| low levels of sodium and potassium in the water from wetlands in minnesota that contained malformed frogs affect the rate of xenopus development. | water samples were collected between 1999 and 2000 from wetlands in minnesota that contained malformed frogs. the water samples were analyzed for 14 minerals/ions and screened for the presence of biologically active compounds using xenopus laevis. results indicated that water from two sites, cwb and roi2, induced severe retardation with embryo lengths reduced 20% after 96 hr of development. the developmental delay observed with water from roi2 was alleviated by supplementation with sodium, while ... | 2004 | 15887362 |