Liver morphology and histological alterations related to reproductive phases of female silver croaker Plagioscion squamosissimus (Acanthuriformes, Sciaenidae).

Abstract

This study describes the morphology of the liver tissue, histological alterations, and their relationships with the reproductive phases of the female silver croaker Plagioscion squamosissimus. We tested the hypothesis that histological alterations in liver tissue can occur at the expense of the reproductive phase of the female and that climatic factors, such as rainfall, interfere with the reproductive phases and, consequently, promote histological alterations. Histological analysis of the liver showed liver tissue with hepatocytes, bile ducts, blood vessels, sinusoids, intrahepatic pancreas, and phagocytic cells. The histological alterations observed were vacuolization and cytoplasmic degeneration, aggregates of melanomacrophages, hyperemia, and vascular congestion, with cytoplasmic vacuolization, cytoplasmic degeneration, and vascular congestion being the most frequent. We observed that the frequency of cytoplasmic vacuolization increased throughout gonadal development with a decrease in the spawning-capable phase, and that cytoplasmic degeneration and vascular congestion were more frequent in the suitable spawning phase. In addition, relationships between histological alterations, hepatosomatic index, gonadosomatic index, reproductive phases, and rainfall were also observed, showing that alterations were more frequent in periods with higher rainfall and reproductive phases when females were ready to reproduce. In short, histological alterations may be subject to the reproductive phases of females, which are influenced by rainfall, as observed in many studies. Thus, this study presents the morphology of the liver tissue of P. squamosissimus, and the results shed light on the importance of considering the reproductive phases in studies evaluating histological alterations in the liver.