The onset of goiter in several species of sharks following the addition of ozone to a touch pool.
This report describes the onset of goiter in several species of shark following the addition of ozone to a touch pool. A detailed description of a female brown-banded bamboo shark (Chiloscyllium punctatum) that was presented with multinodular goiter is provided. Four other brown-banded bamboo sharks and 11 white-spotted bamboo sharks (Chiloscyllium plagiosum) housed in the same system developed clinical disease consistent with goiter, but two zebra bullhead sharks (Heterodontus zebra) did not. Plasma thyroxine (T4) concentration was 4.64 ng/ml before euthanasia, consistent with a diagnosis of hypothyroidism. The sharks had been chronically exposed to mean (+/- standard error) NO3-N concentrations of 35 +/- 5.12 mg/L before ozonation of the system. Ozonation of aquarium water causes a reduction in environmental iodide, which is required for thyroid hormone synthesis. Nitrate is goitrogenic and would further decrease I- absorption by competitive inhibition. Multinodular goiter is consistent with goiter caused by chronic iodide deficiency. Understanding the interaction between water chemistry and goiter development is critical to development of elasmobranch health management systems.
Department of Biology, University of North Carolina at Greensboro, 312 Eberhart Building, Greensboro, North Carolina 27402, USA. almorri7@uncg.edu
Alexis L
AL
Morris
Donald W
DW
Stremme
Barbara J
BJ
Sheppard
Michael T
MT
Walsh
Lisa L
LL
Farina
Ruth
R
Francis-Floyd
D000818:Animals; D000836:Animals, Zoo; D005260:Female; D005393:Fish Diseases / Q000139:chemically induced*; D006042:Goiter / Q000139:chemically induced / Q000188:drug therapy / Q000473:pathology / Q000662:veterinary*; D007454:Iodides / Q000737:chemistry; D007455:Iodine / Q000172:deficiency / Q000627:therapeutic use; D009566:Nitrates / Q000737:chemistry; D010126:Ozone / Q000009:adverse effects* / Q000737:chemistry; D012623:Seawater / Q000737:chemistry; D012754:Sharks
D007454:Iodides; D009566:Nitrates; D010126:Ozone; D007455:Iodine