

中国东南海域拟菱形藻属的新记录种和产毒种

拟菱形藻属（Pseudo-nitzschia）物种是一类备受关注的海洋有毒有害硅藻,我国相关研究仍然不足,已报道的物种多样性偏低,产毒物种也较少。为了解我国海域拟菱形藻属的物种多样性,阐述产毒物种信息,在我国东南海域建立了8个拟菱形藻单克隆培养株系,结合形态学和分子系统学数据,鉴定到2个物种:环孔拟菱形藻（Ps.circumpora C.H.Lim,C.P.Leaw&P.T.Lim）和多列拟菱形藻[Ps.multiseries（Hasle） Hasle],其中环孔拟菱形藻是我国的新记录种。利用高效液相色谱-质谱联用法检测了藻株的多莫酸（domoic acid,DA）特征,在5个多列拟菱形藻株系中检测到DA,单细胞产毒水平为1.01~96.11 fg。此外,利用卤虫（Artemia salina L.）和强额拟哲水蚤（Paracalanus crassirostris Dahl）对多列拟菱形藻的产毒株系（MC4177）进行诱导,发现能够提高其单细胞产毒水平,提高幅度在26~55倍。     

The first record of two species of leptocephali of the genusSaurenchelys (nettastomatidae, anguilliformes) from Korea

Leptocephali of the genusSaurenchelys in the family Nettastomatidae were collected from the coastal area of Pohang, Korea and described as the first record from Korean waters.S. stylura andS. lateromaculatus are characterized by two intestinal swellings, the pattern of pigments in the notochord, and by smaller pectoral fins than those of other genus. They are very similar to each other but they are distinguished by the pattern of pigments in the notochord and the intestinal swellings.     

安达曼海泰国水域的立方水母Chiropsoides属分类辨析

采集于泰国西南部安达曼近岸海域的一种立方水母Chiropsoides buitendijki,伞部呈典型的箱式、触手单侧分支,并缺乏幅间沟。触手带型呈1–3–2–3–2–3–2–3–1（1-主带,2-粗副带,3-细副带）。18S核糖体基因序列分析证实了其分类地位。同时,16S线粒体基因序列揭示样品内存在一定的遗传分化,说明该种内可能存在不同的群体,值得进一步研究。