OK, since it was late and I was looking for a quick response I did not get to put a lot of information into my post. So here it goes.....
I have a Black Banded Cat shark egg. I can't tell you how old the egg is because my local store does not get that information when they order them. I have had it in my tank now for about 1 month. I have watched it grow from about 3 inches to what looks like 5-6 now. There appears to be no sac left. two weeks ago it was the size of a green pea.
The tank is a 150 gal about 6' x 1.5' x 2'. I have had the tank for 4 years, and set it up myself. I cycled the tank with live sand, live rock, and mixed my own water. I do once a month water changes, about 10%. I have two large canister filters, and a small fluval, along with a UV sterilizer, and a Protein Skimmer. I have about 80 lbs of live rock and a 2" base of live sand. Lighting is provided by 2 36" poer compacts w/moon light. I have them set for about 6 hrs per day to cut back on algae. The tank gets no direct sunlight.
I have 5 clowns, 1 blue damsel, 1 cleaner wrasse, humu trigger, white tail tang, Naso Tang
, and a pearlscale butterfly. I have 2 purple anemones, a sand sifting star, about 5 hermits, and a emerald crab.
I have been running salt tanks for over 10 years, with no problems. I have helped friends set up their aquariums and they've had no problems. My local store is often impressed at my water quality and the fact that my tank mates get along without fighting. I have had a shark egg before, but the last one I had did not eat when it hatched. I tried frozen squid, ghost shrimp, silver sides, brine, and dried shrimp. I tried both hand feeding and letting it feed for itself.
Ok, I think I covered everything. If there is something I missed let me know. So once again, at what point can I tell that this one won't make it out on his own? I did notice, that since last night he has maved inside of the egg. It does not look like he tried to push his way thru, but he has moved his body.