I apologize in advance for such a long post . I do not mean to hijack your thread.
The fish in my pics are not fry, they are in the 2.25 - 2.75 inch TL range. I have an interesting way I size them. The big squares below are 1 inch and the smaller ones are 1/8 of an inch.
View attachment 1517516View attachment 1517517
The 3 fish I posted are from the 6 fish above. I also believe that 2 or 3 are females.
I do not ship my plecos until they are over 1.5 inch TL. The problem with the B&W ones that are not zebras is that they all look very similar when young. When it comes to 236 and 173, almost all the young tend to look like sw 236. With 173, this fish really morphs. When they are born, and for some time thereafter, you would swear there are 2-5 different species in a single spawn unless you knew better because you know they are all from the same spawn. When younger and smaller they are almost impossible to ID them as 173.
As a result, I tell people that when buying 236, sw 236 or 173, it is best to pay up for larger fish. At 1.5 inches they almost all look like super white 236. But as they get bigger the tend to look like what it is they are. If you want to buy them when smaller, then it is best to buy from a known source. In fact even when larger the source matters for most of these fish.
I took possession of my sw breeder stock, and they were sold to me as RB line, they were close to 2 in. TL for 9 and then just over 1.5 in. for 4. They arrived in late 2019 and went into their own tank to grow. I have two groups of regular 236 and one is for sure the RB kine and the other is almost certainly. Both groups spawned at about 3 in. (+/- .25) TL an about 2.25 - 2.5 years old. However, my sw took longer to get going. So I was surprised you got a spawn so young/s,all. But this appears to a freak thing and they took longer to get into spawning mode it sound like.
Mine have been actively spawning for some time. I have only sold two groups (5 and 6 fish) for 11 fish so far. They were all 2.5 to 3 inches and averaged 2.75 for the group. I have yhe 6 fish group 2.25 - 2.75 ready to go. I have not decided where to list them. I normally sell my biggest fish first and then work down in size even as they are growing. In addition to the 6, I have 18 at 1.75 - 2.25 in. and 26 at 1.0+ to 1.5+ in grow-out, There are more in the breeding tank, mostly recently free swimming to a few left behind when I pulled the ones to grow tanks.
My experience with all of the B&W Hypans I have kept (zebra, 236, sw 236, 173, 173b, 450 and contradens) is that all of them tended to go into spawning mode once they started. This usually lasts for about 10 - 11 months and then they will break for a few (2.25 - 3.5) months and then will resume regular spawning. But this applies to groups. I have never worked with fewer than 6 fish of any pleco species. I would best describe the plecos I have kept as being like randy teenagers. But as they get older they slow down a bit. They do not stop for many years. But they are never as prolific as in the first 5 or 6 years of spawning.
My only experience with healthy fish refusing to eat is in hearing about it from others. Over the years all of the fish I have kept have been and are pigs. They will try to eat almost anything they think might be food. Moreover, most of them will eat food meant for other species if they get the chance. That said, I consider diet to be one of the few things we can control in terms of what we can do to foster breeding.
Fish naturally want to spawn. So, for the most part, we are trying not to do things which might discourage that. Parameters in the proper range. a proper hardscape, adequate space etc. But when it comes to die,t what we choose to feed and when is an active choice. Poor and/or inadequate nutrition can be the reason one's plecos do not spawn.
After almost 2 decades of feeding kensfish.com sinking sticks to my bottom feeders, I switched to Ebo-Aquaristik foods from Germany. I made my own blend from the potential choice of ken's sticks. I do the same with their flakes. I sold a few pounds of my kens sticks at my last club meeting. I only fed them about 15-20% of the time. My main foods are frozen and Repashy. But I am willing to feed the Ebo more than I did the kens.
Most fish will not starve themselves to death. They may reject new foods, but as long as they taste OK to the fish and have nutritional value, most fish will eat them sooner or later. Fish can go a long time without eating and be OK. It helps when a fish can watch other fish eating the food it is refusing.
Anyhow, you should be having a lot of fun here. I started with zebras and was able to leverage my way up to where I am now. But I started keeping fish later in life and I am now just too old to keep up with it all. I am just over the halfway point of a pre-planned exit from the hobby. I recently turned 75 and discovered I am an old man
