Avaliação morfológica do aparelho reprodutor masculino e morfometria dos testículos de Chromacris speciosa (Thunberg,1824) (Orthoptera : Romaleidae) submetido a três fotoperíodos

Abstract

The alimentary regimen of the Orthoptera is varied, practically from the monophagy to the polyphagy, prevailing, however, the phytophagy, thus being highly harmful to cultivated plants and, therefore, economically important under agricultural perspective. Chromacris speciosa (Thunberg, 1824) (Orthoptera: Romaleidae) is considered as occasional endemic species in South America feeding on several type of plants. Studies about morphology of the male reproductive system as well as the sperms of some insects have contributed to the understanding of relationship affinity among groups. Thus, the present research had the objective of describing the histology of the male reproductive system constituents, realizing the morphometry of the testicles and the population of the cells from testicular follicles, besides analyzing ultrastructurally the spermiogenesis in C. speciosa, reared under the photoperiods of 14L:10D, 10L:14D and 12L:12D, in the last instar. The testicles were measured before fixation using a binocular magnifying glasses adapted with a milimetric ocular. For the morphometric analysis of cell population of testicular follicles, it was used a 10X ocular, containing a square micrometric reticule (U-OCMSQ10/10). The averages were submitted to the analysis of variance. For the analysis in electronic microscopy of transmission and sweeping, the testicles and testicular follicles were fixated in Karnovsky. The results showed that there wasn't influence of the photoperiods over the organs' histology, testicles' morphometry and cell population of the testicular follicles, besides the spermiogenesis. The testicles presented oval morphology and were involved by a connective tissue capsule. In each testicular follicle, the regions of the germary, growth zone, division and reduction zone, and transformation zone were well evinced. The efferent and deferent canals, and the seminal vesicles are internally covered by a simple cubic epithelial layer of tissue, except in those vesicles in which the epithelium is columnar, sustained in connective tissue, and, externally, grooved muscular tissue, which is absent in the efferent canal. The ejaculator duct is constituted by a columnar stratified epithelium covered by an intima in its final part. Underneath this epithelium it is observed connective tissue. The accessory glands secrete substances rich in carbohydrates and are constituted by epithelial, connective and muscular tissue. Ultrastructurally it has been observed spermatids in advanced stages of differentiation, and others in more precocious stages. The spermatids in initial stages of development are big, with spherical morphology and voluminous nucleus, while the more differentiated spermatids are smaller, being possible to observe the presence of axoneme and parallel mitochondria for this last one. The sperms are grouped in bunches, in which it has been observed the axoneme and typical mitochondrial derived, characteristics of the intermediate part and tail. In the head region, the nucleus is stretched, elliptical and very electron-dense.