Colony Formation in Three Species of the Family Scenedesmaceae (Desmodesmus subspicatus, Scenedesmus Acutus, Tetradesmus Dimorphus) Exposed to Sodium Dodecyl Sulfate and its Interference with Grazing of DAPHNIA Galeata.

Yusuke Oda,Yuichi Miyabara,Masaki Sakamoto

doi:10.1007/s00244-021-00890-8

Abstract

By mimicking the info-chemicals emitted by grazers, the common anionic surfactant sodium dodecyl sulfate (SDS) can induce colony formation in the green algal genus Scenedesmus at environmentally relevant concentrations. The morphometric effects can hinder the feeding efficiency of grazers, reducing energy flow along the pelagic food chain from Scenedesmus to consumers. Despite this potential ecological risk, few studies exist on whether the SDS-triggered induction of colonies is common in other species of the family Scenedesmaceae. Here, we investigated the effects of SDS on the growth and morphology of three species of Scenedesmaceae (Desmodesmus subspicatus, Scenedesmus acutus, and Tetradesmus dimorphus) and on the clearance rates of Daphnia galeata grazing on the SDS-induced colonies. SDS triggered colony formation in all algal species at concentrations nonlethal to them (0.1-10mg L-1) in 72h; however, the induction levels of colony formation were generally lower than for those in the Daphnia culture medium. We also found that the SDS-induced colonial algae reduced D. galeata clearance rates. Our results highlight the potential effect of SDS on the Daphnia-Scenedesmaceae system by triggering the morphological response of Scenedesmaceae at concentrations below those that exert toxicity. Such disruptive effects of pollutants on predator-prey interactions should be considered within the framework of ecological risk assessments.

Highlights

Sodium dodecyl sulfate (SDS) is a common anionic surfactant for various applications: industry, medical care, and household goods
The ratio test revealed that these EC50 values were significantly different (P < 0.05), indicating that sensitivity to sodium dodecyl sulfate (SDS) was as follows: D. subspicatus > T. dimorphus > S
The 72-h EC50 values of SDS for the three Scenedesmaceae species examined here ranged from 23.6 mg

Summary

Introduction

Sodium dodecyl sulfate (SDS) is a common anionic surfactant for various applications: industry (e.g., cleaning agents and auxiliary agents of pesticides), medical care (e.g., pharmaceuticals), and household goods (e.g., personal care products and cosmetics). Owing to its extensive consumption, SDS can contaminate aquatic systems through the direct discharge of sewage effluents or by soil leaching The toxicity of SDS to aquatic organisms has been investigated since the 1990s. 50% effective or lethal concentration (EC50 or LC50) of SDS to fishes, invertebrates (mainly cladoceran crustaceans), and algae was 7.3–48 mg L-1 (e.g., Arezon et al 2003; Hemmer et al 2010; Reátegui-Zirena et al 2013), 7.4–48 mg L-1 (e.g., Martinez-Jeronimo and Garcia-Gonzalez 1994; Bulus et al 1996; Shedd et al 1999), and 4.8–36.6 mg L-1 (Liwarska-Bizukojc et al 2005; Mariani et al 2006), respectively. Despite SDS being almost harmless to aquatic organisms, several studies have mentioned its potential effects on the aquatic community through the impairment of predator–prey interactions (Lürling and Beekman 2002; Yasumoto et al 2005; Zhu et al 2020).

Methods

Results

Conclusion