Towards a classification and an understanding of developmental relationships of vertebral body malformations in Atlantic salmon (Salmo salar L.)

Unilateral perivertebral fibrosis associated with lordosis, kyphosis and scoliosis (LKS) in farmed Chinook salmon in New Zealand

“…While defects in vertebral bone development are hypothesized to cause most spinal deformities in Atlantic salmon (Fjelldal et al 2012b, Boglione et al 2013b, the possibility that perivertebral inflammation and fibrosis could cause spinal curvature in Atlantic salmon has been previously suggested (Kvellestad et al 2000). Additionally, the possibility that LKS in Atlantic salmon has a neuromuscular rather than a bone aetio logy has also previously been hypothesized (Witten et al 2009). If perivertebral fibrosis is the cause of the LKS in Chinook salmon, this would suggest that LKS in Chinook salmon is similarly not a bone disorder, and would support the hypothesis that LKS in fish can have a neuromuscular origin.…”

“…Not all fish have the same number of vertebrae, and this variation is included in region 4. The radiographs were evaluated for 4 abnormality types including LKS (types 14, 15, 16), fusions (types 6, 7, 8), compressions (types 1, 2, 3, 4, 5) and vertical shifts (type 17) (Witten et al 2009). …”

“…Additionally, the presence of severe deformities can also reduce the value of the fish due to difficulties during processing and the presence of increased connective tissue in fillets from affected fish (Haugarvoll et al 2010). Twenty different spinal deformity subtypes have been described in Atlantic salmon (Witten et al 2009). In this species, vertebral compressions and fusions are reported most frequently and are suspected to be the result of altered vertebral bone development (Witten et al 2005, 2006, Fjelldal et al 2007).…”

“…In contrast, vertical or horizontal curvature of the spine (lordosis, kyphosis, scoliosis: LKS) is rare in farmed Atlantic salmon (Boglione et al 2013b). LKS can occur without underlying bone changes, and a neuromuscular rather than bone-related aetiology has been proposed (Witten et al 2009). Currently, factors thought to influence the development of spinal deformities in farmed Atlantic salmon include water conditions such as temperature and currents, nutritional factors, mineral or vitamin deficiencies (especially phosphorus and vitamin C), toxicities, genetics, trauma, vaccination, swim bladder dysfunction, weight at smoltification, growth rate of the fish and infectious agents (Silverstone & Hammell 2002, Gil-Martens 2010, Boglione et al 2013b.…”

Normal and histopathological organization of the opercular bone and vertebrae in gilthead sea bream Sparus aurata

“…Although the improvement and refinement of rearing techniques have considerably reduced the frequency of these types of deformities (Boglione et al 2013a), lordosis and kyphosis are still 2 of the most relevant osteological abnormalities observed in the axial skeleton of reared gilthead sea bream, while a partial and/or total lack of operculum is the most frequent anomaly affecting its cranial region (Koumoundouros et al 1997b, Boglione et al 2001, 2013b, Beraldo et al 2003, Verhaegen et al 2007, Castro et al 2008, Koumoundouros 2010, Prestinicola et al 2013). Several studies have described skeletogenesis in gilthead sea bream (Faustino & Power 1998, 1999, 2001) and the typology of fish skeletal deformities (Witten et al 2009, Boglione et al 2013b, Prestinicola et al 2013, among others) in order to better understand the phases of skeletogenesis and the effects of biotic and abiotic factors on the proper development of bone and the appearance of skeletal anomalies. Various procedures have been used as simple and rapid diagnostic tools for studying skeletal deformities in fish, such as X-rays, double staining or even computer tomography; allowing the identification of abnormal growth in different skeletal structures (see reviews in Witten et al 2009, Koumoundouros 2010, Boglione et al 2013b.…”