Variation in the distribution of Corbicula species (Mollusca: Bivalvia: Corbiculidae) after 25 years of its introduction in the Río de la Plata, Argentina

Yamila Reshaid,María Ortiz Blanche,Francisco Brea,Gustavo Darrigran,Luciana Cao,Santiago Torres

doi:10.3897/zoologia.34.e22181

Yamila Reshaid, María Ortiz Blanche + Show 4 more

Open Access

https://doi.org/10.3897/zoologia.34.e22181

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Abstract

In 1981, Corbiculafluminea (Müller, 1774) and C.largillierti (Philippi, 1844) were recorded at the Río de la Plata River. During the 1980’s, C.largillierti was found on a continuous fringe in the shore of that river, while C.fluminea was only found North of Buenos Aires’ harbor. Ten years later, C.fluminea spread to Punta Indio, while C.largillierti remained restricted to tributary streams. The density and size frequency distribution of both species were compared with previous data from samples performed in the same area in 1985–1989. The aim of this research was to determine whether the densities of both species decreased; whether C.fluminea is still more abundant than C.largillierti; and whether the size frequency distributions indicate different population structures from those observed in the end of the 1980’s. Nine localities from the river shore were sampled, and each individual was identified and measured. The size of C.fluminea varied between 2 and 39 mm, showing the highest frequency of individuals between 20 and 25 mm; furthermore the density decreased 90% in 2015/2016. No specimens of C.largillierti were found. In conclusion, the populations of Corbicula inhabiting the Río de la Plata River are retracting.

Highlights

The Asiatic clam, Corbicula fluminea (Müller, 1774) naturally inhabits freshwater bodies from Southeast Asia, Africa, India, Pacific Islands and Australia (McMahon 1983, 2000)
In South America, two species of Corbicula Megerle, 1811, C. fluminea and C. largillierti (Philippi, 1844), arrived in the Río de la Plata River in the 1970’s, according to Ituarte (1981), who mentioned the presence of Corbicula sp. for the first time in South
Corbicula fluminea was present in seven sampling sites (Table 1)

Summary

Introduction

The Asiatic clam, Corbicula fluminea (Müller, 1774) naturally inhabits freshwater bodies from Southeast Asia, Africa, India, Pacific Islands and Australia (McMahon 1983, 2000). This species arrived in North America in 1920 (McMahon 2000) causing important environmental and economic problems, which resulted from its ability to reproduce quickly, and its capacity to adapt to different ecological conditions (Britton and Morton 1979, McMahon 1983). Veitenheimer-Mendes and Olazarry (1983) provided new records from the Uruguay River (34°02’S, 58°15’W), Uruguay (Colonia Department) and in the Río de la Plata River (34°27’S, 57°15’W), Uruguay (San José Department)

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