东印度洋赤道南北两侧春季活体浮游有孔虫的组成与分布

COMPOSITIONS AND DISTRIBUTION OF LIVING PLANKTONIC FORAMINIFERA IN SPRING WATERS ON THE EQUATORIAL TRANSECTION FROM THE EASTERN INDIAN OCEAN

2017年3月通过对在东印度洋海区6个站位53个垂直分层拖网浮游有孔虫样品进行的定量分析,探讨了该海区春季现代浮游有孔虫的组成、分布及其影响因素。东印度洋春季0～3 000m水层内共鉴定出17个浮游有孔虫属种,主要是Globigerinoides ruber,Globorotaloides hexagona,Globigerinoides sacculifer,Globigerinella aequilateralis,Neogloboquadrina dutertrei,Globorotalia menardii,Globiberinella calida,Pulleniatina obliquiloculata和Globorotalia theyeri等,它们是典型的热带亚热带暖水种浮游有孔虫群落。G.ruber,G.sacculifer最大丰度层在0～50m水层;G.conglomerata,G.hexagona最大丰度层均出现在50～100m;G.theyeris在100～1 000m间的水层均有活体出现,100～150m水层中该种浮游有孔虫丰度最高;G.scitula为深层水浮游有孔虫分子,主要出现于300～2 000m的深水水层。东印度洋春季浮游有孔虫群落的丰度在赤道中心区最低,由赤道向南北两侧扩展,其丰度逐渐递增的特点。浮游有孔虫丰度明显呈上层高,下层低的特点,在50～100m水层浮游有孔虫丰度最高,明显高于0～50m水层浮游的有孔虫丰度,这与印度洋50～100m水体中叶绿素最大值层相对应,表明浮游有孔虫受水体初级生产力影响明显。

Living planktonic foraminifera have been quantitatively analyzed on 53 plankton tow samples which were collected from 6sites in the eastern Indian Ocean in Spring,2017.The affecting factors on the distribution and compositions of foraminiferal faunal were discussed.A total of 17 planktonic foraminiferal species was identified from 0~3 000 mwater depths,mainly Globigerinoides ruber,Globorotaloides hexagona,Globigerinoides sacculifer,Globigerinella aequilateralis,Neogloboquadrina dutertrei,Globorotalia menardii,Globiberinella calida,Pulleniatina obliquiloculata and Globorotalia theyeri.The results indicate that most foraminifers occurred in the spring eastern Indian Ocean are tropical warm water species.G.ruberand G.sacculiferare mainly found in 0~50m.G.conglomerata,G.hexagonaappear mainly in 50~100m.G.theyeri s150 hows a wide depth range of 100~1 000 m,with an optimum around 100~150m.G.scitulais a kind of deep water planktonic foraminifera,which mainly appear in the deep water layer of 300~2 000 m.The foraminifera abundance in the equatorial sites is much less compare with others.In terms of vertical distribution,it has been shown that the abundance of planktonic foraminifera is obviously high in the upper layer and low in the lower layer.The foraminiferal maximum abundance layer is 50~100m waters,which is correspond to the subsurface chlorophyll maximum layer and shows that planktonic foraminifera is significantly affected by primary productivity.