Salinity tolerance and gill histopathological alterations inLiza aurataRisso, 1810 (Actinopterygii: Mugilidae) fry

Abstract

Gill histopathological alterations in Golden Grey Mullet, Liza aurata, fry in acute salinity exposure were studied by light and scanning electron microscopy (SEM). The Golden Grey Mullet fry was obtained from the south of the Caspian Sea and acclimated to brackish water (12 ppt). Fry (adapted in 12 ppt salinity) were transferred directly to salinities of 40, 45, 50, 55, 60, 65 and 70 ppt. Mortality occurs more rapidly over a narrow range of salinity from 45 to 60 ppt. Mortality was 100% in salinity higher than 60 ppt. Histopathological gill alterations included edema of the epithelial cells with the breakdown of pillar cells, hypertrophy and hyperplasia of epithelial and chloride cells. According to SEM observation, two types of chloride cells were identified in gill of L. aurata fry. In Type I, crypts usually had large openings and were occasionally ornamented with short microvilli, and, in Type II, crypts resembled a narrow and deep hole. The number of Type II increased following elevated salinity. lethal concentration 50 (LC 50 ) 24-, 48-, 72-and 96-h values calculated with the probit method were 50.11, 49.91, 49.91 and 49.91 ppt, respectively. This study showed that the gill was the primary target organ for the acute effects of salinity. Moreover, the type of chloride cells and gill structure is affected by acute salinity such that these alterations must be one of the reasons for death in some treatments.

The Study of Caspian Roach (Rutilus caspicus) Fry Health Fed with Phytobiotic-Supplemented and Salinity Stress Resistance with Emphasis on Gill Tissue Pathology

“…Therefore, histopathological changes in gills and other organs (such as the liver and kidney) can be used as an indicator in evaluating the effects of various types of stress in fish (especially salinity). Chloride cells in the epithelium of the gills are the most important cells for ion exchange, and the structure of these cells changes with changes in the salinity of the environment [13]. Since fish are in direct contact with the surrounding aquatic environment, changes in the physicochemical parameters of water such as salinity affect them.…”

“…Therefore, histopathological changes in gills can be used as a marker to evaluate the effects of salinity on fish. Chloride cells in the epithelium of the gills are the most ion exchange cells, and environmental salinity fluctuations change the structure of these cells [13]. Since the fish are in direct contact with the surrounding aquatic environment, changes in the physicochemical parameters of the water such as salinity affect the physiological response of the fish [14].…”

Gene expression profiling and physiological adaptations of pearl spot (Etroplus suratensis) under varying salinity conditions

“…Shahriari Moghadam et al (2013) investigated the primary target organ for acute salinity effects in Liza Aurata and reported that it affects the type of chloride cells and gill structure.…”