Population dynamics of the brine shrimp Artemia persimilis Piccinelli &amp; Prosdocimi, 1968 (Crustacea, Anostraca) in a hypersaline lake of the Central Pampa (Argentina)

Alicia M Vignatti,Santiago A Echaniz,Gabriela C Cabrera

doi:10.1590/1676-0611-bn-2017-0353

Abstract

Abstract The anostracan Artemia is one of the few organisms that can inhabit hypersaline lakes. In Argentina, this genus is represented by two species: the invasive A. franciscana Kellogg, 1906 and the autochthonous A. persimilis Piccinelli & Prosdocimi, 1968, the latter being the only one recorded in the province of La Pampa. Some of the biological aspects of A. persimilis are known based on laboratory studies, and data on its ecology in natural conditions are scarce. The aim of this work is to present information on the density, biomass, and population structure of A. persimilis in relation to environmental variables in Utracán, a hypersaline lake of the semiarid Central Pampa of Argentina. Water and zooplankton samples were taken monthly from May 2009 until August 2010. The mean density and biomass were 56.98 ind.L-1 (± 106.64) and 1.23 mg.L-1 (± 1.35), respectively. The species was negatively affected by salinity, and it was absent between November and February, when salinity exceeded 320 g.L-1. However, when it was present, even during the months of higher salinity, a high proportion of naupliar stages was found, which could indicate that, in nature, A. persimilis can reproduce with high salinity. Although it has been indicated that A. persimilis could be displaced by A. franciscana, the highest tolerance of the former at low temperatures, which allowed the population to continue reproducing at values close to 3°C, would limit its displacement. However, an increase in the temperature of lakes as a result of global warming could modify this situation and allow the advance of the introduced species to the south.

Highlights

IntroductionThe anostracan Artemia is one of the few organisms that can inhabit hypersaline lakes (total dissolved solids > 50 g.L-1) because it has physiological mechanisms to withstand osmotic stress (Gajardo & Beardmore 2012)
The anostracan Artemia is one of the few organisms that can inhabit hypersaline lakes because it has physiological mechanisms to withstand osmotic stress (Gajardo & Beardmore 2012)
It has been indicated that A. persimilis could be displaced by A. franciscana, the highest tolerance of the former at low temperatures, which allowed the population to continue reproducing at values close to 3°C, would limit its displacement

Summary

Introduction

The anostracan Artemia is one of the few organisms that can inhabit hypersaline lakes (total dissolved solids > 50 g.L-1) because it has physiological mechanisms to withstand osmotic stress (Gajardo & Beardmore 2012). A. persimilis is autochthonous, restricted to environments in Chile and Argentina (Clegg & Gajardo 2009), and at present is the only species recorded in the province of La Pampa (Vignatti et al 2014, Echaniz et al 2015) The species of this genus have economic importance, since from the naupliar stage until adulthood they are used as live food in the breeding of several fish and crustaceans of commercial value, because they constitute a source of proteins, lipids, essential amino acids, and unsaturated fatty acids beneficial to the organisms in culture (Dhont & Lavens 1996, Dhont & Sorgeloos 2002). Increasing knowledge about the biology of the species is an important aspect, as its geographical distribution could be in decline, because it has been proven that A. franciscana tends to displace native species of the places it colonizes (Green et al 2005) due to its higher phenotypic plasticity (Browne & Wanigasekera 2000, Clegg & Gajardo 2009, Vikas et al 2012)

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