Speaker: Bailey Lovett, PhD Candidate, The University of Auckland
Topic: Characterising the development of spinal curvature in farmed New Zealand Chinook salmon Oncorhynchus tshawytscha
Spinal anomalies are a frequent cause of economic loss in intensive finfish aquaculture and raise ethical concerns. However, there is a general lack of consensus about the relationships between different anomaly types, their pathologies and the factors which contribute to their development. Novel cases must therefore be investigated independently. Chinook salmon (Oncorhynchus tshawytscha) farmed in New Zealand (NZ) are known to develop spinal curvatures in the form of lordosis, kyphosis, and scoliosis, but their cause and much about their pathology is unknown. Using X-ray radiography, dual-energy X-ray absorptiometry (DXA) and magnetic resonance imaging (MRI), we characterized the bone and soft tissue changes associated with curvature development in commercial populations of NZ Chinook salmon. We discovered that the curvatures collectively constitute a late-onset LSK (lordosis-scoliosis-kyphosis) curvature complex which appears radiographically in the last 7 months of production and induces secondary changes to the vertebral bodies, namely compression. While DXA-determined body composition did not differ between fish affected and unaffected by curvature, MRI revealed that the curvatures were strongly associated with progressive stages of inflammation and fibrosis of the peri-vertebral musculature and connective tissues, indicating a neuromuscular pathology. While the contributing factors remain to be elucidated, development of the condition may be related to altered mechanical load caused by high intensity exercise, excessive musculature, fast growth, handling and transport stress, temperature, and/or insufficient bone mineralization during the early seawater phase. Future research evaluating the magnitude of muscular forces applied to the spine during swimming and the integrity of peri-vertebral connective tissues and vertebral bone may help to identify which factors are the most likely contributors.
Link: Join Zoom Meeting https://oregonstate.zoom.us/j/94555731151
Thursday, July 30 at 3:30pm to 4:40pmVirtual Event