Suzanne Williams

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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.

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

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In Our Time · Seashells · 30 Jul 2026 podcast

But for shelled mollusks, the general opinion is they don't see colours.

And for most species we've tested, they've got poor vision.

But there are a few exceptions.

Well, it's really interesting.

There's lots of different ways.

So for humans and mammals and birds, you can dissect an eye and find that there are two different types of cells.

There's cone cells and rod cells.

The rod cells help you see in dim light.

Cone cells are what you use to see colour.

And different types of cone cells have different photopigments.

And you need more than one photopigment to be able to detect different colours.

Humans have three different photopigments.

Some animals have more and can see more colours than we can.

Some animals see less, so dogs and cats only have two photopigments and their world isn't as colourful as ours.

There have been tests on things like octopus and they've been shown to only have one photopigment, so we know that they can't see in colour.

But invertebrates don't have rods and cones, so we can't look for those.

But you can tell in different ways.

You can still look at the anatomy of the eye and work out their spatial acuity.

But to work out whether they see color or not, you have to do different tests.

So if you do it genetically, you can identify the proteins involved.

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