Suzanne Williams

speaker

225 appearances 1 recordings 1 series first heard Jul 2026 last heard 30 Jul

Suzanne Williams’s voice in public audio — every appearance, attributed to the second.

Trend

recordings per month · last 12 months

Recordings per month over the last 12 months — 1 in all, peaking in Jul 2026 with 1.

newest first · ▶ plays the moment

In Our Time · Seashells · 30 Jul 2026 podcast

Yep.

The phylum mollusca, it's the second largest phylum of animals.

The largest are the arthropods with insects and crustaceans.

But molluscs have about 89,000 validly named extant species, so living, not fossil species.

And of these, the phylum is divided up into seven classes.

And of these, the absolute largest by far and away are the gastropods.

And this group are your typical slugs and snails that you see in your garden.

They account for about 76,000 validly named species.

So this really is by far the biggest group.

They live in the sea where they're most common, but they're also found in freshwater and on land.

And many of them have shells.

You have some that don't.

So you have garden slugs and you also have nudibranchs, which are beautiful, colourful marine slugs.

But these ones produce the sorts of shells that we typically think of as seashells.

So you get turban-shaped shells, top shells, spindles, limpets.

All of those are gastropods.

The next biggest group are the bivalves, and there's about 10,000 species in this group.

And this group are found in freshwater and the sea, but not on land.

And they have two shells, and they're joined together by a hinge.

So they're bivalves, two valves.

Showing 1–20 of 225 · page 1 of 12