Histologia e ultra-estrutura do vaso dorsal de Scaptotrigona postica (Hymenoptera, Apidae) em operárias e rainhas de diferentes idades

Abstract

The dorsal vessel is a tubular organ located in the mid-dorsal region of the insects body, just below the tegument. This work is a light and electron microscopy study of the abdominal part of the vessel, the heart, in a stingless bee species. Workers and queens of several ages were studied. The heart is located inside the pericardial sinus. Its wall presents openings or ostia provided with valves and is composed by special striated muscular fibers. The cardiac fiber presents myofibrils irregularly arranged, round or elongated nuclei, numerous and large mitochondria, and glycogen deposits. Old workers and queens present fibers degeneration, represented by autophagic vacuoles, mitochondria alterations and accumulation of myelinic bodies. In conclusion, the heart of Scaptotrigona postica Latreille, 1807 is similar to other insects. The changes found are related to aging progress and maintain temporal relationship with the caste life expectancy.