Trimethylarsine oxide in estuary catfish (Cnidoglanis macrocephalus) and school whiting (Sillago bassensis) after oral administration of sodium arsenate; and as a natural component of estuary catfish.

Oral administration of sodium arsenate to estuary catfish (Cnidoglanis macrocephalus) and school whiting (Sillago bassensis) resulted in an accumulation of trimethylarsine oxide in their tissues. The levels of arsenobetaine, which occurs naturally in these fish, did not appear to be affected by the oral dosing with sodium arsenate. Trimethylarsine oxide also occurred as a natural component of estuary catfish and its presence may be related to the mode of feeding of this fish.