Morphological and Histological Analysis of Muscles and Liver Tissues in Selective Fish Species evidence based at Costal belt in Balochistan

Abstract

Histopathological changes in fish muscle and liver tissues serve as reliable bioindicators of aquatic pollution and ecological stress. This study analyzed seabream (Nemipterus japonicus) and Seabass (Lates calcarifer) from three coastal sites of Balochistan Gadani, Dam, and Kund Malir represented high, moderate, and low anthropogenic influence, respectively. Muscle and liver samples from posterior and caudal regions processed to use hematoxylin and eosin staining to assess fiber dimensions and tissue integrity. Muscle fiber thickness in Lates calcarifer from Dam (4.758 ± 0.813µm) was significantly lower than in Kund Malir (5.623 ± 0.739µm; p < 0.01), while fiber length showed no significant variation (24.76-5.195µm; p > 0.05). Histological observations revealed severe hepatic vacuolar degeneration, sinusoidal cells arrangement, and muscle necrosis in Gadani specimens, moderate tissue alterations in Dam fish, and normal architecture in Kund Malir samples. The findings demonstrate that environmental stress and pollution strongly influence fish tissue structure, confirming Gadani as the most impacted and Kund Malir as the least affected site. Additionally, the study emphasizes the importance of continuous biomonitoring and sustainable management of the Balochistan coast, support the histopathological biomarkers as sensitive indicators of environmental quality.