during the years - most pronounced rather recently - I gathered some experience in artifical hatching pleco eggs, both good and bad ones. The reasons are multiple, deliberate and accidental, ranging from males constantly kicking out eggs, males constantly eating eggs, to the occasional desire to better control numbers.
I have essentially settled on two different methods, a low maintenance and the traditional high maintenance method with very frequent water changes and changing the hatching container daily. Choice of method depends on the species, I experienced difficulties with certain species using the "traditional" approach (for example, I never managed to hatch a single egg of L59 with the traditional approach, while I achieve success rates of near 100% with the lazy way).
While I currently ponder the thought of writing an article on this topic (which would probably take some time), I figured I could share my most recent experience with artifical hatching of a Pseudacanthicus spawn.
This spawn was taken deliberately from the male the day after spawning, because I am currently working on answering a different question (but that is a topic for yet another article).
So this would be the spawn of Pseudacanthicus sp. (L 65), less than 8 hours after spawning, which happened during the night of August 22nd to August 23rd:
Never bothered to count them.
Since I am not overly successful in hatching Pseudacanthicus using the high maintenance way, I used the low maintenance way (which I have done several times before with Pseudacanthicus).
For this, the spawn is placed in fresh water (from the tap; if you like, you can also mix it with RO water, but that never made a difference for me), don´t use tank water! I never bothered to adapt the eggs to new water: I even dumped spawns from soft and acidic (conductivity below 100µS/cm, pH below 6) into my tap water (conductivity: 400µS/cm, pH around 7.5) and hatched them with near 100% success. Add a drop of your favorite anti-fungal agent to it, an air stone (if the spawn is large, it is best placed in a net) and then hang the whole thing into one of your tanks with the temperature you want for hatching (about 29°C in this case). Looks something like this (this is not this actual example, but it´s no different):
All you do then is remove dead (white) eggs once a day. You should be thorough with this, meaning to try and remove the complete egg, try not to spill too much yolk in the water. Unless you have an accident with a lot of yolk in the water, don´t change water or the hatching container.
In this case I only had to remove dead eggs after the first and second day (two and one, respectively).
A three day old spawn looks like this:
A total of five larvae hatched prematurely and none of them made it through their first night.
The actual hatch happened on Friday August 29th, so basically 6 days after spawning. This is the time where you want to change the water (100% of it), because otherwise the protein from the egg shells will quickly spoil the water (the airstone will produce a nice, foamy surface; a process we all know from salt water hobbyists who use foaming to remove protein from the water, but not used in fresh water).
I counted them using this picture and came up with a total of 328 larvae. I probably missed a few and I will have to remove some of them during the raising process: I could already identify a few with deformities such as tilted or twisted spines.
Adding the total of eight I had to remove during the hatching process, this spawn consisted of at least 336 eggs, from a female measuring less than 15cm TL (less than about 6 inch total length).
The "success rate" so far would be 97.6%, high enough for my aspirations.
Now I need to identify a tank to raise 300 Pseudacanthicus in..
Cheers,
Sandor
P.S.: One word of caution: this does sound pretty simple and streight forward, but bare in mind that this is basically the culmination of about 10 year´s worth of experience of artifical hatching of pleco spawns (not too successful in the beginning) and I only started trying to do this with Pseudacanthicus spawns about a year ago. So just like everything around keeping and breeding fish, this is not a fail-safe recipe and don´t expect it to work the first time around. I wouldn´t be surprised at all if others have difficulty hatching them this way but succeed using the high maintenance way (which does not work for me).