Acute and chronic effects of sodium and potassium on the tropical freshwater cladoceran Pseudosida ramosa

Abstract

In this study, the toxicities of sodium and potassium to the tropical freshwater cladoceran Pseudosida ramosa were assessed. Acute toxicity tests on this species showed that the 48-h LC(50) of Na(+) was 556 mg l(-1), while that of K(+) was 17.7 mg l(-1). Long-term exposure of female P. ramosa to sodium reduced the total number of survivors from 10 to 6 at a concentration of 249 mg l(-1), 21-day fecundity from 20.4 to 14.3 eggs female(-1) at concentrations ranging from 72 to 249 mg l(-1), 21-day fertility from 20.1 to 6.5 neonates female(-1) at concentrations ranging from 25 to 249 mg l(-1). Furthermore, fecundity of each brood from the second to the fifth was significantly lower at 249 mg l(-1) and fertility of each brood from the first to the fifth at concentrations ranging from 25 to 249 mg l(-1). A significant decrease in fertility was associated with an increase in the number of aborted eggs. Long-term exposure to potassium decreased the 21-day fecundity of P. ramosa from 14.2 to 10.8 eggs female(-1) at a concentration of 11 mg l(-1) and fertility (fourth brood only) at 6.2 and 11 mg l(-1). Tropical reservoirs located near areas where the soil is overloaded with fertilizers and ferti-irrigation with vinasse already show concentrations of Na(+) and K(+) very close to those producing sub-lethal long-term effects on P. ramosa. A possible consequence is that organisms of the aquatic biota cannot adapt and freshwater taxa may become locally extinct, transferring dominance to salt-tolerant taxa.

Multiple riparian–stream connections are predicted to change in response to salinization

“…death and colonization (detrital quality (3)) consumption (13) c ( 6 ) e m e r g e n c e ( 7 ) u p ta k e ( 8 ) l i t t e r f a l l ( 9 ) Figure 1. Riparian -stream interactions that could be altered by salt additions.…”

The effects of CaCl2 and CaBr2 on the reproduction of Daphnia magna Straus / Učinak CaCl2 i CaBr2 na razmnožavanje vodenbuhe (Daphnia magna Straus)

“…NaBr and 3,4-dichloroaniline (29), ibuprofen (30), and insecticides (31). An increased number of aborted eggs and a reduction in the number of hatched individuals have been documented in NaCl solutions at concentrations of Na ranging from 25 to 249 mg L -1 Na + and 41 to 249 mg L -1 Na + , respectively, in chronic exposure of the freshwater cladoceran Pseudosida ramosa (32,33). Baird et al (29) reported that the chronic inhibition of reproduction in D. magna at 3 to 17 mg L -1 NaBr was due solely to the acute lethal effect on eggs developing in the brood chamber.…”

Distribution and biological aspects of the introduced speciesMoina macrocopa (Straus, 1820) (Crustacea, Cladocera) in the semi-arid central region of Argentina

“…However, in La Pampa, this species has been recorded in water bodies with a wide range of salinity of up to approximately 22 g.L -1 (Hammer 1986). Anthropic eutrophication, which is due to the input of an excess of nutrients (phosphorus and nitrogen) into any water body, can come from three sources: industrial, domestic or agricultural (Freitas & Rocha 2011). In other parts of the world, M. macrocopa is often associated with hypertrophic or eutrophic environments with high anthropogenic influence, especially those under the influence of cities; for example, sewage treatment basins or rivers with strong domestic organic pollution, such as the Mula River in India (Vanjare et al 2010), or those impacted by industrial activities, such as lakes for paper-making industry sewage treatment (Espinosa-Chávez et al 1992, Martínez & Gutiérrez 1997, Benider et al 1998.…”