I was starting to give up hope on these
, but they are really tough fish!
Since I moved the Rio Ucayali out to the greenhouse in late 2022, I've had maybe 3-4 spawns (March 2023 (
HERE), 01 June 2023, 22 June 2023 and late August 2023). None of the March fry in the greenhouse tank were ever seen again (I presume they were killed by larger fish or just out-competed for food). When I found the summer spawns, I brought the eggs inside my lab and hatched them in breeder boxes. On each occasion, the hatch rates were poor with lots of eggs failing, but I always got some fry; however, in all three of those spawns, after a week or so of growth, all the fry would die slowly for no obvious reasons. I wondered if maybe the very hot summer conditions in the greenhouse harmed the eggs and reduced the health of the fry, even though the fry were hatched indoors.
Then in the Fall of 2023, when I moved some
out to the greenhouse tank with
Ancistrus sp. Rio Ucayali to build my group of mustard spots, a disease ravaged the tank (it's described elsewhere). I lost everything else in the tank (over 50
juveniles and over 25 juvenile
, and all but one of seven mustard spots)... but somehow five Rio Ucayali survived that disease.
Fast forward to Winter 2023, and on two separate occasions over the holiday break (about 18 December (reported
HERE) and again on 01 January), power was cut to the greenhouse for different reasons, each time while I was away for 3‐4 days.
On both occasions, the tank temperatures dropped to the low 40's Fahrenheit (4-7C) for days at a time. Throughout those two times, they lived at "outdoor winter" temperatures, with overnight low temperatures in the 40F range and daytime high temperatures in the 50F range.
These temperature drops killed the one remaining mustard spot and at least two Rio Ucayali, but miraculously one male and two female Rio Ucayali survived both of those traumas.
I made the difficult but obvious decision to close down the greenhouse tanks and I moved the Rio Ucayali inside to my lab. After warming them up slowly to indoor room temperature (73-74F) around 04 January, they spawned on 22 January, but the eggs were nonviable. Then a few weeks later on 05 February, they spawned again and this time the eggs hatched (about a week ago). Today on 17 February, those fry are doing well; with a little reservation, these fry are only about a week post-hatching, and that is when in recent spawns the fry started dying, so I have to watch these carefully, but so far they look good, and certainly the hatch rate was much better this time.
Also today, dad is on another new spawn! Hopefully we're back at it with these.
- 22 January spawn
- 05 February spawn
- 17 February spawn
Cheers, Eric