Elacatinus oceanops

I can’t find convincing info about whether these fish are sequential hermaphrodites or have determined sexes; in any case it was pretty easy to get a pair, I never had more than three or four fish together at a time but always managed to wind up with a pair. They spawned frequently in a capped 3/4″ pvc tube. I made various attempts at hatching, sometimes by leaving the parent in the tube and sometimes by removing the parent and forcing a hatch with aeration. I believe the classic mechanism is to tickle the eggs with a feather.

Getting fry was easy! The fry almost always died in a day or two, too soon to be from starvation. Most losses were due to getting stuck on the surface of their tank or tub; it wasn’t until I found the right aeration level (with big bubbles) that I was able to get some fry past the first few days.

After that, a few fry grew quickly on a diet of rotifers in a black tub, but losses were high for the first couple of weeks. I used the same low-density rotifer + phyto technique (in the same tub) that I used to raise clownfish.

Unlike clownfish, it took nearly a month for the fry to settle. Here are fry a few weeks in, still fully pelagic:

And here they are after about 30 days, acting like gobies:

They went from transparent and most invisible to little blue lightning bolts almost overnight. Once they settled care was simple; many of the fry grew up in the care of a fish-sitter while I traveled, only eating tdo and without live foods.

I gave the pair that produced the above fry to Bill Capman where he raised quite a few more fry in his elaborate setup at Augsburg University. The fish I gave him turned out to be harboring Cryptocaryon so the gift was a bit of a disaster (and, in retrospect, this may account for the poor survival rate of my fry as well.)