Histological and histochemical aspects of the penial glands of Girardia biapertura Sluys, 1997 (Platyhelminthes, Tricladida, Paludicola)

Abstract

Girardia biapertura was described with sperm ducts penetrating the penis bulb, subsequently opening separately at the tip of the penis papilla and receiving the abundant secretion of penial glands. In the present work, the penial glands of this species have been histologically and histochemically analysed, and four types of secretory cells are distinguished. The openings of the penial glands into the intrabulbar and intrapapillar sperm ducts, designated here as intrapenial ducts, allow for the distinction between three histologically differentiated regions. The most proximal region possibly corresponds to the bulbar cavity of other freshwater triclads whereas the median and distal portions correspond to the ejaculatory duct. The proximal region of the intrapenial ducts receives mainly the openings of a secretory cell type (type I) that produces a proteinaceous secretion. A second type of secretory cell (type II) that secretes neutral mucopolyssacharides opens into the median region of the intrapenial ducts. The distal portion of the ducts receives two types of secretory cells (types III and IV) which secret glycoprotein and glycosaminoglycans, respectively. Types III and IV open also directly into the male atrium through the epithelium of the penis papilla. A comparison with the results presented here and those of other authors for species of Girardia is provided and the importance of the study of the penial glands for taxonomic characterisation of freshwater triclads is emphasised.

Empleo De La Regeneración De La Planaria De Agua Dulce Girardia Festae (Borelli, 1898) (Tricladida: Dugesiidae) Para Evaluar La Toxicidad Del Carbofurano*

“…Debido a su extraordinaria capacidad para la regeneración y para la reproducción asexual, las planarias han sido empleadas como organismos modelo para estudiar los mecanismos celulares y moleculares que conducen a la regeneración tisular (Santos & Hauser, 1984;Hauser & Santos, 1985;Shinozawa et al, 1995;Guecheva et al, 2001;Inoue et al, 2004;Hwang et al, 2004;Reddien et al, 2004;Sánchez-Alvarado, 1999;Coward et al, 2005). Las planarias son importantes componentes de los ecosistemas límnicos, algunas tienen amplia distribución geográfica, son sensibles a contaminantes, poseen alta capacidad de regeneración y son de fácil cultivo bajo condiciones de laboratorio (Nano et al, 2002;Souza & Leal-Zanchet, 2002;Inoue et al, 2004;Sánchez-Alvarado, 2004).…”