【作者】 王金宝；

【导师】 李新正； 谭智源；

【作者基本信息】 中国科学院研究生院（海洋研究所） ， 海洋生物学， 2003， 硕士

【摘要】 放射虫是一类大洋性浮游原生动物，广泛分布于从赤道到两极的各种海域，同时垂直分布于从海洋表层到几千米的深层水体中。放射虫也是海洋微体古生物中的一个重要类群，沉积物中的化石放射虫蕴涵大量的古环境和古气候信息，在古海洋学研究中有重要作用。分类学和生态学研究是各项应用研究的基础。本研究对南海北部浮游生物中的放射虫种类进行了系统鉴定和定量统计，研究了放射虫的种类组成与类群特征及其丰度和种类多样性，初步分析了环境因子对放射虫数量分布的影响。 一.分类学研究结果如下：㈠. 调查区内采集的标本经分析鉴定共计2目 41 科134属240种，其中4个新种，18个未定种和71个新记录。文中提供各种的异名录、形态图、地理分布对部分新记录的种类和新种进行了描述, 并对各分类阶元编制了检索表。新种描述如下：1) 棘帽虫 (新种) Theopilium paliurum sp.nov. 壳呈扁平圆锥状，表面光滑，具浅的领缢。3节壳宽度之比为1:6:1.5, 头呈亚球形，自头部中生出7条头棘，各棘均为角锥状，是头长的3－5倍。胸壁上具三条不明显的肋，网孔呈规则六角形，网孔逐渐向周围变大。腹部无肋、扁平，有3－4圈排列规则、较小的、不规则的方形孔。本种与帽虫属的其它种不同之处在于有7条较长的角锥状头棘，网孔六角形且逐渐变大。2) 纤细格盔虫（新种） Clathrocorys gracilis sp. nov. 头呈豆形，具由瘦细的桁条纵横相交编织状方形孔；头的基部中央生出四条棱柱状的放射梁，梁的大小几近相等，其中一条向上垂直生出形成头角，其余三条向下生出，成为分散的足；各足近心端（靠近头部处）有分枝桁条构成的杯状结构。三个子午面（介于头角与足之间），有少数较粗的分枝生出，与由小枝构成的垂直翼相连；各翼中间有一个大网孔，两个中孔和两个小孔，边缘有3-5排平行排列蛛网状的方形小孔。扁平角锥形胸部下方也有<WP=4>由足部分枝连成的大孔，孔形与翼网孔近似。蛛网状的瘦细桁条充满各大孔。本种与墨氏格盔虫(Haeckel, 1887, p.1219, pl.64, fig.8.)相似，但翼孔的排列形式和头部格孔有区别，后者翼的中间为小孔，然后才是大孔；另外头部孔为不规则方形孔，各足近心端无杯状桁条结构。又本种与陶氏格盔虫(Haeckel, 1887, p.1220, pl.64, fig.10.)相似，但后者的头基部有7 条放射梁。3) 喙锥帽虫(新种) Artopilium rostrum sp. nov　　壳呈梭形，长为宽的2倍。壳具一领缢和4个内环膈，有1胸节和4腹节。头部呈亚球形，头内有内骨骼4根，各内骨骼相联汇于头腔内，其中1根穿出头顶成为头棘，头棘斜生、棱锥状，其余3根于头部领缢沟处生出，成游离的翼，翼具小孔，翼与头棘约等长。胸部钟罩形，其长约为第一腹节的1.5倍。各腹节长不相等，第一、二节等长，第三、四腹节稍短; 腹部圆筒形口收窄。头部各小孔大小相若，胸腹两部开孔类圆形，外具六角形框架，规则排列.本种与梭锥帽虫Artopilium fusiforme (Tan et Tchang, 1976, p.293, textfig. 74.)相似，但后者只有三腹节且胸翼不明显。4) 亮美帽虫(新种) Lampromitra lucida sp.nov. 壳为扁平圆锥形，具浅的领缢，两节壳宽度之比为1:9, 头呈半球形，有一斜生的圆锥形的顶角，角长约为头直径的两倍，头部开孔为小的不规则的多边形，胸部具6-7排亚规则的六角形网孔，自领缢向外逐渐变大，排列规则。三条胸肋较短，仅到胸部的上部。口缘圆形，边缘有一轮规则的方形小孔和由非常短、分散的小杆形成的冠。 本种区别于本属其它种的特征在于本种具较短的肋及逐渐变大的六角形网孔。㈡. 该调查区的放射虫区系为中国近海区系的南海亚区系，它与东海放射虫区系同属太平洋浅水放射虫系。 二．生态研究结果为：1）泡沫虫目个体数量占放射虫个体总数的65 %，共149种，占放射虫总种数的62%；罩笼虫目个体数量占个体总数的35 %，有91种，占总种数的38 %。泡沫虫目的个数和种数均居优势。2）根据各个种在总个体数量中排序，占全部个体数量的2%以上者定为优势种，共计10种，它们是海绵球虫Spongosphaera streptacantha Haeckel，三臂星虫 Triastrum aurivillii Cleve，四房面包虫四房亚种 Ommatartus tetrathalamus tetrathalamus Haeckel，钟翼盔虫 Pterocorys campanula Haeckel，棒网虫 Dictyocoryne profunda Ehrenberg，美壳虫 Euchitonia furca Ehrenberg，锥网角虫 Dictyoceras virchowii Haeckel，星球虫<WP=5>Astrosphaera hexagonalis Haeckel，秀美壳虫 Euchitonia elegans Ehrenberg，四叶四门孔虫 Tetrapyle quadriloba Ehrenberg.此10种的个体数量占总个体数量的31.8％；占全部个体数量的1－2%者定为习见种，共12种；优势种和习见种占总数量的49.6%，其它218种为稀有种，占总量的50.4%。 3）调查区的放射虫在沿岸区域较少分布，但延向外海区域，其个体数量和种数随温、盐度的增加而增加，并受到南海暖流和季节性环流的影响。该调查区中放射虫含量最高为441个/米3，其种的多样性最高为47种。更多还原

【Abstract】 Radiolarians are a group of pelagic protozoa. occurring in tropical to polar regions and distributed in the surface waters of oceans to thousands of meters depth on the ocean bottom, as one of the dominant microfossil groups found in marine sediments, they are indicators of paleo-oceanographical environments and paleoclimatic variations. The present study which is based on material from collected surface waters of the northern South China Sea, treats of the taxonomy and ecology of the radiolarian fauna of this region and the relationships of radiolarians with their environmental factors. Ⅰ. Results of taxonomic study yielded a total of 240 species, belonging to 2 orders including 41 families and 134 genera. Four species are new to science, namely Theopilium paliurum, Clathrocorys gracilis, Artopilium rostrum, Lampromitra lucida. 1).Theopilium paliurum sp. nov.Shell flatly conical, smooth with slight collar stricture. Breadth of the three joints=1:6:1.5. Cephalis subspherical, seven pyramid apical horns arising from the centre of the cephalis, 3-5 times the length of the cephalis. Thorax with three ribs in its wall, and with subregular, hexagonal pores increasing in size towards the girdle. Abdomen flatter than the thorax, without ribs, nearly horizontal, with subregular, square pores, disposed in three to five concentric, circular series. This new species differs from other species of the genus in having 7 pyramid apical horns and in the hexagonal shape of the pores increasing in size towards the girdle.2). Clathrocorys gracilis sp. nov.Cephalis pear-shaped, with very thin thread-like bars interweaving irregularly square pores. Four strong, prismatic radial beams of nearly equal size arise from its<WP=157>base centre; beam vertical, straight and prolonged into cephalic horn; three descending radial beams prolonged into three large diverging feet; each foot with cup-shaped structure ramified bar in the proximal section (near cephalis). A few thick branches arise in three meridional planes (between the horn and each foot), interconnecting ramules form the three vertical latticed wings; each wing with a large mesh in the middle, a medium mesh and a small mesh on each side respectively, and three to five parallel arachnoidal rows of small, square, distal meshes. The three walls of the flat pyramidal thorax (between every two feet) are formed by structure similar to that of the wings; an arachnoidal wicker-work of very thin thread-like bars fills out the large meshes.This new species is close to Clathrocorys murrayi (Haeckel, 1887, p.1219, pl.64, fig.8.), but they are different in the arrangement of the wing meshes and in the shape of the cephalic pores, in the latter species, the wing has a small mesh in the middle, and large meshes and small meshes at the side, and has irregularly square cephalic pores, the feet of which do not have cup-shaped bars structure in the proximal section. This new species is similar to Clathrocorys teuscheri (Haeckel, 1887, p.1220, pl.64, fig.10.), but the latter has seven radial beams arising from the cephalic base centre.3). Artopilium rostrum sp. novShell fusiform, about 2 times as long as broad; has one collar stricture and three internal annular septa, one thoracic joint, and four abdominal joints; cephalis subspherical; in the cephalic cavity there are four inner skeletons which come together, one of which pierces through the cephalic wall to become an oblique apical horn, the rest arising from the collar stricture and prolonged into dissociative lattice-wings, the apical horn and three wings are of the same length. Thorax campanulate, 1.5 times as long as first abdominal joint. Abdominal joints unequal in length, the first and second joint equal in length, the other shorter. Mouth of abdomen cylindrical, constricted. Cephalis pores of nearly equal size; thorax and abdomen circular outside with hexagonal frame, regularly arranged.This new species is similar to Artopilium fusiforme (Tan et Tchang, 1976, p.293, textfig.74.), but the latter has thre更多还原