The histopathological alterations of the thyroid of Epinephelus coioides affected by Vibrio alginoliticus

In this study, to evaluate the histopathological effects of V. alginolyticus (one ofopportunistic pathogens in saltwater fish) on the thyroid of Orange-spotted grouper(one of the most important commercial fish in Persian Gulf), 50 E. coioides with amean body weight of 180 ± 7.9 g were selected and studied for two weeks. The firstgroup (control) received no injection and the second group, the concentration of 10 7cfu/ mL V. alginolyticus was injected. On the days 1, 4, 7 and 14, tissue samples fromthe fish s pharyngeal region was collected. After histological processing laboratory,the samples were stained by hematoxylin - eosin (H & E) and examined using anoptical microscope (Olympus). In the control group, there were some follicles withpink colloid and columnar follicular cells. On the first and fourth day, in bacteriagroup, no effect was found, however, on the seventh day, the enlargement of thethyroid follicles, decrease of the thyrocyte height and decrease of colloid, comparedwith the control, was observed. On the fourteenth day, the same effects were observedwith a lower intensity.

Keywords:

Vibrio alginolyticus , Pathogen , Epinephelus coioides , Histopathology , Thyroid