Mantle and Its Protective Role of the Slipper-shaped Oyster (Crassostrea Iredalei) in Response to Crude Oil

Abstract

The mantle plays important role in the mechanism of oyster protection caused by environmental pollutants. This study aims to analyze the effect of water accommodated fraction of crude oil on the mantle of Slipper-Shaped Oyster (Crassostrea iredalei) at different doses and time exposure. The ventral and posterior segments of the mantle were fixed, and tissue sections were stained with hematoxylin-eosin, PAS-Periodic acid–Schiff, and TEM-transmission electron microscopy techniques. HE-hematoxylin and eosin, PAS-alcian, and TEM-transmission electron microscopy were used to characterize the different mucosubstances and to describe the ultrastructure-related response on a certain part of the mantle after exposure. The tissues of epithelium, connective tissue, mucus cells, pigmented cells, numerous hemolymph sinuses, shell formation, and blood sinus were recognized under a light microscope. The mucous cell was excreted in all the concentrations (control, 12.5, 25, 50, and 100% Water Acomodate Fraction) and also in the time exposure (24, 48, 72, and 96 hours). A large number of mucous cells was produced in the inner mantle cavity (IMC) and outer mantle cavity (OMC). Mucous cells increased in number with increasing WAF concentration as well as the length of exposure time. The highest number of mucus cells was observed at 100% Water Accommodate Fraction (WAF) concentration and 96 hours of exposure. The structure and function of the mantle, the shell formation, the edge of the mantle, mucous cell, muscle bundles, nerve fibers, and epithelium layer of the Slipper-Shaped Oyster (Crassostrea iredalei) were documented in this study.