I know that certain sources will list their egg size but not everyone will, and off the top of my head I cannot think of them. If you have any questions of a certain species, I'm pretty sure there is someone on this forum that will be able to answer it for you. All of the commonly kept species you will be able to find the egg size here.
Norman gives egg size in "Cephalopods: a world guide.
I have had females of the following species that laid eggs.
A. aculeatus small
O. cyanea small
O. mercatoris large
O. joubini smalll
O. rubescens small
O. micropyrus large
O. chierchiae large
O. bocki small
O. wolfi small
O. diguti small
H. lunulata small
H. fasciata large
H. maculosa large
H. (GBR undescribed) large
Professor, your answers always make me have more questions .
Of the group you list, I recall you have been successful with raising O.mercatoris, O.chierchiae, H. lunulata (didn't know these were a small egg species ) and I thought O.bimaculoides to adults (please correct me if I misremember). Were you successful with any of the others?
I have had no luck rearing any small egged species including H. lunulata. The big egged species that we have gotten through are O. bimaculoides, O. chierchiae, H. (GBR), O. mercatoris and an undescribed O. mercaoris like thing from Belize.
I have been working in the labs of colleagues who reared H. fasciata and H. maculosa.
The one female O. micropyrus that we had had laid sterile eggs - probably had not mated. I would love to try again!
Was the O. mercatoris like thing, usually a gold color with a black ocellis and diurnal? I am so trying to figure out what this little guy I have is that any straw is grasped and Belize is a viable migration point
I thought I remembered a post about a lab hatching out a high percentage of the blue rings a couple of years ago and another with some juveniles that had issues with vibrio if they were kept in close contact. I think that is why I thought they were a large egg species. Were those H. maculosa (I am pretty sure they were not the blue lined guys since they are different enough to be easy to tell the difference in photos)?