Abstract:
Objective This study aimed to discuss the effects of polyculture with
Pelteobagrus fulvidraco on the growth performance， nutritional quality， intestinal microbiota and aquaculture micro-ecological environment of
Micropterus salmoides， so as to identify the appropriate polyculture ratio， thereby providing a scientific basis for the ecofriendly and healthy culture of
Micropterus salmoides.
Method Experimental groups were
Micropterus salmoides monoculture group （Group C）， low-density polyculture group （
Micropterus salmoides∶
Pelteobagrus fulvidraco=4∶1， Group L）， middle-density polyculture group （
Micropterus salmoides∶
Pelteobagrus fulvidraco=2∶1， Group M）， and high-density polyculture group （
Micropterus salmoides：
Pelteobagrus fulvidraco=1∶1， Group H）. After 60 days of feeding， the growth performance， muscle nutritional quality， intestinal microbiota of
Micropterus salmoides，
and characteristics of microbial community in aquaculture water were determined.
Result In Group M， the specific growth rate （1.69 %/d） and the condition factor （1.52） of
Micropterus salmoides were the highest， but the feed coefficient （1.08） was the lowest. The crude protein content in
Micropterus salmoides muscle of Groups M and Group H was significantly higher than that of the Group C （
P<0.05， the same below）. The contents of essential amino acids and umami amino acids in
Micropterus salmoides muscle in the Group M were significantly higher than those in the Group C. The muscle hardness and tackiness of
Micropterus salmoides in the Group M were significantly higher than those in the Group C， but the contents of earthy odor substances （geosmin and 2-methylisoborneol） was significantly lower than that in the Group C. Polyculture with
Pelteobagrus fulvidrac had an obvious impact on the intestinal microbial community structure of
Micropterus salmoides. Compared with
Micropterus salmoides in the Group C， the relative abundances of Bacillota and Pseudomonadota in the intestine of
Micropterus salmoides in the Group M were significantly increased， whereas the relative abundance of Actinomycetota was significantly decreased. The relative abundance of
Sphingomonas increased significantly as the
Pelteobagrus fulvidraco density increased， and it had a significantly positive correlation with the muscle crude protein content. Moreover， polyculture with
Pelteobagrus fulvidraco led to marked changes in the structure of microbial community in aquaculture water for
Micropterus salmoides： The relative abundances of
Massilia and
Exiguobacterium in the Group M were significantly higher than those in the Group C； the relative abundance of
Exiguobacterium had a highly significant positive correlation with Chlorophyta density in the water bodies （
P<0.01） and a significant correlation with the relative abundance of
Sphingomonas in the intestinal microbiota of
Micropterus salmoides.
Conclusion The polyculture of
Micropterus salmoides and
Pelteobagrus fulvidraco with ratio of 2∶1 could reshape the aquaculture ecology， therefore， it can significantly improve the growth performance and muscle nutritional quality， and optimize the structure of intestinal microbiota and aquatic microbial community for
Micropterus salmoides， thus achieving a synergistic improvement in growth， quality and environment， making it an ideal ecological aquaculture model.
下载: