Histopathological changes in the internal organs of female striped gourami (Trichogaster fasciata) exposed to sub-lethal concentrations of salt water

Abstract

The present study was conducted to evaluate the effects of climate induced salinity on histoarchitecture of liver, kidney and ovary tissue of female striped gourami (Trichogaster fasciata) exposed to
three sub-lethal concentrations (3, 6 and 9 ppt) of crude salt along with a control group (0 ppt) for a period
of 30 days. The 96-h LC50 value of crude salt for striped gourami was previously estimated as 11.107 ppt. To
conduct the experiment 12 plastic tanks each having 70L water holding capacity were used for the four
treatments with three replications for each. Water exchange was done on every 10th day and crude salt was
used to maintain desired salinity. Several histopathological changes were observed in fish liver, kidney and
ovary exposed to different concentrations of salinity. Increasing necrosis, hemorrhage, hepatic rupture,
melano-macrophage cells, degenerated cell and vacuums in the liver tissue were found in salt water treated
groups. Similarly, a number of changes such as, vacuole, cellular degeneration, hemorrhage, disintegrated
glomeruli, destructed renal tubule and extensive vacuolein were observed in the kidney tissue of salt water
treated groups. Degenerated oocyte, inter-follicular space, disrupted oocytes, etc. were observed in ovary
with increasing concentration of salinity and time of exposures. Physiological and metabolic dysfunctions
might have happened to female stripped gourami due to changes in vital internal organs like liver, kidney and
ovary. Therefore, the present research further suggested that climate induced salinity intrusion is capable of
stressing freshwater fishes resulting in deformities of liver, kidney and ovary.