Abstract：
Potholes are microhabitats in riverine ecosystems that substantially contribute to the unique regional faunal diversity and community composition. Investigations on the ecological status of potholes in riverine habitats are very scanty. The present work is of utmost importance, particularly as a pioneering study to evaluate the health status of riverine potholes using aquatic insects as potential biological indicators. Samples of water and aquatic insects were collected and analyzed during the pre-monsoon season from February 2022 to May 2022 in the potholes at Athirappilly and the Ezhattumugham regions of the Chalakudy river basin. The present study identified 208 individuals represented by 15 families in the potholes at Athirappilly, whereas 94 individuals belong to 10 families at Ezhattumugham. The computation of water quality parameters and benthic metrics revealed a significant variation between the stations. Spearman correlation analysis revealed that the water temperature, electrical conductivity, dissolved oxygen concentration, and biochemical oxygen demand were influencing the distribution of aquatic insects in the potholes. Families such as Perlidae, Ephemeridae, Baetidae, Stenopsychidae, and Hydropsychidae (sensitive families) reported from the well-oxygenated potholes at Athirappilly, where the water temperature and biochemical oxygen demand were minimum. The significantly high percentage composition of Ephemeroptera, Plecoptera, and Trichoptera taxa and a low family biotic index value indicate good health condition of the potholes at Athirappilly. In contrast, the low percentage composition of Ephemeroptera, Plecoptera, and Trichoptera taxa and high family biotic index values, with the abundance of tolerant families (Micronectidae, Caenidae, and Chironomidae), reflect the impact of organic pollution at Ezhattumugham.
摘要：
坑洞是河流生态系统中的微生境，极大地促进了独特的区域动物多样性和群落组成。对河流栖息地坑洼的生态状况的调查很少。目前的工作至关重要，特别是作为一项开创性的研究，以水生昆虫作为潜在的生物学指标来评估河流坑洼的健康状况。在2022年2月至2022年5月的季风前季节，在Chalakudy河流域的Athirappilly和Ezhattumugham地区的坑洼中收集并分析了水和水生昆虫的样品。本研究确定了Apthirappilly坑洼中15个家庭代表的208个人，而94个人属于Ezhattumugham的10个家庭。水质参数和底栖指标的计算表明，站点之间存在显着差异。斯皮尔曼相关分析表明,水温,电导率，溶解氧浓度,生化需氧量影响水生昆虫在坑洼中的分布。像Perlidae这样的家庭，大象科,Baetidae,Stenopsychidae，和Hydropsyidae（敏感家庭）从Athirappilly的充氧坑洼中报告，水温和生化需氧量最低。星翅目的百分比组成非常高，Plecoptera,毛翅目分类群和较低的家庭生物指数值表明Athirappilly坑洼的健康状况良好。相比之下,星翅目的低百分比组成，Plecoptera,和毛翅目类群和高家庭生物指数值，随着宽容的家庭的丰富(微科，Caenidae,和摇蚊科)，反映了有机污染对Ezhattumugham的影响。
