Caracterización de las lesiones observadas en el pez Capitán de la Sabana (Eremophilus mutisii) en condiciones de cautiverio

Raising the cold-water catfish Eremophilus mutisii in captivity presents significant challenges due to the rapid development of skin lesions that can progress to erratic swimming and death. This research aimed to characterize the macroscopic and microscopic morphological changes observed in captive catfish E. mutisii. Fifty-seven fish were captured from four municipalities in Cundinamarca, Colombia (Villa Pinzón, Suesca, Cucunubá, and Fúquene). The fish were transported to a production centre and placed in six circular plastic tanks with a capacity of 250 L (9-10 fish per tank). Twelve fish exhibiting severe signs of disease were euthanized for post-mortem examination. Tissue samples were fixed in 10% buffered formalin and stained with haematoxylin and eosin. Lamellar fusion, atrophy, necrosis, and the presence of filamentous bacteria and parasites were observed in the gills. In addition, hepatic necrosis and fatty degeneration were observed, along with lymphocytic exudate, necrocatarrhal dermatitis, haemorrhage, erosions, and skin ulcers with bacillary bacteria, epithelial hyperplasia of the mucosa and necrosis, glomerulonephritis, and lymphoid depletion. It is concluded that the captive breeding of E. mutisii presents difficulties associated with an acute syndrome, which begins with branchial and cutaneous lesions that progress systemically to multi-organ damage. Stress from capture, transport, and confinement acts as a trigger for the disease, favouring colonization by opportunistic pathogens.