Developmental abnormalities in horseshoe crab embryos caused by exposure to heavy metals

• Published in: Archives of environmental contamination and toxicology Vol. 35; no. 1; pp. 33 - 40
• Main Authors: ITOW, T, LOVELAND, R. E, BOTTON, M. L
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer-Verlag 01-07-1998; Berlin Springer Nature B.V; New York, NY
• Subjects: Animal, plant and microbial ecology; Applied ecology; Bioassays; Biological and medical sciences; Crustaceans; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on protozoa and invertebrates; Embryos; Fundamental and applied biological sciences. Psychology; Heavy metals; Limulus polyphemus; Mercury; Metals; Spawning; South China Sea; United States; Inland Sea; America; North America; West Atlantic; New Jersey; Gulf of Siam; ANW, USA, Delaware Bay; ANW, USA, New Jersey, Sandy Hook Bay; Embryonic development; Embryo; Toxicity; Biological indicator; Heavy metal; Marine environment; Pollutant; Malformation; Arthropoda; Merostomata; Water pollution; Invertebrata; Limulus polyphemus
• ISSN: 0090-4341; 1432-0703
• DOI: 10.1007/s002449900345

We examined the effects of heavy metals on the development of horseshoe crabs using bioassays in which embryos at different stages were exposed either continuously or for 24 h. Abnormalities included segment-defective embryos, double embryos, embryos with abnormal eye areas, and no-posterior embryos. In terms of their ability to affect normal development, the pollutants are ranked as follows: Hg >== organotin > Cr falling dots Cd > Cu > Pb > Zn. Organotin treatment was associated with a high frequency of abnormal eye embryos and Hg with segment-defective embryos. The specific cause of segment-defective malformations by Hg was investigated by using SH inhibitors and cytochalasin B, an inhibitor of microfilaments. These inhibitors induced Hg-type segment-defective embryos; thus, Hg may also act by inhibiting SH-SS exchange and blocking morphogenetic movements. Horseshoe crab embryos from Delaware Bay and Sandy Hook Bay, New Jersey, were examined for developmental abnormalities. Malformed embryos were extremely rare (<0.6%) at five beaches along Delaware Bay as well as Sandy Hook Bay, suggesting that these horseshoe crab spawning areas are relatively unpolluted by heavy metals.