Foster L. Mayer

Interactions of Toxaphene and Vitamin C in Channel Catfish

Abstract The involvement of vitamin C as a cofactor in detoxication mechanisms of fish was investigated by feeding selected amounts of the vitamin in diets of fingerling channel catfish (Ictalurus punctatus) that were concurrently exposed to toxaphene, a widely used organochlorine insecticide in the Southeastern United States. Three groups of fish were exposed continuously to each of five toxaphene concentrations—37, 68, 106, 218, and 475 ng/liter—and fed a diet containing 63, 670, or 5,000 mg/kg of vitamin C. After 150 days of toxaphene exposure, backbone collagen was significantly decreased in most fish fed the diet containing 63 mg/kg of vitamin C. However, the toxaphene concentrations of 37 and 68 ng/liter did not cause this effect in fish fed the 670 mg/kg vitamin C diet, and only the 475 ng/liter concentration significantly depressed backbone collagen in fish fed the 5,000 mg/kg diet. Spinal deformities were common among fish fed low vitamin C diets, but the incidence decreased as dietary vitamin C ...

Relationship between Body Contaminants and Bone Development in East-Coast Striped Bass

Abstract Chemical contaminants and bone development were investigated in young-of-year striped bass collected in spring, summer, and fall from the Nanticoke, Potomac, and Hudson rivers and Edenton National Fish Hatchery, North Carolina. Polychlorinated biphenyls (PCB) were the most prevalent organic contaminants found in striped bass; relatively lesser amounts of DDT, DDD, DDE, and chlordane were detected. Among the four locations, striped bass from the Hudson River contained the greatest amount of PCB; concentrations significantly increased with collection date in fish from the Hudson and Potomac rivers. Total organochlorine residues in striped bass from the Edenton Hatchery and the Nanticoke River were less than those from the Hudson and Potomac rivers, and the contaminants did not increase significantly with collection date. Arsenic, lead, cadmium, and selenium were the major inorganic contaminants in striped bass in the Hudson, Nanticoke, and Potomac rivers. Cadmium in fish from the Hudson River, and ...

Acute and Chronic Effects of Kepone and Mirex on the Fathead Minnow

Abstract Acute and chronic toxicity studies were conducted with fathead minnows (Pimephales promelas) and the organochlorine insecticides Kepone and mirex. Kepone was highly toxic to fathead minnows under acute conditions; 96-hour LC50s (median lethal concentrations; 95% confidence limits in parentheses) were as low as 340 (289–400) μg/liter and 96-hour EC50s (median effective concentrations; 95% confidence limits in parentheses) were as low as 18 (15–22) μg/liter. The observed effect, upon which the EC50 calculations were based, was an extensive hemorrhage associated with an apparent fracture or dislocation of the vertebral column in the region of the dorsal fin. Mirex was not acutely toxic to fathead minnows, even at concentrations that exceeded its maximum water solubility. Chronic toxicity testing indicated that the maximum acceptable toxicant concentration for fathead minnows exposed to Kepone was between 1.2 and 3.1 μg/liter. Adverse chronic effects of mirex were limited to a possible impairment o...

Method to Evaluate Mechanical Properties of Bone in Fish

Abstract A method for testing the mechanical properties of fish vertebrae was adapted from other vertebrae studies and used to describe the structural integrity of fishes vertebra tissues. Individual vertebrae from the anterior region of the spinal column were subjected to compression tests to determine strength (ultimate stress and stress at elastic limit), elasticity (ultimate strain and modulus of elasticity), and energy-absorbing capacity (toughness). For brook trout Salvelinus fontinalis, channel catfish Ictalurus punctatus, and bluegills Lepomis macrochirus, mechanical properties of bone differed among species and changed with age within a species. Overall, changes in mechanical properties were related to age-dependent changes in bone density.

Waste Transformer Oil and PCB Toxicity to Rainbow Trout

Abstract Young rainbow trout Salmo gairdneri (starting age, 17 d) were exposed to nominal concentrations of 0, 0.38, 0.75, 1.5, 3.0, and 6.0 μg/L total polychlorinated biphenyls (PCBs) for 90 d, then held in fresh water for 60 d. Sources of PCBs were (1) waste transformer oil containing various hydrocarbons plus a 1:2 ratio of Aroclors 1254 and 1260, and (2) pure technical PCBs of the same Aroclor ratio as that in the transformer oil. Survival of fish was much lower in transformer oil than in technical PCBs at day 90. Growth was reduced at day 30 by the transformer oil, but not until day 90 at the highest concentration of technical PCBs. Fin erosion was severe and vertebra integrity was reduced in fish exposed to transformer oil but not in fish exposed to technical PCBs. Abnormal swimming behavior of fish exposed to transformer oil was attributed to reduced volume of the swim bladder. Exposures to transformer oil decreased hematocrit, and increased serum cortisol to twice that of controls and of fish expo...

Kepone and Mirex: Effects on Bone Development and Swim Bladder Composition in Fathead Minnows

Abstract The biochemical effects of Kepone and mirex on bone development and swim bladder composition in fathead minnows Pimephales promelas were investigated in chronic toxicity studies. Continuous exposure of fathead minnows to Kepone (0.013–0.31 μg/liter) or mirex (2–34 μg/liter 0 led to the alteration of collagen and vitamin C metabolism within 30 days. Kepone concentrations of 0.17 and 0.31 μg/liter reduced collagen metabolism in the backbone after 120 days of exposure. Both mirex (⩾3 μg/liter) and Kepone (⩾0.31 μg/liter) decreased hydroxyproline concentration in the swim bladder. Acute exposure of fathead minnows to Kepone did not affect the chemical composition of vertebrae, even though scoliosis and vertebral damage were observed. Thus Kepone can induce vertebral damage in two ways: Acutely, by causing muscular contractions; and chronically, by altering vertebral collagen metabolism.

Mechanical Properties of Bone in Channel Catfish as Affected by Vitamin C and Toxaphene

Abstract Channel catfish Ictalurus punctatus subjected to a diet deficient in vitamin C for 150 days showed a decrease in backbone collagen and hydroxyproline concentrations, whereas the mineral: Collagen ratio and bone density increased. These changes resulted in a 20% reduction in bone strength and a 46% increase in vertebral elasticity. The backbone of channel catfish exposed to the insecticide toxaphene for 90 days also had decreased collagen, but hydroxyproline concentration, mineral: Collagen ratio, and bone density all increased. These alterations in backbone composition resulted in a 34% increase in strength and a 39% decrease in vertebral elasticity. In both experiments, hydroxyproline concentrations in backbone collagen had the greatest influence on the structural properties of vertebrae, whereas collagen, calcium, and phosphorus concentrations did not. Mechanical properties seemed to be more sensitive indicators of vertebral structural integrity than did biochemical ones or bone density.