Evaluation of somatic indexes, hematology and liver histopathology of the fish Labrisomus philippii from San Jorge Bay, northern Chile, as associated with environmental stress

Abstract

The health condition of Labrisomus philippii specimens inhabiting San Jorge Bay (northern Chile) which is characterized by high heavy metal contents was studied. Additionally, heavy metals concentrations in fish livers were determined. Fish were captured through apnea diving, from two sites: Club Yates (CY, n = 26) and El Colorado Beach (EC, n = 33) exposed to high and low levels of anthropogenic activities respectively. Live specimens were transported to the laboratory where macroscopic observations were carried out. Each fish was measured (total length) and weighed (total, liver and gonads weights). Blood samples were obtained from the cardiac region of each specimen. Condition factor (CF), hepatosomatic (HI) and gonadosomatic (GSI) indices, and hematological parameters (counts of lymphocytes, granulocytes ad monocytes) were determined. Fish livers were histologically analyzed. Fish size was not correlated with HI and CF. There were not significant differences in CF and HI between fish sexes. Fish from the CY site showed higher HI and CF. Fish size was positively correlated with the number of lymphocytes, and negatively correlated with granulocytes, whereas there was no correlation between fish size and number of monocytes. The most frequent liver lesions were vacuolar degeneration (62% CY and 30% EC) and steatosis (23% CY and 17% EC); followed by necrosis, autolysis, and fibrosis. Our results suggest that the impairment health of individuals L. philippii in San Jorge Bay, and especially in those specimens living in CY, might be associated with metal pollution. Key