Comparative analysis of site-specific Intestinal Histological variations in Asian Seabass (Lates calcarifer) and Seabream (Nemipterus japonicus) along the Balochistan coast, Pakistan

Abstract

Coastal marine ecosystems are increasingly exposed to anthropogenic pressures that can impair fish health and compromise ecosystem integrity. The intestinal tract of fish is particularly sensitive to environmental stressor making intestinal histology a valuable indicator of habitat quality and environmental impacts. The present study examined site-specific variations in the intestinal histology of Asian Seabass (Lates calcarifer) and Seabream (Nemipterus japonicus) collected from Dam, Gaddani, and Kund Malir along the Balochistan coast, Pakistan. Intestinal tissues were processed using standard histological techniques, and quantitative measurements of villi length and mucosal thickness were used to assess structural alterations among sites. The results revealed significant reductions in villi length (34.79 ± 7.29 µm, p < 0.0001) and mucosal thickness (8.33 ± 1.88 µm, p < 0.05) in L. calcarifer from Dam compared to species from Gaddani and Kund Malir, where no significant differences were observed. Similarly, N. japonicus collected from Dam showed significantly reduced villi length (34.79 ± 7.29 µm, p < 0.001) and mucosal thickness (7.11 ± 1.67 µm, p< 0.05), while individuals from Gaddani and Kund Malir remained normal. These findings indicate that Dam coastal area is subjected to greater environmental stress, highlighting intestinal histopathology as a reliable biomarker for assessing coastal ecosystem health.