Report of blended vertebral deformity in the caudal region of narrow-barred Spanish mackerel, Scomberomorus commerson (Lacepede, 1800), from India: A case study

Abstract

Among the four available seerfishes (Scomberomorus commerson, S. guttatus, S. lineolatus, and Acanthocybium solandri) along the Indian coast, S. commerson (27,334 tonnes) is a significant contributor to the seerfish landings. The trawlers from the Versova fish landing centre carried out fishing operations between 20°21′21.29ʺ N, 19°55′03.01ʺ N latitude and 72°36′24.32ʺ E, 72°36′12.23ʺ E longitude in the depth ranges from 5 to 50 m. An abnormal specimen of seerfish was collected from the trawler landed at Versova fish landing centre from the Mumbai, Arabian Sea. The collected specimen was compared with the typical 46 specimens, which showed similar morphological characteristics except for the vertebral deformity near the caudal region (Lumber portion). The deformed fish was radiographed, which showed a distal malformation at about 40th to 49th amphicoelomic vertebral bone. The current work reports blended vertebral column deformity, particularly in the caudal region (a combination of Scoliosis-Lordosis-Kyphosis or LSK syndrome) in a large Narrow-barred Spanish mackerel (S. commerson) specimen from India. In the present study, the exact cause for such a deformation could not be established; however, the possible reasons behind the vertebral deformity are discussed.