Biological Oceanography Division, CSIR-National Institute of Oceanography, Dona Paula, Goa, 403 004, India.
Present Address: Centre for Marine Living Resources and Ecology, Ministry of Earth Sciences, Kochi, India.
Environ Monit Assess. 2023 Jul 14;195(8):948. doi: 10.1007/s10661-023-11568-0.
We studied the community composition of microzooplankton (MZP) from the surface waters off Candolim, Goa. The MZP communities were examined for the year 2013, covering different seasons and four stations (Near-shore: G3 & G4, offshore: G5 & G6). A total of 30 species belonging to 24 genera were recorded, which include loricate ciliates (LC: 14 species of 13 genera), aloricate ciliates (ALC: 5 species of 3 genera), heterotrophic dinoflagellates (HDS: 11 species of 8 genera), and copepod nauplii. The MZP abundance in the coastal waters varied spatially irrespective of different seasons, with higher abundance in the offshore stations (G5 & G6, 38-127 cells L-1) and lower abundance in the near-shore stations (G3 & G4, 20-97 cells L-1). The MZP community composition showed the dominance of HDS (16-85%) in the near-shore stations during most of the seasons and inferiority during NEM (16-18%). Moreover, all the coastal waters (near and offshore) were dominated by HDS (58-85%) during spring inter-monsoon. The dominant species of HDS were Dinophysis apicata, Dinophysis caudata, Prorocentrum micans, Protoperidinium breve, Protoperidinium latistriatum, and Protoperidinium granii. The statistical analysis (Canonical correspondence analysis and Spearman's rank correlation) depicts that the MZP abundance and community composition were mainly controlled by salinity (r = 0.4-0.7). Whereas the dominance of HDS in the coastal waters could be the reason for its mixotrophic nature and diverse feeding mechanism. Thus, a strong positive correlation between the HDS and LC (r = 0.73-0.92) showed the feeding ability of HDS in their relative community.
我们研究了果阿坎多利姆（Candolim）外海的表层微型浮游动物（MZP）群落组成。 2013 年，我们对不同季节和四个站位（近岸：G3 和 G4，离岸：G5 和 G6）的 MZP 群落进行了检查。共记录了 30 个物种，隶属于 24 属，包括有鞘纤毛虫（LC：13 属 14 种）、无鞘纤毛虫（ALC：3 属 5 种）、异养鞭毛藻（HDS：8 属 11 种）和桡足类无节幼体。 沿海海域的 MZP 丰度在不同季节之间存在空间差异，离岸站位（G5 和 G6）的丰度较高（38-127 细胞 L-1），近岸站位（G3 和 G4）的丰度较低（20-97 细胞 L-1）。 MZP 群落组成在大多数季节中表现出近岸站位 HDS（16-85％）的优势，而在东北季风期间则处于劣势（16-18％）。此外，所有沿海海域（近岸和离岸）在春季季风间歇期均以 HDS（58-85％）为主导。 HDS 的优势种为 Apicata 属的夜光藻、尾丝藻属的尾丝藻、微小原甲藻、短角藻属的短角藻、宽角藻属的长角藻和颗粒原甲藻。统计分析（典范对应分析和 Spearman 秩相关）表明，MZP 丰度和群落组成主要受盐度控制（r = 0.4-0.7）。而沿海海域中 HDS 的优势可能是其混合营养特性和多种摄食机制的原因。因此，HDS 与 LC 之间存在很强的正相关（r = 0.73-0.92），表明 HDS 在其相对群落中的摄食能力。
