The Fine Structure of the Liver Cell in Larval and Adult Brook-Lamprey, Entosphenus reissneri, Observed by Electron Microscope

Abstract

In the course of metamorphosis from ammocoetes to adult in Entosphenus reissneri, a land-locked lamprey in the streams of Japanese Islands, the gall bladder.and its duct disappear, also, cells in the liver undergo a marked change. The liver cells of both ammocoetes and adult forms of the species are observed by electron microscope.
Larval forms-nter-and intrabile canaliculi are clearly recognized with well-developed microvilli.Endoplasmic reticula with rough surface are normal.Golgi complexes are abundantly accumulated near the bile canaliculi.Golgi vesicles (or vacuoles) contain electrondense bodies which are believed to represent granules at some stage playing a role in the production of bile.Mitochondria are well developed, besides the passing in the bile canalicules of myelin-like bodies of various types.
Adult forms-Neither internor intracellular bile canaliculi are present.Endoplasmic reticula with rough-surface are formed in stratification.Golgi complexes are typical in general, but of ten accumulation of concentric circles. Mitochondria are regular in form in most cases.