Research
| Title： | Aeration causes lordosis in largemouth bass and blunt snout bream and identification of the associated genes |
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| First author： | Chen, Haijie; Peng, Leyang; Wang, Jing; Luo, Cheng; Qiao, Hui; Song, Guili; Lin, Shimei; Long, Yong |
| Journal： | AQUACULTURE |
| Years： | 2025 |
| DOI： | 10.1016/j.aquaculture.2025.742590 |
| Abstract： | Skeletal deformities in fish pose a significant economic challenge to the aquaculture industry. Lordosis, a common trunk malformation, affects various farmed fish species, but its exact causes and genetic mechanisms remain unclear. High rates of lordosis were observed in largemouth bass (Micropterus salmoides) and blunt snout bream (Megalobrama amblycephala) fries raised in laboratory recycling aquaria systems, providing valuable research models for exploring the causal factors and the associated genes. Alizarin red staining of lordotic fish revealed an obvious inward curvature of the vertebrae. Body measurements revealed lower body weight in lordotic largemouth bass (LMB) fries compared to normal ones. RNA-seq analysis of trunk tissues from normal and deformed LMB fries identified 118 upregulated genes and 78 downregulated genes in the deformed fish. The upregulation of ostn (Osteocrin), a gene responsive to mechanical forces and involved in bone growth, suggested aeration as a potential cause of lordosis. To test this hypothesis, larvae of LMB and blunt snout bream were raised in glass aquaria with or without aeration, confirming that aeration induced lordosis in both species. Genes associated with bone development, including the ostn, ch25h, alx1, and notum2, showed sensitivity to aeration, with a dose-dependent effect on the occurrence of lordosis in blunt snout bream fries. Furthermore, a field investigation revealed a correlation between aeration and the occurrence of lordosis in large-scale farmed LMB fries. Our findings highlight aeration as a causal factor for lordosis in LMB and blunt snout bream and provide insights into associated genes for the first time. Given the widespread use of aeration in intensive aquaculture, particularly during larvae rearing, our findings offer valuable insights for the industry to prevent aerationinduced lordosis in farmed fish. |
