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.

Toxicity of heavy metals using sperm cell and embryo toxicity bioassays withParacentrotus lividus(Echinodermata: Echinoidea): Comparisons with exposure concentrations in the Lagoon of Venice, Italy

“…For Hg 2+ , increasing concentrations caused a linear increase in both malformed plutei and blastula and gastrula stages from 0.02 mg/L. Our data are in agreement with Warnau et al [17], who observed a shift from severe skeletal malformations to the arrest of differentiation at blastula and gastrula stages from 0.02 to 0.06 mg/L, with a higher embryotoxic effect at the latter concentration (dead embryos). Other authors found pre‐pluteus stages and morulae at 0.016 and 0.032 mg/L, respectively [22].…”

“…However, our data are in agreement with the EC50 value (0.5 mg/L) obtained with Strongylocentrotus purpuratus using a very comparable methodology [14]. According to the literature, the results show the higher sensitivity of embryo toxicity, explained by the capacity of Cd 2+ to influence skeletal differentiation [16,17].…”

“…The Cu 2+ showed a different trend, with a decrease in malformed plutei and an increase in prisms at about 0.072 mg/L and at the blastula and gastrula stages at 0.048 mg/L. Our data fit those of Warnau et al [17], who observed for Cu 2+ , like Hg 2+ , a shift from skeletal malformations to the arrest of differentiation at blastula and gastrula stages from 0.032 mg/L. Other authors found that embryo development was arrested at the gastrula stage at 0.064 mg/L [22] and did not reach the pluteus stage from 0.05 mg/L to 0.1 mg/L [23].…”

Toxicity of heavy metals using sperm cell and embryo toxicity bioassays withParacentrotus lividus(Echinodermata: Echinoidea): Comparisons with exposure concentrations in the Lagoon of Venice, Italy

“…For Hg 2+ , increasing concentrations caused a linear increase in both malformed plutei and blastula and gastrula stages from 0.02 mg/L. Our data are in agreement with Warnau et al [17], who observed a shift from severe skeletal malformations to the arrest of differentiation at blastula and gastrula stages from 0.02 to 0.06 mg/L, with a higher embryotoxic effect at the latter concentration (dead embryos). Other authors found pre‐pluteus stages and morulae at 0.016 and 0.032 mg/L, respectively [22].…”

“…However, our data are in agreement with the EC50 value (0.5 mg/L) obtained with Strongylocentrotus purpuratus using a very comparable methodology [14]. According to the literature, the results show the higher sensitivity of embryo toxicity, explained by the capacity of Cd 2+ to influence skeletal differentiation [16,17].…”

“…The Cu 2+ showed a different trend, with a decrease in malformed plutei and an increase in prisms at about 0.072 mg/L and at the blastula and gastrula stages at 0.048 mg/L. Our data fit those of Warnau et al [17], who observed for Cu 2+ , like Hg 2+ , a shift from skeletal malformations to the arrest of differentiation at blastula and gastrula stages from 0.032 mg/L. Other authors found that embryo development was arrested at the gastrula stage at 0.064 mg/L [22] and did not reach the pluteus stage from 0.05 mg/L to 0.1 mg/L [23].…”

Toxicity of Hg, Cu and Zn on early developmental stages of the European clam (Ruditapes decussatus) with potential application in marine water quality assessment

“…These findings were consistent with the data previously reported for embryos and larvae of other marine invertebrates used in bioassays, such as sea urchins (Dinnel et al 1989;Warnau et al 1996). In our case, metal pre-exposure did not decrease the fertilisation ability of R. decussatus sperms except for Zn and Hg at the highest concentrations (respectively, 512 and 256 μg/l).…”

Toxic effects of copper and cadmium on fertilization potency of gametes of Pacific oyster (Crassostrea gigas)

“…The results are in good agreement with existing data on EC 50 values of embryotoxicity assays of those metals in other marine invertebrate species. 2,15 The results confirm previous studies 11 demonstrating that Pacific oyster embryos were more sensitive than sperm or oocytes to pollutant exposure. Gametes and embryos were relatively resistant to Cd toxicity compare to Cu.…”

Toxicity of heavy metals using sperm cell and embryo toxicity bioassays withParacentrotus lividus(Echinodermata: Echinoidea): Comparisons with exposure concentrations in the Lagoon of Venice, Italy

“…For Hg 2+ , increasing concentrations caused a linear increase in both malformed plutei and blastula and gastrula stages from 0.02 mg/L. Our data are in agreement with Warnau et al [17], who observed a shift from severe skeletal malformations to the arrest of differentiation at blastula and gastrula stages from 0.02 to 0.06 mg/L, with a higher embryotoxic effect at the latter concentration (dead embryos). Other authors found pre‐pluteus stages and morulae at 0.016 and 0.032 mg/L, respectively [22].…”

“…However, our data are in agreement with the EC50 value (0.5 mg/L) obtained with Strongylocentrotus purpuratus using a very comparable methodology [14]. According to the literature, the results show the higher sensitivity of embryo toxicity, explained by the capacity of Cd 2+ to influence skeletal differentiation [16,17].…”

“…The Cu 2+ showed a different trend, with a decrease in malformed plutei and an increase in prisms at about 0.072 mg/L and at the blastula and gastrula stages at 0.048 mg/L. Our data fit those of Warnau et al [17], who observed for Cu 2+ , like Hg 2+ , a shift from skeletal malformations to the arrest of differentiation at blastula and gastrula stages from 0.032 mg/L. Other authors found that embryo development was arrested at the gastrula stage at 0.064 mg/L [22] and did not reach the pluteus stage from 0.05 mg/L to 0.1 mg/L [23].…”

Toxicity of Hg, Cu and Zn on early developmental stages of the European clam (Ruditapes decussatus) with potential application in marine water quality assessment

“…These findings were consistent with the data previously reported for embryos and larvae of other marine invertebrates used in bioassays, such as sea urchins (Dinnel et al 1989;Warnau et al 1996). In our case, metal pre-exposure did not decrease the fertilisation ability of R. decussatus sperms except for Zn and Hg at the highest concentrations (respectively, 512 and 256 μg/l).…”

Toxic effects of copper and cadmium on fertilization potency of gametes of Pacific oyster (Crassostrea gigas)

“…The results are in good agreement with existing data on EC 50 values of embryotoxicity assays of those metals in other marine invertebrate species. 2,15 The results confirm previous studies 11 demonstrating that Pacific oyster embryos were more sensitive than sperm or oocytes to pollutant exposure. Gametes and embryos were relatively resistant to Cd toxicity compare to Cu.…”

Toxicity of heavy metals using sperm cell and embryo toxicity bioassays withParacentrotus lividus(Echinodermata: Echinoidea): Comparisons with exposure concentrations in the Lagoon of Venice, Italy

“…For Hg 2+ , increasing concentrations caused a linear increase in both malformed plutei and blastula and gastrula stages from 0.02 mg/L. Our data are in agreement with Warnau et al [17], who observed a shift from severe skeletal malformations to the arrest of differentiation at blastula and gastrula stages from 0.02 to 0.06 mg/L, with a higher embryotoxic effect at the latter concentration (dead embryos). Other authors found pre‐pluteus stages and morulae at 0.016 and 0.032 mg/L, respectively [22].…”

“…However, our data are in agreement with the EC50 value (0.5 mg/L) obtained with Strongylocentrotus purpuratus using a very comparable methodology [14]. According to the literature, the results show the higher sensitivity of embryo toxicity, explained by the capacity of Cd 2+ to influence skeletal differentiation [16,17].…”

“…The Cu 2+ showed a different trend, with a decrease in malformed plutei and an increase in prisms at about 0.072 mg/L and at the blastula and gastrula stages at 0.048 mg/L. Our data fit those of Warnau et al [17], who observed for Cu 2+ , like Hg 2+ , a shift from skeletal malformations to the arrest of differentiation at blastula and gastrula stages from 0.032 mg/L. Other authors found that embryo development was arrested at the gastrula stage at 0.064 mg/L [22] and did not reach the pluteus stage from 0.05 mg/L to 0.1 mg/L [23].…”

Toxicity of Hg, Cu and Zn on early developmental stages of the European clam (Ruditapes decussatus) with potential application in marine water quality assessment

“…These findings were consistent with the data previously reported for embryos and larvae of other marine invertebrates used in bioassays, such as sea urchins (Dinnel et al 1989;Warnau et al 1996). In our case, metal pre-exposure did not decrease the fertilisation ability of R. decussatus sperms except for Zn and Hg at the highest concentrations (respectively, 512 and 256 μg/l).…”

Toxic effects of copper and cadmium on fertilization potency of gametes of Pacific oyster (Crassostrea gigas)

“…The results are in good agreement with existing data on EC 50 values of embryotoxicity assays of those metals in other marine invertebrate species. 2,15 The results confirm previous studies 11 demonstrating that Pacific oyster embryos were more sensitive than sperm or oocytes to pollutant exposure. Gametes and embryos were relatively resistant to Cd toxicity compare to Cu.…”