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Histology and ultrastructure of hepatic nodular alterations in C larias gariepinus (Burchell, 1822)
Author(s) -
Lukhwareni Refilwe,
Dyk Cobus
Publication year - 2018
Publication title -
journal of fish diseases
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.819
H-Index - 85
eISSN - 1365-2761
pISSN - 0140-7775
DOI - 10.1111/jfd.12900
Subject(s) - ultrastructure , biology , histology , endoplasmic reticulum , clarias gariepinus , pathology , nucleolus , anatomy , hemosiderin , cytoplasm , catfish , microbiology and biotechnology , fish <actinopterygii> , fishery , medicine , genetics , immunology
This study aimed to assess the macroscopic appearance, histology and ultrastructure of liver nodular alterations in sharptooth catfish Clarias gariepinus (Burchell, 1822) from a hyper‐eutrophic freshwater impoundment. The livers of 25 fish were sampled for microscopy analyses, otoliths were collected for age estimation, and the hepatosomatic index ( HSI ) was calculated. The light microscopic analysis of the nodular tissue revealed hepatocellular and nuclear pleomorphism, pyknotic nuclei, variation in cytoplasmic appearance and focal areas of cellular alterations ( FCA s). An increase in the size and number of melano‐macrophage centres, intracellular deposits, steatosis and giant cells was also identified. The ultrastructural alterations identified included cell membrane disruption, irregular shaped nuclei with augmentation of the nucleolus and deformed nuclear envelopes. In addition, we found dilation, proliferation, fragmentation and vesiculation of the cisternae of the rough endoplasmic reticulum ( RER ). Furthermore, there was an increase in degenerative mitochondria (transparent matrix), swelling of mitochondria and proliferation of both peroxisomes and lysosomes. The histological and ultrastructural alterations identified did not explain the variation in macroscopic colour of the nodules. We did not find a strong positive correlation between age and HSI ; however, the oldest fish (18 years) did present the most nodules.