Abstract
The gill is the respiratory organ in fish but it is also responsible for ion exchange with the environment, what makes it highly susceptible to pollutants. This study aimed to identify possible histological and histochemical changes in the gill of fish species Prochilodus lineatus exposed to biodegradable detergents and water from an urban lake. The results showed not only morphological alterations such as lamellae fusion and hyperplasia, as well as increase in collagen, changes in nuclear volume and increase in the number of chloride and mucous cells. These results show that common pollutants dumped into rivers and urban lakes can cause several changes in the respiratory organ, possibly leading to a metabolic deficit in fish.
Highlights
According to Pough et al [1], most of aquatic vertebrates have gills, which are specialized structures for gas exchange, placed in the pharyngeal pouches in fish
Analysis showed secondary lamellae fusion and changes in gill morphology on individuals exposed to polluted environments, both in the detergent group and in the Blue Lake group throughout the experiment (Figure 1)
The slides submitted to the Feulgen reaction showed increase in the nucleus size of epithelial cells, which are found at the edges of hypertrophied secondary lamellae, both in the detergent and in the Blue Lake group (Figure 2B)
Summary
According to Pough et al [1], most of aquatic vertebrates have gills, which are specialized structures for gas exchange, placed in the pharyngeal pouches in fish. According to Pough et al [1], the water flow is usually unidirectional, entering through the mouth, passing over the gills and exiting through the operculum. The gills, which should be permeable to oxygen and carbon dioxide, are permeable to water and as a result, most of the movements of water and ions occur through the gill surface. The chloride cells are large, scattered on the lamellar surface, rich in mitochondria and act in the transportation of active ions [2,3]. Due to a large number of mitochondria in these cells, they are known as mitochondria-rich cells or MRC [4]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
