Collection of sea urchin shells, a beautiful display of five-fold symmetry in nature.
(by seagems_australia)
Thread
(by seagems_australia)
Thread
There are about 950 known species of sea urchins, so this is just a sample.
Sea urchins are echinoderms (a group of animals which also includes sea stars, sea cucumbers, brittle stars and crinoids). Adult echinoderms are characterized by their radial symmetry, usually 5-point ⭐
Sea urchins are echinoderms (a group of animals which also includes sea stars, sea cucumbers, brittle stars and crinoids). Adult echinoderms are characterized by their radial symmetry, usually 5-point ⭐
Some examples of different species of sea urchins:
Coelopleurus granulatus, Stylocidaris amboinae, Mespilia globulus and Coelopleurus floridanus
Coelopleurus granulatus, Stylocidaris amboinae, Mespilia globulus and Coelopleurus floridanus
A rare species of sea urchin from the deep waters in Western Australia, Phyllacanthus irregularis. It's been backlit to show the porous areas of the shell (know as test).
Most sea urchins have pentameral symmetry, but not all.
Here's a tetramerous species, with 4 parts, 'Heliocidaris erythrogramma' (it's been backlit to show the pattern).
Here's a tetramerous species, with 4 parts, 'Heliocidaris erythrogramma' (it's been backlit to show the pattern).
All photos by @seagems_australia. Check out their Instagram, they have a very cool collection of sea urchin tests, with some rare species. Also some amazing shells 🐚💚
instagram.com/p/CMeEvt0Bs8F/…
instagram.com/p/CMeEvt0Bs8F/…
A sea urchin from Patagonia, Arbacia dufresnii, before and after losing the spines.
Pentameral perfection
Pentameral perfection
Two more sea urchins:
Hesperocidaris perplexa (Sea of Cortez, Mexico)
Acanthocidaris maculicollis (Balut Island, Philippines)
There is beauty in geometry 💚
Hesperocidaris perplexa (Sea of Cortez, Mexico)
Acanthocidaris maculicollis (Balut Island, Philippines)
There is beauty in geometry 💚
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