Changes in Glycogen Content During Fin Regeneration

Abstract

Regeneration is the replacement of the lost parts. Amputation was carried out through the ventral and the pelvic fin at a proximal level of Oreochromisaureus. The regeneration process has been divided into five continuous stages: wound healing, dedifferentiation stage, blastema formation stage, early and late redifferentiation and growth stages. The regenerating system was completely formed histologically by about fifteen days post-amputation. During this stage the fin grew by increasing the number of segments, rather than by increasing the length of skeletal elements. By the thirtieth day postamputation, the fin regenerate illustrated the entire histological pattern of fin regeneration. Then the growth of the regenerating fins continued by addition of new lepidotrichial segments to the end of the fin, reaching approximately the normal length and size by the forty-five day. The steady increase of glycogen content in the regenerating fins, reaching its highest level at the early redifferentiation stage met the problem of energetics, much needed during this active proliferated phase. In addition, the decrease in the glycogen content in the liver and muscles during the early phases of regeneration was indicative of the increased energy demands associated with the process of regeneration in the fish body as a whole.