I have had this little gunmetal male delta for seven months, during which time he's been eating enthusiastically and behaving energetically. He's grown quite a bit.
Over the last week or so, he's been eating gradually less and less, and for the last three days he hasn't eaten anything. He has always been a fussy eater who totally ignores pellets and dried food but seems to thrive and gain weight on frozen bloodworms.
Nothing I can see has changed in his environment or parameters: 0/0/0, 80*, lots of floating live plants plus Anubias and mossball in his 2.5gallon, which I change >50% twice/week. He seems a little laid back lately but no obvious indications of distress or abnormal behavior.
I promised I wouldn't worry until next year, but you know how it is. What do you suppose this might be?
Thanks for your consideration.