Formación inicial de los espermatofóros en el testículo del cangrejo Uca uruguayensis (Brachyura: Ocypodidae) / Initial formation of spermatophores in the testicles of the crab Uca uruguayensis (Brachyura: Ocypodidae)

The functional anatomy of the male reproductive system of Uca uruguayensis from Mar Chiquita lagoon, (37º45' S, 57º26' W), Argentina, was known only from optical icroscopy. The present study describes the participation of vas deferens regions in spermatophore formation. A detailed description of the functional morphology of the different regions of the testicular lobes was carried out using both light and scanning electron microscopy. Spermatophore formation begins at the base of the testicular lobe. In most brachyuran species, the spermatophore starts formation when spermatozoa move from the collecting ducts of the testis to the vas deferens. However, in U. uruguayensis observations suggest that the formation of the spermatophore walls occurred in the terminal region of the testis, and that the spermatophore was formed at the junction of the testis and the vas deferens.

La anatomía funcional del sistema reproductor de los machos de Uca uruguayensis de la población de la laguna de Mar Chiquita (37º45' S, 57º26' W), Argentina, ha sido previamente estudiada empleando microscopía óptica. En el presente estudio se demostró la intervención del vaso deferente, en sus distintas regiones, en la formación del espermatóforo y la inclusión del fluido espermático. Se amplía la descripción de la morfología funcional de las regiones de los lóbulos testiculares (empleando también microscopía electrónica de barrido). La formación de los espermatóforos se inicia en la base del lóbulo testicular. El mecanismo descrito hasta el momento para la mayor parte de las especies de braquiuros postula que los espermatóforos comienzan a formarse cuando los espermatozoos pasan de los colectores del testículo al vaso deferente. Nuestras observaciones sugieren sin embargo, que en esta especie la formación de la pared del espermatóforo se inicia en la base de los lóbulos testiculares, y que los espermatóforos están completamente formados en la unión de los testículos y el vaso deferente anterior.

Fine structural analysis of the epithelial cells in the hepatopancreas of Palaemonetes argentinus (Crustacea, Decapoda, Caridea) in intermoult

The aim of this study is to describe the ultrastructure of the hepatopancreas of P argentinus in intermoult. P argentinus hepatopancreas was studied using standard TEM techniques. Each tubule consists of four cellular types: E (embryonic), F (fibrillar), R (resorptive) and B (blister like). E-cells have embryonic features and some of them were found in mitosis. F, R and B cells possess an apical brush border. F-cells have a central or basal nucleus, a conspicuous RER, and dilated Golgi cisternae. R cells show a polar organization of organelles in three areas: apical, with numerous mitochondria and sER tubules, a central are a with the nucleus and RER, and a basal area containing a sER-like tubule system and mitochondria. B-cells were observed at different stages of their life cycle. In an early differentiation stage they comprise an apical endocytotic complex and Golgi vesicles. The fusion of endocytotic and Golgi vesicles originates subapical vacuoles. During maturation, a big central vacuole is formed by coalescence of subapical vacuoles. The central vacuole is eliminated by holocrine secretion. The ultrastructure suggests that F-cells synthesize proteins, R-cells storage nutrients and B-cells have a secretory or excretory function, and confirms the independent origin of F, B and R cells from the embryonic cells