Short- and long-term exposure of Lumbriculus variegatus (Oligochaete) to metal lead: ecotoxicological and behavioral effects

Abstract

Metals are naturally occurring constituents of the environment and although many are essential nutrients for living organisms, at higher concentrations they can be toxic. Some aquatic species can help understand and even predict the impact of those contaminants. Lumbriculus variegatus is a recommended species for use in sediment toxicity tests and is known to have a remarkable ability of segmental regeneration. Short- (10-day) and long-term (28-day) toxicity tests were used to test theeffectsofametalonthesurvival,growth,andbehaviorofL.variegatus.Thiswork aims to investigate and validate the use of behavior as a new parameter in standard toxicitytests.Wormswereexposedtosedimentscontaminatedwithdifferentlevelsof lead and the results indicated a positive relation between lead concentrations and mortalityandgrowth:higherleadconcentrationsresultedinhighermortalitiesand strong inhibition of growth. An inhibition of behavior was observed and results suggested that although behavior could not be used in sediment toxicity tests, it proved useful as an addition to short-term tests and helps select sediments. Thus, exposure to sediments contaminated with lead affects the presence of this species in nature, because it interferes with growth and survival.