STP634

    An Evaluation of Fenitrothion Toxicity in Four Life Stages of Rainbow Trout, Salmo gairdneri

    Published: Jan 1977


      Format Pages Price  
    PDF Version (168K) 10 $25   ADD TO CART
    Complete Source PDF (4.6M) 10 $55   ADD TO CART


    Abstract

    Lethal and sublethal effects of fenitrothion, an organophosphate insecticide, were investigated in rainbow trout (Salmo gairdneri) embryos, sac fry, fingerlings, and adults. Embryos first exhibited cholinesterase activity 14 days before hatch. Embryos and sac fry at various ages subjected to 34 mg/litre fenitrothion for 24 h under static exposure conditions first exhibited mortality 6 days after hatch. A 24-h lethal concentration of 50 percent of organisms (LC50) of 3.4 mg/litre and a 96-h LC50 of 2.0 mg/litre were obtained using fingerlings exposed to fenitrothion in a flow-through system. Fingerlings surviving 96 h of exposure exhibited cholinesterase activities ranging from 13 to 25 percent of controls (brain) and 30 to 51 percent (skeletal muscle). Adult trout were monitored for electrocardiogram and respiratory responses to fenitrothion concentrations of 5.0, 1.0, and 0.5 mg/litre. At 5 mg/litre, heart rate decreased initially but recovered within 24 h. Cough frequency was directly related to fenitrothion concentration. Based on acute mortality tests, the embryological life stage was the least sensitive, the sac fry stage was intermediate, and the life stages of fingerlings and adults were the most sensitive. The sublethal responses, cholinesterase inhibition in fingerlings and the cough response in adult trout, were sensitive to 0.75 and 0.5 mg/litre fenitrothion.

    Keywords:

    water analysis, toxicology, fenitrothion, organic phosphates, rainbow trout, embryos, sac fry, fingerling, adults, cholinesterase, cough frequency, electrocardiograms


    Author Information:

    Klaverkamp, JF
    Research scientist and biologists, Environment Canada, Fisheries and Marine, Freshwater Institute, Winnipeg, Man.

    Duangsawasdi, M
    Predoctoral trainee, University of Manitoba, Winnipeg, Man.

    Macdonald, WA
    Research scientist and biologists, Environment Canada, Fisheries and Marine, Freshwater Institute, Winnipeg, Man.

    Majewski, HS
    Research scientist and biologists, Environment Canada, Fisheries and Marine, Freshwater Institute, Winnipeg, Man.


    Paper ID: STP32402S

    Committee/Subcommittee: E35.30

    DOI: 10.1520/STP32402S


    CrossRef ASTM International is a member of CrossRef.