Comparative Microbiota Composition Across Developmental Stages of Natural and Laboratory-Reared Chironomus circumdatus Populations From India

Sivan Laviad-Shitrit; Rotem Sela; Yehonatan Sharaby; Leena Thorat; Bimalendu B Nath; Malka Halpern

doi:10.3389/fmicb.2021.746830

Comparative Microbiota Composition Across Developmental Stages of Natural and Laboratory-Reared Chironomus circumdatus Populations From India

Front Microbiol. 2021 Nov 26:12:746830. doi: 10.3389/fmicb.2021.746830. eCollection 2021.

Authors

Sivan Laviad-Shitrit¹, Rotem Sela¹, Yehonatan Sharaby¹, Leena Thorat^{2

3}, Bimalendu B Nath², Malka Halpern^{1

4}

Affiliations

¹ Department of Evolutionary and Environmental Biology, University of Haifa, Haifa, Israel.
² Department of Zoology, Savitribai Phule Pune University, Pune, India.
³ Department of Biology, York University, Toronto, ON, Canada.
⁴ Department of Biology and Environment, University of Haifa, Haifa, Israel.

Abstract

Chironomids are aquatic insects that undergo a complete metamorphosis of four life stages. Here we studied, for the first time, the microbiota composition of Chironomus circumdatus, a tropical midge species, both from the Mula and Mutha Rivers in Pune, India and as a laboratory-reared culture. We generated a comparative microbial profile of the eggs, larvae and pupae, the three aquatic life stages of C. circumdatus. Non-metric multidimensional scaling analysis (NMDS) demonstrated that the developmental stage had a more prominent effect on the microbiota composition compared to the sampling location. Notably, the microbiota composition of the egg masses from the different sampling points clustered together and differed from laboratory culture larvae. Proteobacteria was the dominant phylum in all the environmental and laboratory-reared egg masses and pupal samples, and in the laboratory-reared larvae, while Fusobacteria was the dominant phylum in the larvae collected from the field environment. The most abundant genera were Cetobacterium, Aeromonas, Dysgonomonas, Vibrio, and Flavobacterium. The ten amplicon sequence variants (ASVs) that most significantly contributed to differences in microbiota composition between the three sampled locations were: Burkholderiaceae (ASVs 04 and 37), C39 (Rhodocyclaceae, ASV 14), Vibrio (ASV 07), Arcobacter (ASV 21), Sphaerotilus (ASV 22), Bacteroidia (ASVs 12 and 28), Flavobacterium (ASV 29), and Gottschalkia (ASV 10). No significant differences were found in the microbial richness (Chao1) or diversity (Shannon H') of the three sampled locations. In contrast, significant differences were found between the microbial richness of the three life stages. Studying the microbiota of this Chironomus species may contribute to a better understanding of the association of C. circumdatus and its microbial inhabitants.

Keywords: Cetobacterium; Chironomus circumdatus; bacterial composition; chironomids; developmental stages; microbiota.