CreatureCast is a collaborative blog produced by members of the Dunn Lab at Brown University, along with assorted friends. This project, which is focussed on zoology in the broad sense, serves as a forum to present original content that we have produced and observations by others that we find interesting and beautiful. Support for some original podcast content is provided by the National Science Foundation (NSF). Mollusc themed podcasts are supported by a collaborative NSF research grant to Casey Dunn, Gonzalo Giribet, and Nerida Wilson.

The blanc conundrum

The siphonophore Hippopodius hippopus is usually transparent, but when disturbed it suddenly becomes milky white.

Two urchins

The green urchin and the pencil urchin are alike in many ways, but their differences matter in a big way when it comes to their ecological impacts.


A look into the microscopic army in every cnidarian that's just waiting to sting you.


Many organisms move with cilia. Most, like Stentor, are small

Nudibranchs and defense

This episode explores how nudibranchs steal jellyfish stinging capsules to defend themselves while also getting a good meal


This is the story of a parasitic barnacle with a fascinating lifecycle

Tyrian purple

Nina Ruelle tells the story of Tyrian Purple, a dye created from the marine snail known as Bolinus brandaris

Echinoderm skin

This episode of CreatureCast tells the story of how echinoderms (starfish, sea urchins, and their relatives) can change the stiffness of their skin at will.

The pistol shrimp

Kevin Rogers, a student at Brown University, explains how a little pistol shrimp manages to pack a big punch through creating cavitation bubbles.

The Nautilus

How does the nautilus swim underwater, even though it has no fins and lives in a shell?

CreatureCast: Getting Around When You Are Round

Humans have a front and a back and two legs. We walk around on our two legs. When we need to change the direction we are moving in, we first turn our body to face the new direction and then use our same two legs to keep going. It works for us. But, what about a round animal that also has an odd number of limbs?

Creaturecast: Hollow Trees

Here is a little plant that starts it's life high up in the tree tops, where it can find more light than the dark understory of the rainforest. As it grows though, soon getting enough water becomes limiting factor, and the plant will drop a shoot to the ground.