<i>Cladophora</i> spp. (Chlorophyta) modulate environment and create a habitat for microalgae in hypersaline waters

<i>Cladophora</i> spp. constantly or periodically form floating and benthic mats in Crimean hypersaline lakes and lagoons. In 2017–2018, characteristics of the <i>Cladophora</i> mats and the microalgae on <i>Cladophora</i> filaments were studied employing field research and microscopy. The whole <i>Cladophora</i> mat has a vertical structure, including the upper and lower layers of the floating mat and benthic mat. In total, 50 species of microalgae were found: 40 of them belonged to Bacillariophyta (Bacillariophyceae and Mediophyceae), two to Haptophyta (Coccolithophyceae), four to Miozoa (Dinophyceae), one to Chlorophyta (Zygnematophyceae) and three to Cyanobacteria (Cyanophyceae). Floating layers of the mat differed significantly in species composition from the benthic mat. The total abundance of microalgae and their biomass on <i>Cladophora</i> (per unit area of filaments) varied widely within sampling sites from 3.79 × 10⁶ to 5.04 × 10⁸ cells m^–2 and 2.6 to 2197.8 mg m^–2. The total mass of microalgae achieved more than 32% of the mass of <i>Cladophora</i>, averaging 7.7% (standard deviation = 13.3).

刚毛藻属（Cladophora）物种在克里米亚高盐湖泊与潟湖中持续或周期性形成漂浮型与底栖型藻垫。2017—2018年，本研究采用野外调查与显微镜观测技术，对刚毛藻藻垫以及刚毛藻丝体上附生微藻的特征展开研究。完整的刚毛藻藻垫具有垂直分层结构，涵盖漂浮藻垫的上层、下层以及底栖藻垫。本次研究共检出50种微藻：其中40种隶属于硅藻门（Bacillariophyta），包含硅藻纲（Bacillariophyceae）与中硅藻纲（Mediophyceae）；2种隶属于定鞭藻门（Haptophyta），颗石藻纲（Coccolithophyceae）；4种隶属于Miozoa，涵盖甲藻纲（Dinophyceae）；1种隶属于绿藻门（Chlorophyta），双星藻纲（Zygnematophyceae）；3种隶属于蓝细菌门（Cyanobacteria），蓝藻纲（Cyanophyceae）。漂浮藻垫层与底栖藻垫层的物种组成存在显著差异。在各采样点内，刚毛藻丝体上附生微藻的总丰度与生物量（以丝体单位面积计）波动范围极大，丰度介于3.79×10⁶ 至 5.04×10⁸ 细胞·米⁻²之间，生物量介于2.6 至 2197.8 毫克·米⁻²之间。微藻总生物量可达刚毛藻生物量的32%以上，平均占比为7.7%（标准差=13.3）。