In short, after probably 15-20 birthing episodes, I have been totally unable to keep reidi fry alive longer than a few days. I just got 65 more this morning and put them in the nursery. My adult males are continously pregnant so I have an ample supply for research.
The 3 young seahorses I have successfully raised to adulthood are not reidi. I think they are either tigertails (H. comes) or Barbouri (H. barbouri). With all the natural variability it is just too hard for me to tell the species definitively, perhaps they are sterile hybrids since mom and dad look so different. These were born much larger than reidi, hitched the first day, and were much more active and inquisitive from day 1. They have grown up fast once weaned away from baby brine shrimp and onto frozen mysis. One only took 2 days to start eating mysis after placement in the main tank with adults, the other took 3 weeks, and the third took over 7 weeks and was near death before taking mysis. Now all are growing fast but the difference in timing with mysis is reflected in their size.
I have several theories about why reidi die. My nursury is a bare bottom Eclipse 12 with sponge filters, live rock, and lots of cheatomorpha macroalgae. I was losing half a hatch the first night, half again the second night, by day 4 there were only 2-3 left swimming. No dead bodies anywhere. I thought it was predatory amphipods that come out at night so left the lights on continuously. That really improved survival but all were still missing within 10 days.
I cleaned out everything, killed the live rock (amphipods and bristleworms), reduced the chaeto to keep them below the water surface (bubbles kill them?) and tried again. No avail. I am still only keeping them for about 10 days max with baby brine shrimp. They eat, take on black color, run around, etc... but are simply missing the next day. I could understand if they were dead on the bottom, and I doubt the snails eat them. There may be some predator I haven't eliminated (no further signs of hydroids either).
I was hoping to start selling them to offset the cost of mysis for the adults(about a dollar a day), but with only 3 produced so far, my time investment and fatherly love is overwhelming. They would be the very last thing I would sell on earth! They are so cute and inquisitive, they will even play with me at the front of the tank. I thought all 3 were female, but suddenly one had a growth spurt (length) and developed a pouch. After having a pouch for only 8 days, he started the courtship ritual with a big female. It was hilarious since he was so small compared to her. Needless to say he has a new nickname I can't say here.....
As I said above, I just got 65 more this morning, and will keep up the research. Any ideas are welcome.