Population structure of Uncancylus concentricus (d'Orbigny, 1835) (Ancylidae, Pulmonata, Basommatophora) in the Multiple Use Reserve Martín García Island, Upper Río de la Plata, Argentina

Abstract

The present work analyzes the population dynamics of Uncancylus concentricus in natural conditions in the northeastern coastal area of the Multiple Use Natural Reserve Isla Martín García (Beach of Basural), Buenos Aires, Argentina. Martín García Island is located in the Upper Río de La Plata, to the south of the mouth of the Uruguay River (34° 11' 25" S and 58° 15'38" W). Monthly collections were made from August 2005 to December 2006. The size frequency of the U. concentricus population throughout the sampling period ranges from 1.2 to 8.3 m. The changes in the size frequencies throughout the months surveyed indicate a variable distribution pattern because of the increase and decrease in water flow, but we observed a peak in the frequency of individuals within the size range 3.5 to 4.5 mm in the population. It can be concluded that this species lives for at least a year in the wild since the juveniles are highly abundant in spring and summer.

A New Species of Uncancylus Pilsbry, 1913 (Gastropoda: Hygrophila: Planorboidea: Ancylinae), from South America and Reassessment of the Status of U. bonariensis Strobel, 1874

“…Uncancylus concentricus is probably the best known of all described species of Uncancylus, both in terms of morphology and distribution. This species has been recorded in Central and South America from Costa Rica (Hubendick, 1964, 1967; Pilsbry, 1920; Lanzer & Veitenheimer-Mendes, 1985; Lanzer, 1996) to southern Buenos Aires, Argentina (Santos, 2003; Santos et al, 2009; Martin & Diaz, 2012; Ovando et al, 2014). Details of its morphology and microsculpture have been documented by numerous authors (Hubendick, 1964, 1967; Lanzer, 1995, 1996; Santos et al, 2009; Ovando et al, 2014).…”

Individual growth of Drepanotrema cimex (Pulmonata: Planorbidae) from Arenalcito pond, natural reserve multiple uses Martin García Island, Buenos Aires, Argentina

“…To date, several investigations have been carried out on the ecology and biodiversity of the Reserve's fauna and flora Hurrell, 1996 and1997;Rumi et al, 1996;Martín and Negrete, 2006;Martín 2008;César et al, 2008;Martín et al, 2009;Martín and Díaz, 2012).…”