title: Histology and gametogenesis inHeleobia piscium(Cochliopidae) from the Multiple Use Reserve "Isla Martín García," Buenos Aires, Argentina.
abstract: Heleobia piscium(d'Orbigny, 1835), a member of the Cochliopidae family found only in South America, is distributed from Entre Ríos, Delta del Paraná, and the littoral of the Río de la Plata down as far as to Punta Indio (Buenos Aires), the southernmost limit of the snail's geographical distribution. To date, little information is available regarding the reproductive cycle of species within this family either in Argentina or throughout South America. The present work analyzed the histology of the reproductive system of the gonochoric speciesH. pisciumand determined the stages oogenesis and spermatogenesis under natural conditions. Specimens ofH. pisciumwere collected in the Multiple-Use Natural Reserve Isla Martín García, located in the Upper Río de la Plata estuary to the south of the mouth of the Uruguay River. The gametogenic cycle in both sexes was found to consist of the following stages: early maturation, maturation, and evacuation. The maturation period was found to extend from January to October and evacuation of the gametes to start in November and end in February (summer in the Southern Hemisphere). The results indicated theH. pisciumexhibit a reproductive cycle without a resting period.
authors.affiliation: División Zoología Invertebrados-FCNyM-UNLP-Investigador Independiente CIC, Universidad Nacional de La Plata , Buenos Aires , Argentina.
authors.forename: Stella Maris
authors.initials: SM
authors.lastname: Martin
authors.affiliation: División Zoología Invertebrados-FCNyM-UNLP-Becaria Doctoral CONICET, Universidad Nacional de La Plata , Buenos Aires , Argentina.
authors.forename: Ana C
authors.initials: AC
authors.lastname: Díaz
keywords: Argentina; Gametogenesis; Heleobia; Histology; Isla Martín García