www.mdpi.com/journal/ijerph Article Histological Changes in Gills of Two Fish Species as Indicators of Water Quality in Jansen Lagoon (São Luís,

Abstract: Water quality of the Jansen Lagoon (São Luís, Maranhão State, Brazil) was assessed through histological biomarkers and microbiological parameters. To this end, 29 fish specimens (11 Centropomus undecimalis and 18 Sardinella sp) and eight water samples were collected during the rainy and dry periods of 2013. The lagoon water showed thermotolerant coliform indices above the limit set forth in CONAMA Resolution 357/2005. Histological changes observed in the gills were: lifting of the respiratory epithelium, hyperplasia of the lamellar epithelium, incomplete and complete fusion of several lamellae, disorganization of the lamellae, congestion of blood vessels, aneurysms, hypertrophy of the respiratory epithelium, hemorrhage and rupture of the lamellar epithelium and parasite. The histological alteration index (HAI) average value to Sardinella sp was 31.8 and to C. undecimalis was 22.2. The average HAI value in both OPEN ACCESS Int. J. Environ. Res. Public Health 2014, 11 1292