spiral plaque of eggs?

[Greengirl]

What is this? Found a couple of these 3-5 mm diameter plaques on the glass walls near the air surface. No fish in this aquarium, but lots of pods, tube worms, snails, anemone, and a pair of Elysia tucca sea slugs. I was hoping the slugs would breed but this doesn't look like their kind of egg mass.

 

[redfishbluefish]

What snails do you have? I know Cerith snails make spiral egg masses.

 

[Greengirl]

I've got lots of healthy dwarf ceriths, some Florida ceriths, nerites, and a couple of bumble bee snails.

 

[EeyoreIsMySpiritAnimal]

@ISpeakForTheSeas

 

[EeyoreIsMySpiritAnimal]

What is this? Found a couple of these 3-5 mm diameter plaques on the glass walls near the air surface. No fish in this aquarium, but lots of pods, tube worms, snails, anemone, and a pair of Elysia tucca sea slugs. I was hoping the slugs would breed but this doesn't look like their kind of egg mass.

Never seen anything like that. Hopefully others with more knowledge can help ID.

 

[Greengirl]

Right...googling along suggestion of cerith snails and that looks right. Maybe my dwarfs or my Florida ceriths, but not anything new to the tank : ). Thanks Paul!

 

[ISpeakForTheSeas]

What is this? Found a couple of these 3-5 mm diameter plaques on the glass walls near the air surface. No fish in this aquarium, but lots of pods, tube worms, snails, anemone, and a pair of Elysia tucca sea slugs. I was hoping the slugs would breed but this doesn't look like their kind of egg mass.

I'm actually thinking this is the Elysia eggs - for example of Elysia sp. eggs see image G below (there are other species with similar egg spirals too):

Source: https://www.researchgate.net/figure...ss-A-B-Live-specimens-resting_fig58_306006471

 

[Greengirl]

OMG!!! That would make me soooooo happy. Hope you are right! And in fact the pic looks a lot more like these than the snail eggs. I just hope the copepods or whatever don't eat the eggs before they can hatch. Also weird to me that the slugs prefer to lay the eggs up high on clear glass than down in the plants, but who am I to judge. I did notice one slug up in that vacinity recently so could be that's why. How long before they hatch?

 

[ISpeakForTheSeas]

OMG!!! That would make me soooooo happy. Hope you are right! And in fact the pic looks a lot more like these than the snail eggs. I just hope the copepods or whatever don't eat the eggs before they can hatch. Also weird to me that the slugs prefer to lay the eggs up high on clear glass than down in the plants, but who am I to judge. I did notice one slug up in that vacinity recently so could be that's why. How long before they hatch?

For most species, it seems they tend to prefer to lay on algae, but sometimes they'll lay on the glass anyway. I'm not exactly sure how long before the eggs hatch for your species, but given that Elysia timida takes up to 3 weeks, E. clarki ~16-18 days, and E. cornigera ~15-19 days, I'd guess your eggs would be in that same range. So, probably 2 to 3 weeks.

Sometimes with E. timida and E. cornigera (and likely with some other species too), the eggs will hatch into fully formed, crawling juveniles, but most of the time they hatch into free-swimming veliger larvae (the veligers don't typically survive in our tanks, but the crawling juveniles likely would).

 

[Greengirl]

For most species, it seems they tend to prefer to lay on algae, but sometimes they'll lay on the glass anyway. I'm not exactly sure how long before the eggs hatch for your species, but given that Elysia timida takes up to 3 weeks, E. clarki ~16-18 days, and E. cornigera ~15-19 days, I'd guess your eggs would be in that same range. So, probably 2 to 3 weeks.

Sometimes with E. timida and E. cornigera (and likely with some other species too), the eggs will hatch into fully formed, crawling juveniles, but most of the time they hatch into free-swimming veliger larvae (the veligers don't typically survive in our tanks, but the crawling juveniles likely would).

I just found this reference that specifically documented E. tuca and I'm hopeful with some fresh H. incrassata the hatchlings will morph and survive. Fingers crossed.

 

[ISpeakForTheSeas]

I just found this reference that specifically documented E. tuca and I'm hopeful with some fresh H. incrassata the hatchlings will morph and survive. Fingers crossed.

Great find with that document - good luck!