Study of the characteristics of intestinal bacteria of little yellow croaker (Larimichthys polyactis) and big head croaker (Collichthys lucidus) from the Lyusi fishing ground

ABSTRACT

Little yellow croaker (Larimichthys polyactis) and big head croaker (Collichthys lucidus) are economically important fishes of the Lyusi fishing ground. The intestinal bacterial communities of L. polyactis and C. lucidus were examined using 16S rRNA high-throughput sequencing technology. The Shannon and Chao-1 indices of the small body length group were significantly larger than those of the large body length group, and the Simpson index was the opposite (P < 0.05). Pseudomonas and Photobacterium of L. polyactis were significantly less abundant than those of C. lucidus (P < 0.05), and Clostridium sensu stricto and Acinetobacter were significantly more abundant than those of C. lucidus (P < 0.05). The abundance of Pseudomonas in L. polyactis increased significantly with increasing body length (P < 0.05), and the abundances of Psychrobacter and Acinetobacter decreased significantly with increasing body length (P < 0.05). The abundance of Clostridium sensu stricto in the large body length group was significantly increased compared with that in the small body length group (P < 0.05). The abundance of Vibrio first increased significantly and then decreased significantly (P < 0.05) with increasing body length. The abundances of Pseudomonas and Photobacterium of C. lucidus increased significantly with increasing body length (P < 0.05). The abundance of Psychrobacter in the large body length group was significantly lower than that in the other groups (P < 0.05). Clostridium sensu stricto was significantly more abundant in the small body length group than in the other groups (P < 0.05). Vibrio was significantly more abundant in the small body length group than in the other groups (P < 0.05). Studies have shown that the feeding range of L. polyactis is wider than that of C. lucidus. Compared with C. lucidus, L. polyactis is less carnivorous and more herbivorous. The carnivorous habit of the two fish became more and more obvious with the increase of body length. The Clostridium sensu stricto related to herbivory of the two fishes may be related to the need to degrade indirectly ingested plants. The larval stages of the two fishes had a higher proportion of Vibrio.

KEYWORDS:

• Larimichthys polyactis
• Collichthys lucidus
• intestinal bacteria
• 16S rRNA
• feeding habits

Acknowledgements

This work was supported by the National Marine Ranching Demonstration Project (D8005-18-0188) and the Natural Science Foundation of Jiangsu (BK20170438). We thank the editor and the anonymous reviewers for the useful comments, which have helped us to improve the final manuscript.

Author contributions

Mr Shixuan Chen was involved in the design and operation of the sampling and experiment, wrote the first draft and led subsequent revisions and editing of the manuscript. Professor Shuo Zhang was involved in conducting data analysis. Researcher Wenwen Yu was involved in processing the data analysis. Mr Hao Xu was involved in experimental operation.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

All raw sequences files can be found on NCBI using the BioProject ID PRJNA810591.

Compliance with ethical standards

Conflict of interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Ethical approval All experimental protocols in this study were approved by the Ethics Committee for Animal Experiments of Shanghai Ocean University. The methods used in this study were conducted in accordance with Laboratory Animal Management Principles of China.

Additional information

Funding

This work was supported by the Jiangsu Haizhou Bay National Sea Ranching Demonstration Project (D-8005-18-0188) and the Natural Science Foundation of Jiangsu Province (BK20170438).