We studied on microzooplankton (MZP) communities from two major rivers, the Mandovi and the Zuari estuarine system of Goa on central west coast India. Despite both estuaries having a common point of discharge (eastern part of the Arabian Sea) and origin (in the Western Ghats), the Zuari estuary retains its marine condition; in contrast, the Mandovi estuary becomes a nearly freshwater condition for most parts of the year. The essential components of the marine food web, the MZP showed substantial seasonal variation driven by hydrographical parameters. Canonical correspondence analysis (CCA) depicts that prevailing differential environmental variables such as salinity, chlorophyll a, and dissolved oxygen influence the MZP assemblages in the tropical estuarine systems, which lead to the dominance of heterotrophic dinoflagellates (~80%) in the Zuari estuary for most parts of the year and dominance of loricate ciliates (~67%) in the Mandovi estuary. During monsoon, the seasonal intrusion of low oxygen water from the coastal region directs the dominance of heterotrophic dinoflagellates (22 to 80%) in these estuarine systems, particularly in the Zuari estuary. Whereas, prevailing high saline waters during the pre-monsoon (23 to 62%) and the post-monsoon (34 to 55%) supported the loricate ciliates dominated MZP community. The higher abundance of MZP in the upstream during the pre-monsoon and euhaline region of the downstream compared to the upstream (oligohaline) during monsoon and post-monsoon seems to be supported by microbial food (pico and nano-plankton), which warrants further investigation.

我们研究了印度中西海岸果阿的两条主要河流曼多维河和祖阿里河口河系的微浮游动物（MZP）群落。尽管两个河口都有一个共同的排放点（阿拉伯海的东部）和起源（在西高止山脉），但祖阿里河口仍保持其海洋状况。相比之下，曼多维河河口在一年中的大部分时间都变成了近乎淡水的状态。MZP是海洋食物网的重要组成部分，受水文参数驱动显示出明显的季节性变化。典型对应分析（CCA）描述了主要的差异环境变量，例如盐度，叶绿素a以及溶解氧影响热带河口系统中的MZP组合，这导致一年中大部分时间在Zuari河口占优势的异鞭毛藻（〜80％）和在Mandovi占优势的纤毛虫（〜67％）河口。在季风期间，沿海地区低氧水的季节性入侵导致这些河口系统中，特别是在祖里河口中，异养鞭毛藻的占主导地位（占22％至80％）。季风前（季风后）和季风后（34％至55％）盛行的高盐度水支持了以网状纤毛虫为主的MZP群落。