What laid these eggs?

[eschaton]

So, the other day I noticed the following eggs on the side wall of the glass of my reef tank:

As you can see, there are six - and only six - eggs. Each of the eggs is relatively large - a bit bigger than a sesame seed - with what appears to be a single embryo inside.

I would presume it was some sort of snail, given the location on the tank wall. They don't look right for trochus, cerith, or nerite eggs (all of which I have). My next best guess is they're the eggs from the mini-strombus that I got from Indo-Pacific Sea Farms. I know they're supposed to breed in tanks. Strombus do seem to lay egg sacs similar to these, though they typically have multiple eggs in each one - not a single egg like this.

Anyway, I'm stumped - particularly because little else besides the snails regularly climbs the glass.

 

[New&no clue]

I have the same snails as you and I've never seen eggs like that. What about a starfish or urchin, do you have either of those in your tank? Also can you confirm there are seven eggs, if not I need to get new glasses.

 

[sixty_reefer]

They are dove snail eggs, it’s a clear dome shape with a few white dots on the inside.

 

[eschaton]

What about a starfish or urchin, do you have either of those in your tank? Also can you confirm there are seven eggs, if not I need to get new glasses.

I do have some hitchhiker urchins, but they're all relatively small and I believe immature. One red tuxedo, which can't breed by itself.

Yes, sorry, seven eggs, not six. I guess I need new glasses.

They are dove snail eggs, it’s a clear dome shape with a few white dots on the inside.

As far as I'm aware, there are no dove snails in the tank. I did have some hitchhiker whelks, but they have all been moved to the sump. The other day I found what looked like a small cone snail, but it was less than 1 cm long and certainly not big enough to lay these eggs.

 

[sixty_reefer]

I do have some hitchhiker urchins, but they're all relatively small and I believe immature. One red tuxedo, which can't breed by itself.

Yes, sorry, seven eggs, not six. I guess I need new glasses.



As far as I'm aware, there are no dove snails in the tank. I did have some hitchhiker whelks, but they have all been moved to the sump. The other day I found what looked like a small cone snail, but it was less than 1 cm long and certainly not big enough to lay these eggs.

Are you sure it was a whelk and not dove snail? They are very similar.

 

[eschaton]

Are you sure it was a whelk and not dove snail? They are very similar.

Does this look like a dove snail to you? Because that's what I have.

The snail I just exiled to the sump looked more like a dove snail, since it had a whitish, shiny shell. However, it was crawling on the opperculum of a closed-up nerite, which seemed like predatory behavior to me.

There's some very small whelk/strombus looking guys in the tank (2-3 mm in length) that I tend to not bother because I figure even if they're predatory they're too small to predate on any inverts of any size. They don't seem to be getting bigger, and certainly didn't lay these eggs, which are basically the same size they are.

Also, you said dove snails lay multiple eggs in each sac. There's only one egg in each of those seven things.

 

[35ppt]

Redacted

 

[eschaton]

What do they look like from the side? Like this?

They are not on stalks like that. On the other side they're just rounded off like little suction cups on the glass.

 

[35ppt]

Redacted

 

[KJ]

Look like Columbellid eggs.