Manu Bustelo

Macro video of a sea urchin, viewed almost straight down into the dense forest of its spines.

This video is particularly interesting because you can see much more than just the spines:

* Long primary spines: The orange, golden, greenish and brown rods radiating outward are the urchin’s defensive spines. Their apparent colours are strongly enhanced by the underwater lighting and reflections.

* Tube feet: Among the spines you can see numerous thin, flexible, almost translucent structures. These are tube feet, part of the urchin’s water-vascular system. They help it move, attach to surfaces and manipulate food.

* Tiny suction tips: Some of the pale blue/white rounded ends are the terminal parts of tube feet, which can act almost like microscopic suction cups.

* Pedicellariae: The small, delicate structures between the spines include pedicellariae—tiny pincer-like organs used for cleaning the animal’s surface and, in some species, defence.

* Radial architecture: Everything radiates from the centre because the urchin’s body is organised around fivefold radial symmetry, a defining characteristic of echinoderms.

* Depth-of-field: The centre is relatively sharp while the spines toward the edges become progressively blurred. Combined with the radial arrangement, this creates almost a cosmic / alien landscape effect.
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🎥#shotoniphone using @divevolk underwater case.
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#scuba #unoceandecade #natgeoyourshot #orcatorch