THE STRUCTURE AND METABOLISM OF A CRUSTACEAN INTEGUMENTARY TISSUE DURING A MOLT CYCLE

Abstract

Pieces of integumentary tissue, comprised of 2 sheets of epidermal cells separated by connective tissue, were excised from the coverings of the gill chambers of the land crab, Gecarcinus lateralis, at each stage of the molt cycle. The tissues were fixed in Bouin''s solution, dehydrated in ethanol, imbedded in paraffin, sectioned and stained with either Mallory''s triple stain or phosphotungstic acid. RNA was visualized by staining with dilute solutions of methylene blue over a pH range of 3 to 6.2. Glycogen was demonstrated by the periodic acid-Schiff method. The oxygen consumption of integumentary tissue was determined manometrically and the effects of cyanide, dinitrophenol and added substrates were studied. The QO2 reached a maximum at the time when the epithelial cells were synthesizing the exocuticle. Both limb regeneration and gastrolith formation were completed before any structural changes were visible in the integumentary tissue.