romunov’s blog et al

Most of the kids have ran for the hills. I couldn’t spot any on the front glass, or anywhere else for that matter. One powerhead was directed right into the capsule, which could have dislodged them and swept them to another part of the tank. With many dreadful Aiptasia all around, I don’t know if they would survive such a stochastic journey. I have redirected the PH and will observe further.

They probably have a lot of predators, most noticable are probably Eunicid polychaetes. I of course have no physical evidence that they eat them, but I did saw them eat baby stomatellas about a year ago. First I thought it was cleaning its house, but after a few “licks” it swallowed it whole. The beasts are about 10 cm long with a diameter of a few mm.

I’ll see if I can catch a female in depositing a capsule. That time, I’ll try to document the progression every day. This hasn’t been possible in the last run.

Conclusion:
Columbellids in my tank take about 25 days to develop from freshly deposited egg in a capsule to juvenile. Veliger stage becomes very obvious around day fifteen. To confirm the results, I’ll have to document a few more capsules.

The snails are fully developed juveniles. They probably chewed their way through the capsule. Notice the small hole in the middle of the capsule. In every capsule I saw (over the years), the hole appeared on the same spot. Even when the capsule is deposited, there is an interesting flat circle on top of the dome, some sort of a cap maybe. It would be interesting to learn how they know where to puncture through. Chemical queue, physical (flat(ter) surface…?

The snails are growing fast. Any day now!

Pics on day twenty one. Notice the well developed shell. These buggers are almost ready to “hatch”.

A slight difference in development. Notice the velum (part of a band of cilia called the prototroch) still present in some larvae. These larvae remind me of butterflies, due to the velum shape. The brown “thing” above the capsule is a flat worm.

Here is a close-up of a bigger speciment of flat worm.

Here is one of the capsules on day fifteen. The embrios have moved around quite a bit. Also, they’ve grown - lucky for me, since my camera isn’t quite successful at recording those minute object.

They’re really kicking it off now!

Note to self: I changed the counting days appropriately. It would seem my brain stroke off for a day, so everything was set back one.

This are eggs on day seven. I had to keep the picture a bit larger, to show the change in shape of the embrios.

Still no progress, but be sure, the eggs will soon take a bit different shape!

Almost no visible progress on day three. The “smudge” you can notice around the egg capsules are mostly algae. A lot of small crustaceans and flatworms graze on them.

I’ve decided to keep you up to date with the little snail project I started. I noticed two snails met on the front glass a few days ago, and I knew we’re in business - that is, that I’ll be seeing some egg capsules soon. Well, soon has come, and two appeared on the front glass a few hours ago. I’m adding a picture (from last year) of the parent and two capsules at day one.