Presence of Palaemon macrodactylus Rathbun 1902 (Crustacea: Decapoda: Caridea: Palaemonidae) in Quequén river

VÁZQUEZ MARÍA GUADALUPE; BAS CLAUDIA

Ciudad Autónoma de Buenos Aires

Congreso; Marine & Freshwater Invasive Species: Ecology, Impact, and Management (MFIS) conference scientific; 2016

Aquatic Ecosystem health and management sociaty, Conicet

Palaemon macrodactylus (oriental shrimp), native to estuarine waters of Southeast Asia, has been recorded outside of its origin range in the waters of USA, Australia, Europe and Argentina. The first record in Argentina was in the Mar del Plata harbor and years later it was found in estuarine areas: Bahía Samborombón, Bahía Blanca and Río Negro mouth. In this work we report the first sightings of P. macrodactylus in the Quequén harbor and the subsequent colonization of Quequén river. On 19 January 2008 11 males and 13 females (3 ovigerous) were collected in Quequén harbor, at the mouth of the Quequén river, where marine conditions prevail (salinity 32 psu) but no individuals were found in the riverine zone. Only in January 2016 several individuals were found in the river at 2,5 km from the mouth. A sampling program was then performed in February 2016 from 2 to 9 km upstream. Numerous individuals were collected up to 6 km from the mouth, at salinities ranging between 2-17 psu, at high tide. The adults of P. macrodactylus showed the diagnostic characters stated by Rathbun (1902) and Newman (1963). A total of 30 males, 31 females (5 ovigerous) and 2 juveniles were collected. The maximum carapace lengths were 6.41mm for males and 7.86 mm for females. The finding of ovigerous females and juveniles suggest a stable population. The absence of shrimps upstream (more than 6 km from the mouth) may respond to the presence of waterfalls that probably act as natural barriers for shrimp. We deposited voucher specimens in the MACN with the accession numbers MACN-In 40404.