Certain aspects of the reproductive dynamics of Argentine red shrimp Pleoticus muelleri (Bate, 1888), distributed between 42°-47°S and 62°W, were investigated. Data and samples were collected during 36 INIDEP research cruises and 87 commercial fishing fleet trips between 1994-2010. Mature and inseminated females size structure as well as the frequency distribution of macroscopic maturity stages of adult females were analyzed on space-time bases. The seasonal development of ovarian maturity stages microscopically determinated was also assessed. Statistical treatment of data included multivariate scaling and cluster analysis. The reproductive activity of the shrimps showed latitudinal differences concerning its onset and duration that could be associated with the variability of environmental conditions. We discuss a shoreward movement of spawning females related to the presence of coastal hydrographic processes that would ensure retention and food for survival of early life stages.