中国团藻科新记录属——板藻属(Platydorina)

在广东省深圳水库采集的浮游植物样品中发现团藻科1个单种属及其种:板藻属(Platydorina)、具尾板藻(Platydorina caudata Kofoid)。植物体扁平状马蹄形,微呈左旋;在马蹄形后端具3至5个胶质突起;由16或32个细胞在胶质基质中朝不同的方向排列成单层的群体,细胞球形或梨形,具2条等长鞭毛,细胞在群体两面交错排列;每个细胞具1个眼点;鞭毛基部具2个伸缩泡;色素体大型杯状,1个蛋白核位于杯状色素体的基部。无性繁殖通过亲体部分或全部细胞的反复分裂完成;有性生殖为异配生殖,形成厚壁休眠合子。

Platydorina Kofoid,A Newly Recorded Genus of Volvocaceae from China

Platydorina is a monotypic genus consisting of P.caudata Kofoid found in phyto-plankton samples collected from Shenzhen Reservoir of Guangdong province.The colonies were flattened,slightly twisted in the left sinistral,and horseshoe-shaped with three to five posterior projections in a gelatinous matrix.Each colony contained sixteen or thirty-two cells,a stigma,two contractile vacuoles at the base flagella,and a massive cup-shaped chloroplast with a single basal pyrenoid.Cells were spherical or pear-shaped,arranged in one layer,and oriented in different directions in the gelatinous matrix.Asexual reproduction was accomplished by the repeated division of gonadal cells in the whole or part of the parent colony directly.Sexual reproduction was anisogamous with sperm packets,forming walled hypnozygotes.