Estudo histológico dos processos regenerativos da nadadeira caudal do patinga, híbrido de pirapitinga (Piaractus brachypomus) e pacu (Piaractus mesopotamicus)

Abstract

After partial amputation, teleostean tail fins suffer a regenerative process capable of quickly restoring its original size and shape. This process is called epimorphic regeneration and it is characterized by the following stages: the healing, based on the formation of a multistratified epidermal layer, the formation of a mass of pluripotent cells known as blastema, the differentiation of these cells, the synthesis and disposition of the extracellular matrix, the morphological growth and restoration. The most common fish used in experiments performed on fin regeneration is the zebrafish, the carp and the tilapia. So far, no studies were done on the regenerative process of the fins in Brazilian species. Thus, the objective of this work was to study the regenerative process of the tail fin of the patinga (a hybrid from the crossing of the female pirapitinga and the male pacu). For this purpose, the fish were anesthetized and had their tail fins transversally amputated 3mm from the tail muscular peduncle. After 1, 2, 4, 6, 8 and 10 days of regeneration, the fins were collected, fixed and processed in order to allow the light microscope study. It was observed that the tail fins of the patinga show the same regenerative pattern already known of the zebrafish, the carp and the tilapia, which means that the regenerative process occurred in a fast and precise way, and in the same sequence of the events already known and described. Therefore, we believe that this specie is equally useful for future studies concerning, for example, biotic and abiotic effects of this process, as well as for molecular biological studies.