Sea urchins and sea stars are special creatures at our house, and complete dead specimens are exciting finds while beach combing. Having been into marine organisms for sometime, I have a few that I have collected from local beaches and some from far away oceans.

tall urchin stack

I pulled them out recently now that Luna and Blake are both able to take more care with such fragile items.

sea star and urchin stack

Sea urchins are wonderfully tactile, all the little dimples and bumps, the perfect lines that curve from the top opening to the bottom opening, and we talk about how they can be broken into sections, how the creature moves and eats, and what eats it!

We have found Aristotle’s lanterns, the name given to the unique mouth piece of an urchin, and looked at how they work. Here’s one we have looked at, from a Kina at the beach in the summer, it is in five sections, just like the external structure:

aristotle's lantern pieces

The five sections have a kind of tooth that when assembled moves up and down, we couldn’t get it back together after it has dried completely.

echinoderms on the tray

Luna looking at the echinoderms, pacing the specimens on print outs of various anatomical illustrations.

echinoderms on the print outs

We talked a bit about the illustrations, but she was more interested in them as objects.

Blake looking at sea stars

She is very much into story telling, and creating ‘set ups’ as she calls them. As far as resources goes, we have been reading about the New Zealand Sea Shore, exploring rock pools (especially over summer) and looking into the salt water aquariums at the Auckland Museum. I was interested to see if Luna would draw on or colour the anatomical printouts, but she was content to study them and arrange sea stars on them.

You can learn a bit more about echinoderms here. The specimens I have, I have collected myself dead on the beach or are from older similar collections, I like to be sure that the specimens have been collected sustainably, without damage to their environment.

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