The shorter spines were a deep red and the thicker ones were paler, some with deep red ridges. It is possible that a few long ones were broken at this stage.
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Slate-pencil Urchin

Goniocidaris tubaria

Description:

This sea urchin would have been about 50 mm across. It had probably just died and been washed ashore - still had most of its short thick primary spines and smaller needle like secondary spines.
Pic 1 is of the top side (aboral) and Pic 2 is of the underside (oral) with the mouth in the middle. Just visible in pic 4 is a triangular white tooth-like structure in the centre which is part of a complex dental apparatus called the "Aristotle's Lantern".
The shorter spines were a deep red and the thicker ones were paler, some with deep red ridges. It is possible that a few long ones were broken at this stage.

Habitat:

Spotted on the rocky ocean shore - low tide mark on the south coast.

Notes:

The Aristotle's lantern is made up of muscles and 5 eversible calcareous teeth and plates that help with scraping off algae from rocks and sea floor. It is so called because the apparatus is shaped like a lantern. The individual parts are beautiful and intricate.
Thanks to Harry J Breidahl for the ID. Species needs confirmation.
Phylum Echinodermata (echinoderms), Class Echinoidea (Sea Urchins), Possibly Order Cidaroida, Family Cidaridae

No species ID suggestions

3 Comments

Leuba Ridgway
Leuba Ridgway 10 months ago

Thank you for the nomination, Daniele. One of the marine researchers commented that this species and G.impressa are equally uncommon but the distribution map on ALA does not appear to reflect this observation (to me anyway !)

Maria dB
Maria dB 10 months ago

Interesting description!

DanielePralong
DanielePralong 10 months ago

Your spotting has been nominated for the Spotting of the Week. The winner will be chosen by the Project Noah Rangers based on a combination of factors including: uniqueness of the shot, status of the organism (for example, rare or endangered), quality of the information provided in the habitat and description sections. There is a subjective element, of course; the spotting with the highest number of Ranger votes is chosen. Congratulations on being nominated Leuba!

Victoria, Australia

Lat: -38.48, Long: 145.16

Spotted on May 6, 2018
Submitted on May 7, 2018

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