I stopped breeding cribos a few years ago. Up until that point none of my blacktail or yellowtail males ever fasted. When they reached breeding age, they were bred.
For the last few years, I have noted that my sexually mature males go off feed from the beginning to middle of December to the middle to end of January.
During this time, I have noted the following:
(1) The spend the majority of their time out in the open.
(2) Their shed cycle is rapidly sped up - from five/six weeks to three/four weeks. Oftentimes with a week between shedding and the first signs ecdysis (reddening of the ventral scales).
Starting in mid-January, the males lose their sperm plugs (usually in their water dishes). Days later, they are looking to feed.
So for four males, the averages are:
- average day off feed: December 6
- average day back on feed: January 22
- average shed cycle (regular): 40 days
- average shed cycle (fasting): 24 days
- average weight loss: 349 grams
- average starting weight: 4331 grams
This is with no changes in enclosure temperature, photo periods (artificial) or humidity.
I don't know if this will help anyone out there. Though at least a few might find it interesting.