BaselineEssential, trace and toxic element concentrations in the liver of the world's largest bony fish, the ocean sunfish (Mola mola)

- Documented concentrations of 21 elements in the liver of an ocean sunfish.
- Toxic element concentrations were generally low compared to essential elements.
- Ca and Fe concentrations were elevated and suggestive of Ca and Fe toxicity.
- Cd was the highest of the toxic elements and ranked 8th among all elements.

No studies document essential (calcium, magnesium, phosphorus, potassium, sodium), trace (barium, boron, chromium, cobalt, copper, iron, manganese, molybdenum, selenium, zinc) or toxic element (antimony, arsenic, cadmium, lead, mercury, thallium) concentrations in any members of the family Molidae, including the world's largest bony fish, the ocean sunfish (Mola mola). Here, we analyzed 21 elements in the liver of one M. mola. These values were compared to liver concentrations in multiple species with spatial and dietary overlap. Concentrations of calcium (3339 ppm wet weight) and iron (2311 ppm wet weight) were extremely elevated in comparison to a number of other fish species, indicating that calcium and/or iron toxicity may have occurred in this animal. Concentrations of toxic elements were generally low, with the exception of cadmium (3.5 ppm). This study represents the first report of essential, trace and toxic elements in this species.