COMMUNITY STRUCTURE AND INFECTION OF GASTROINTESTINAL HELMINTHS IN GLYPTOSTERNUM MACULATUM FROM TIBET AUTONOMOUS REGION, CHINA

Glyptosternum maculatum is the only fish belong to Glyptosternum in China, and it is the fish that only lives in the Yarlung Zangbo River in Tibet Autonomous Region. In order to understand the community structure of gastrointestinal helminths and infection of G. maculatum, the endemic fish of Tibet Autonomous Region, 383 individuals of the species were dissected from May 2019 to August 2019. Seven species of gastrointestinal helminths were found of G. maculatum, including Bathybothrium sp., Proteocephalus sp., Allocreadium sp., Neoechinorhynchus sp., Echinorhynchus gymnocyprii, Contracaecum eudyptulae and Rhabdochona sp.. Most of them were widespread parasites. The population of G. maculatum were divided into whole group, different sex groups and different total-length groups. The gastrointestinal helminths’ community diversity, dominant species and infection of G. maculatum with different groups were respectively analyzed. The results were as follows: in the whole group of G. maculatum, the Shannon-Wiener index and the Berger-Parker index of the gastrointestinal helminths were 1.53 and 0.37 respectively, and the dominant species was C. eudyptulae, which had the highest infection quantity, infection rate, infection intensity and average abundance. In the different sex group, the Shannon-Wiener index was 0.2—1.57, the Berger-Parker index was 0.34—0.93, the dominant species was Contracaecum sp. in all sex groups, and the Neoechinorhynchus sp. was the dominant species in the female group. The infection rate and mean abundance of C. eudyptulae and Neoechinorhynchus sp. were high. In the different total-length group, the Shannon-Wiener index was 0.22—1.59, the Berger-Parker index was 0.34—0.94, the dominant species was C. eudyptulae or Neoechinorhynchus sp. The infection rate and mean abundances with both helminths were high. It can be concluded that the dominant species in the gastrointestinal helminths of native fishes in Tibet Autonomous Region were mainly nematodes, and most of them were heteroparasites. Fish were only their intermediate hosts, and birds play an important role in their transmission. This study was to understand the community structure and infection of gastrointestinal helminths of G. maculatums, to further clarify the species composition and parasitic characteristics of the parasites in Tibetan fishes, and to provide basic data for studying the environmental adaptability of endohelminths and the coevolution with the host.