Effects of mercury exposure on ionic regulation in the crayfish Orconectes propinquus

• Published in: Environmental pollution (1987) 1993, Vol.82 (2), p.139-142
• Main Authors: Wright, D.A., Welbourn, P.M.
• Format: Article
• Language: English
• Subjects: Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on protozoa and invertebrates; Fundamental and applied biological sciences. Psychology; Invertebrates
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/0269-7491(93)90110-A

Hemolymph sodium, potassium and calcium concentrations were determined in crayfish (Orconectes propinquus) exposed to 203HgCl 2 mixed with food to a concentration of 1 μg Hg g −1. Dummy-fed animals were exposed to Hg-dosed food wrapped in dialysis tubing to control for mercury reaching the animals via leaching from food to water. Hemolymph analyses were made following 14-day Hg exposures and again after a further 21-day ‘depuration’ period during which all animals were fed Hg-free food. After 14 days, the mercury reached a concentration of 0·175 μg g −1 in the hepatopancreas and approximately half this level in the gills of Hg-fed animals. No depuration occurred from the hepatopancreas although the gills lost approximately two-thirds of their labelled mercury during the depuration period. Hemolymph sodium concentrations in Hg-exposed crayfish, both fed and dummy-fed, after 14 days were significantly lower than in Hg-free controls and remained low following the 21-day depuration period. Hemolymph calcium concentrations were lower in Hg-fed animals than in dummy-fed and control animals after 14 days although calcium levels rose in all treatments after 35 days. This may have been due to the incidence of pre-molt animals in all experimental groups, although the relationship between this and mercury exposure was not established unequivocally. Hemolymph potassium levels showed no differences between treatments.