Effects Of Heptachlor and Toxaphene on Laboratory-Reared Embryos and Fry of the Sheepshead Minnow
Flow-through seawater bioassays of 28-days duration were conducted with the organochlorine pesticides heptachlor and toxaphene to detennine their toxicity to and bioconcentration by embryos and fry of the sheepshead minnow (Cyprinodon variegatus). At technical heptachlor measured concentrations of 4.3, 3.5, 2.2, 2.0, and 1.2 u/1 (ppb), test animal survival was 1, 5, 61, 79, and 88%, respectively. At toxaphene measured concentrations of 2.5, 1.1, 0.6, 0.3, and 0.2 1u/1, test animal survival was 10, 85, 79, 88, and 80% respectively. Average standard length of fry continuously exposed from...
