What's in my fishbowl? (Part 1) Snail eggs!

Jul 30, 2023 • 8:17 PM UTC

Bengaluru Urban, Karnataka, India

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Animals

Mitali

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Hello all!
I recently brought home a couple of fishes and snails from a pond on NCBS campus. I usually keep an eye on these ponds because they're full of life and fun to watch. It usually has lots of lillies and hydrilla plants. I got some hydrilla plants and algae as well. I also have lots of Planaria whose population is going down these days for some reason.
Its been a few weeks since I got these guys home and recently found some strange looking things on the walls of my fishbowl which turned out to be snail eggs.
I've Foldscoped these at several stages. Here are the pictures and videos:
Eggs in the fishbowl

The earliest stage where the embryos are just a mass of cells

There is a large egg sack of jelly-like substance that holds the eggs. It prevents the eggs from desiccating. The embryos are the little yellowish-white dots inside the eggs.
After 2-3 days

Doesn't quite look like a snail yet but something like a primitive foot that is helping the embryo swim.
After 3-4 days

At this stage they have developed the shell and the muscular foot.
After 4-5 days

At this stage, they have fully developed the shell and the rest of the body. The eyes are also clearly visible as two black spots. The gills are visible at the dorsal region. Initially I thought that's the heart but a few google searches revealed that that's the gills. About two days after this stage, the snails hatched out of the eggs.

I have a new lamp that I use to illuminate my samples which I've been playing around with and which is also why all the videos look different. Sharing that in the next post!

Cheers,
Mitali