Spermiotoxicity and Embryotoxicity of Heavy Metals in the Echinoid Paracentrotus Lividus

Abstract

Abstract-Spermio-and embryotoxicities of Cu, Ag, Cd, and Hg were investigated in Paracentrotus lividus, the dominant echinoid species of the Mediterranean. Spermiotoxicity was studied by assessing the effects of sperm exposure on fertilization rate (FR) as well as on the induction of transmissible damages to the offspring. Embryotoxicity was studied by assessing developmental defects in larvae exposed to the tested metals throughout their development. Sperm exposures resulted in significant decreases of FR, depending on both metal concentration and duration of the exposure. Lowest spermiotoxic concentrations recorded when sperm were exposed for 75 min to the metals were 10 Ϫ7 M Hg(II), 10 Ϫ6 M Ag(I), 10 Ϫ5 M Cu(II), and 10 Ϫ5 M Cd(II). Tested metals did not exert any transmissible damage to spermatozoa that could result in larval malformations in the offspring, even for concentrations that dramatically reduced FR. Single-element exposures of embryos for 72 h resulted in developmental defects whose occurrence and severity showed a steep dose dependence, indicating that once a threshold is reached, any further increase in toxicant concentration rapidly enhances the impairment of target function(s). Those observations suggest the involvement of a saturable protective mechanism. Lowest observed embryotoxic concentrations of the metals were 10 Ϫ7 M Hg(II), 2.5 ϫ 10 Ϫ7 M Ag(I), 5 ϫ 10 Ϫ7 M Cu(II), and 10 Ϫ5 M Cd(II) and are in the range of concentrations reported in heavily polluted marine environments. Thus, the possibility of impairment of echinoid development actually exists in metal-contaminated marine environments, possibly threatening echinoid populations in those environments.

The effects of metals on embryo-larval and adult life stages of the sea urchin, Diadema antillarum

“…The EC50 of 11 g/L Cu measured in this study is at the low end of the range (11-120 g/L Cu) of reported EC50s for other species of sea urchin larvae (Kobayashi, 1977(Kobayashi, , 1980(Kobayashi, , 1981(Kobayashi, , 1994Rumbold and Snedaker, 1997;Phillips et al, 2003). D. antillarum larvae were also very sensitive to Ag with an EC50 below the range (14-100 g/L) of EC50s reported for other urchins (Dinnel et al, 1982(Dinnel et al, , 1983(Dinnel et al, , 1989Warnau et al, 1996). Current U.S. EPA Ambient Water Quality Criteria (AWQC) for Cu and proposed AWQC for Ag in marine systems are 3.1 and 2.9 g/L, respectively (U.S. EPA, 1980EPA, , 2003.…”

Cadmium, lead and their mixtures with copper: Paracentrotus lividus embryotoxicity assessment, prediction, and offspring quality evaluation

“…For the two non essential heavy metals, Cd and Pb, the EC50 value ranges reported in literature for P. lividus was 3400-11300 lg/l (Fernandez and Beiras 2001;Warnau et al 1996) and 414-680 lg/l (Novelli et al 2003), respectively.…”

Bioaccumulation of PCBs in the sea urchin Paracentrotus lividus: seawater and food exposures to a 14C-radiolabelled congener (PCB#153)

“…Its value as bioindicator species for metal contamination is well documented by numerous laboratory and field studies (e.g. Warnau et al 1995Warnau et al , 1996aWarnau et al ,b, 1998. Several studies have investigated the toxicological effects of PCBs on sea urchin early development (e.g.…”