Seasonal Ultrastructural Modulations of the Molting gland -Y organ in the fresh water crab “Barytelphusa Guerini”

Abstract

The Y-organ in crustaceans plays a crucial role in regulating molting through the synthesis and secretion of ecdysteroid hormones. The present study investigates seasonal ultrastructural variations in the Y-organ of the freshwater crab Barytelphusa guerini to understand its functional adaptations under changing environmental conditions. Specimens were collected across different seasons, and Y-organs were processed for transmission electron microscopy to examine cellular and subcellular alterations. Ultrastructural observations revealed significant seasonal modulation in organelle organization, including variations in mitochondrial density, smooth endoplasmic reticulum proliferation, nuclear morphology, and secretory vesicle abundance. Enhanced development of mitochondria and smooth endoplasmic reticulum during pre-reproductive and reproductive period indicates elevated steroidogenic activity associated with active molting phases. Conversely, reduced organelle complexity and increased cytoplasmic inclusions during post reproductive period suggest lowered metabolic and endocrine activity. These findings demonstrate that the Y-organ exhibits pronounced environmental fluctuations and molting physiology. The study provides insights into endocrine regulation and adaptive strategies of freshwater crabs, contributing to a better understanding of crustacean reproductive and growth cycles in fluctuating freshwater ecosystems.