浮游胶质被囊动物暴发机制及海洋碳泵效应

滤食性浮游被囊动物在开阔大洋和沿海海域中大量存在,通过黏液网来大量过滤海水浓缩食物颗粒以供种群快速增殖,是生物碳泵的关键组成,对海洋生物地球化学循环和生态系统能量流动均有重要意义。文章从浮游被囊动物生物学特征、植食性滤食作用、生活史特异性等方面综合论述了国内外关于浮游被囊动物在摄食海洋微型生物、调节海洋生物碳泵(biological carbon pump,BCP)和改变微型生物群落结构以及联系深海食物网等方面的作用。概括了国内外影响浮游被囊类暴发的食物因素、生活史特征、海洋动力过程及气候变化等相关研究进展。浮游被囊动物通过黏液过滤打包真光层微型生物,产生的粪便球和胶质死体快速沉降而输出成为胶质碳泵,从而增加BCP效率,改变微型生物碳循环途径;作为上层海洋生态系统与深海生态系统的媒介,胶质坠落在深海群落和底栖动物食物网中扮演重要作用。文章最后总结了其他胶质碳泵的相关研究进展,并提出在全球变化背景下,未来的研究应该更多地着眼于动力过程对不同生活史阶段浮游被囊动物的垂直移动和集群的影响,并将过滤摄食对微生物群落影响及繁殖策略响应与海洋物理、化学和生物环境多维度联系起来,全面解释浮游被囊类暴发的内在和外在机制,有助于准确评估海洋被囊类胶质碳泵效率及其对全球变化的响应。

南海芋螺科一新记录种(软体动物门,腹足纲,新腹足目)

在对中国科学院南海海洋生物标本馆馆藏芋螺科Conidae标本,以及近年来在南海补充采集的标本进行整理的过程中,通过形态分类学方法鉴定发现隶属于芋螺属Conus的中国海新记录种1种:锈色芋螺Conus ferrugineus Hwass in Bruguière,1792,标本采自西沙群岛。文章描述了该种的外部形态,查明了其生活习性和地理分布特点,并与相似种犊纹芋螺Conus vitulinus Hwass in Bruguière, 1792进行了比较,通过壳口内面前沟部位的颜色可将两者区分开:锈色芋螺呈白色,而犊纹芋螺呈紫(褐)色;同时对这两个相似种的其他区别特征进行了总结。

蜑螺属Nerita几个混淆种的比较研究(腹足纲,珍珠蜑螺目,蜑螺科)

蜑螺科Neritidae蜑螺属Nerita的一些种类形态近似,形态鉴定上存在种类混淆、同物异名或错误鉴定等现象。作者在整理中国科学院南海海洋生物标本馆和中国科学院海洋生物标本馆历年来采集的蜑螺科标本时,对4种隶属于蜑螺属的易混淆种进行了比较研究。通过对标本的反复对比,分别找出了它们之间外部形态、地理分布以及生活习性方面的差异,澄清了混淆,确立了其分类地位:1)矮狮蜑螺Nerita chamaeleon Linnaeus,1758和圆蜑螺Nerita histrio Linnaeus,1758两者贝壳形态相近,在我国海区分布重叠,存在混淆以及错误鉴定的现象,根据螺旋部以及壳面雕刻可将它们区分开,即前者壳面螺肋光滑,后者螺肋粗糙,而前者螺旋部较后者高;2)锦蜑螺Nerita polita Linnaeus,1758和杂色蜑螺Nerita litterata Gmelin,1791两个种常被混淆在一起,都鉴定为锦蜑螺,前者在我国见于台湾、海南岛和西沙群岛,后者在我国见于台湾、福建、广东、广西和西沙群岛,其中杂色蜑螺此前在我国仅见于台湾,本文的报道进一步完善了该种的地理分布信息。

中国海塔螺科Turridae一新记录种(软体动物门,腹足纲,新腹足目)

在整理分类中国科学院南海海洋生物标本馆馆藏的塔螺科标本时,鉴定出隶属于厚重螺属Crassispira的一中国海新记录种:蟹守厚重螺Crassispira cerithina(Anton,1838)。文中对该种的贝壳形态进行了详细描述,并对其分类地位以及主要鉴别特征进行了讨论。

Influence of mesoscale eddies on primary production in the South China Sea during spring inter-monsoon period

Mesoscale eddies have been suggested to have an impact on biological carbon fixation in the South China Sea （SCS）. However, their overall contribution to primary production during the spring inter-monsoon pe riod is still unknown. Based on large-scale biological and environmental in situ observations and synchro nous remote sensing data, the distribution patterns of phytoplankton biomass and the primary production, and the role of mesoscale eddies in regulating primary production in different eddy-controlled waters were investigated. The results suggested that the surface chlorophyll a concentrations and water column inte grated primary production （IPP） are significantly higher in cyclonic eddies and lower in the anticyclonic eddies as compared to that in non-eddy waters. Although eddies could affect various environmental factors, such as nutrients, temperature and light availability, nutrient supply is suggested to be the most important one through which mesoscale eddies regulated the distribution patterns of phytoplankton biomass and pri mary production. The estimated IPP in cyclonic and anticyclonic eddies are about 29.5% higher and 16.6% lower than the total average in the whole study area, respectively, indicating that the promotion effect of mesoscale cold eddies on the primary production was much stronger than the inhibition effect of the warm eddies per unit area. Overall, mesoscale eddies are crucial physical processes that affect the biological car bon fixation and the distribution pattern of primary production in the SCS open sea, especially during the spring inter-monsoon period.

Striking taxonomic differences in summer zooplankton in the northern South China Sea: implication of an extreme cold anomaly

An extreme persistent cold anomaly was prevailing in the South China Sea in February 2008. In order to understand the effect of the cold anomaly on zooplankton community, the zooplankton composition, abundance and biomass were analyzed in the northern South China Sea in August 2007 and August 2008. A total of 467 zooplankton species representing 16 groups were identified, with 275 species in August 2007 and 351 in August2008. Copepods were the most dominant zooplankton group in the study area. Compared with 2007, a dramatic decline was observed in the abundance of four dominant copepod species： Subeucalanus subcrassus, Temora discaudata, Nannocalanus minor and Temora turbinata in 2008. Moreover, zooplankton abundance declined from 133.37 ind./m^3 in August 2007 to 75.49 ind./m^3 in August 2008. In contrast, the abundance of medusa, such as Diphyes chamissonis, and tunicate, such as Doliolum denticulatum and Dolioletta gegenbauri, increased during the same season. Cluster analysis showed that there was a difference in zooplankton community structure between the two years. These variations in zooplankton communities were indicative of an anomalous oceanographic condition along with the extreme cold event in 2008.

A new species of Cymbasoma Thompson, 1888(Copepoda: Monstrilloida) from the Fujian coast, China

A new monstrilloid copepod species, Cymbasoma cheni sp. nov., from Meizhou Bay (an embayment in Fujian Province, southeastern China) is described and illustrated. The diagnostic character of the new species is the structure and armature of the fi fth leg, which is represented by a single lobe armed with three naked setae subequal in length. The new species closely resembles Cymbasoma bowmani Suárez- Morales and Gasca, 1998 in the structure of the fi fth legs, and the body proportions, including total body length, and relative lengths of the cephalothorax and the genital double somite. However, Cymbasoma cheni sp. nov. is distinguished by lack of cuticular ornamentation on the cephalothorax, the position of the oral papilla, and the structure of the fi fth leg with three naked setae. Although the structure of the fi fth legs is similar in Cymbasoma cheni sp. nov. and Cymbasoma quintanarooense (Suárez-Morales, 1994), the new species can be easily distinguished from Cymbasoma quintanarooense by the relative length of the antennule, diff erences in the genital double-somite and the ovigerous spines, and the shape of ocelli. This is the sixth record of this genus from China seas.

Planaxidae(Mollusca, Gastropoda) from the South China Sea

Abstract Planaxidae is a family of tropical and subtropical marine gastropods that are adapted to an intertidal, rocky environment. The present study deals with three species in the family Planaxidae from the South China Sea： Planaxis sulcatus （von Born, 1778）, Angiola longispira （Smith, 1872）, and Supplanaxis niger （Quoy and Gaimard, 1833）, based on specimens deposited in the Marine Biodiversity Collections of the South China Sea, Chinese Academy of Sciences. The taxonomic status, main morphological characteristics of the shell and radula, distribution, and habitat of these three planaxid species are presented. We also briefly discuss their morphological differences and the biogeographic distribution.