Biodiv Sci ›› 2023, Vol. 31 ›› Issue (5): 22533.  DOI: 10.17520/biods.2022533

• Animal Diversity • Previous Articles     Next Articles

Diversity and community characteristics of free-living nematodes in plateau salt lakes in Nagqu City, Tibet

Helu Zhang1,2, Meihong Zhao1,2, Shichun Sun2,3, Xiaoshou Liu1,2,*()   

  1. 1. College of Marine Life Sciences, Ocean University of China, Qingdao, Shandong 266003
    2. Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, Shandong 266003
    3. College of Fisheries, Ocean University of China, Qingdao, Shandong 266003
  • Received:2022-09-18 Accepted:2022-11-28 Online:2023-05-20 Published:2023-05-23
  • Contact: * E-mail: liuxs@ouc.edu.cn

Abstract:

Aim: Being considered effective indicator species, free-living nematodes have great application potential in ecological monitoring. Therefore, the study of free-living nematodes in the Tibetan Plateau salt lakes may be of great importance to improve the benthic communities and ecological environment assessment systems for plateau salt lakes. The aim of this study is to assess diversity and community structure of free-living nematodes.
Methods: Quantitative investigations of free-living nematodes and their relationships with environmental factors were conducted by collecting sediment samples in 11 plateau salt lakes, including Kyêbxang Co, Dagze Co and Yibug Caka etc. in Nagqu City, Tibet, China, from July to August 2020.
Results: Total average abundance of free-living nematodes was 13.98 ± 22.21 ind./10 cm2. The abundance of free-living nematodes in euhalines (32.31-49.85) (19.33 ± 29.99 ind./10 cm2) was higher than those in oligohalines (0.64-4.70) (12.43 ± 4.18 ind./10 cm2) and mesohalines (10.20-11.82) (3.67 ± 0.73 ind./10 cm2). A total of 21 genera, belonging to 17 families, of free-living nematodes were identified, with Procephalobus, Trilobus, Miranema as the dominant genera, among which Procephalobus was the most abundant, accounting for 47.1% of the total free-living nematode that were identified. The dominant feeding type of free-living nematodes were algal feeders (59.7%), which was closely related to the abundance of primary producers and diatom abundance.
Conclusion: Differences in free-living nematode abundance and community structure in the plateau salt lakes in Tibet were mainly related to spatial variations in sediment organic matter content, bottom water salinity, and sediment water content. Salinity had no significant effects on the abundance of free-living nematodes. However, differences in community structure were positively correlated to salinity. In addition, the most abundant genera in the study lakes were different when compared to other lakes with high salinity. This could possibly be due to specific climatic characteristics, environmental stress, and human disturbance in the site and should be confirmed with further studies.

Key words: salt lakes, free-living nematode, diversity, community structure, Tibetan Plateau