Question:
My fish appears to have a very swollen abdomen. Could this be due to me overfeeding him?
Answer:
Siamese fighting fish (Bettas) originate from Thailand (hence “Siamese”) and this is a tropical country where temperatures would not normally drop to what we experience in Perth. It is true that during transporting (exporting/importing) of ornamental fish, the temperature is reduced slightly to decrease their metabolic rate, this is not usually tolerated for long periods. Fighting fish may “survive” one or two Perth winters, but will eventually succumb to disease/illness in unheated tanks during winter. The abdomen is swollen, most likely because the food ingested is not being digested, and is instead being fermented. Differential diagnoses include granulomatous reactions from Mycobacteria or Nocardia infections or problems with fluid balance, usually associated with bacterial nephritis. My advise would be to cease feeding for 1 week and in this time, slowly raise the temperature to 26degC.
