Page 205 - 《水产学报》2025年第11期

葛恒，等 水产学报, 2025, 49(11): 119616

was randomly selected and treated with 4 different flow (0, 2.5, 4.5 and 6.5 bl/s) for 6 weeks. Their growth performance, intest-
inal oxidative stress and digestive function were tested to elucidate the effects of flow rate on M. salmoides juveniles. The
present results showed that the 2.5 bl/s increased the growth rate and decreased the mortality rate of juvenile M. salmoides
(P<0.05). Meanwhile, 2.5-6.5 bl/s led to the significant increases of intestinal MDA concentration, and decreases of SOD activ-
ity. However, the flow rate caused the different degree of increase of CAT and GPX activity from 24 h to 48 h, and then the sig-
nificant decrease were observed after 96-hour treatment (P<0.05). These results indicated that the intestinal oxidative stress of
M. salmoides juveniles was induced by 96-hour flow treatments, and CAT and GPX activities play an important role in
response to oxidative damage induced by acute flow treatment in intestine of M. salmoides. Additionally, 2.5-6.5 bl/s flow led
to a significant increases of trypsin activities, and 6.5 bl/s flow significantly down-regulated the activities of amylase and lipase
after two-week flow treatment. Thus, different flow increased the intestinal digestion and absorption of amino acids, but the
higher flow rate inhibited the growth through decreasing the activities of amylase and lipase. Analysis of intestinal transcrip-
tome sequencing suggested that 48-hour treatment of 2.5 bl/s flow resulted in the most differential genes (DEGs) enriching in
the pathways mainly related to neuroactive ligand-receptor interactions and amino acid metabolism, and the DEGs were signi-
ficantly enriched in the signaling pathways related to amino acid and fatty acid metabolism in the 4.5 and 6.5 bl/s groups, indic-
ating that the short-term flow treatment enhanced the intestinal metabolism of fatty acids and amino acids. Under 6-week flow
treatment, DEGs were enriched in the signaling pathways related to nucleotide, amino acid and lipid metabolism in the 4.5 and
6.5 bl/s groups, indicating that M. salmoides juveniles still need to increase lipid metabolism to adapt to the energy consump-
tion induced by higher flow treatment, in which PPAR and FoxO signaling pathways played important roles. In summary, the
flow rate of 2.5 bl/s was the optimal flow rate for the growth and development of larval M. salmoides juvenile during the early
development. In addition, there was a time-dependent effect of flow that short-term flow treatment inhibited and long-term flow
treatment promoted the growth performance. Therefore, stress damage induced by short-term flow changes should be avoided
during the seedling cultivation of M. salmoides. Instead, long-term application of an appropriate flow rate should be selected to
improve growth performance and health.
Key words: Micropterus salmoides; flow rate; growth and development; intestinal; transcriptome
Corresponding authors: CHAI Yi. E-mail: chaiyi123456@126.com;
LIANG Hongwei. E-mail: lianghw@yfi.ac.cn
Funding projects: Key Research and Development Program of Hubei Province (2023BBB122); Central Public-Interest Sci-
entific Institution Basal Research Fund, CAFS (2023TD36); National Freshwater Aquatic Germplasm Resource Center
(FGRC18537)

https://www.china-fishery.cn 中国水产学会主办 sponsored by China Society of Fisheries
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