#cidaridae

A Cidarid urchin found at the Everett's Quarry site in Kakanui in North Otago. The deposit formed around the summit of an extinct underwater volcano in the early Oligocene, and is remarkably rich in fossil diversity. A single 235 gram (8.3 ounce) sample from an upper layer yielded about 300 different species of brachiopods, molluscs, bryozoans, foraminifera, ostracods, corals, echinoderms, serpulids, and barnacles.

If this species was anything like the living members of its genus, it was nocturnal and fed on sponges and other invertebrates.

Most Cidaroid sea urchins live in the deep ocean, but Phyllacanthus species are common in shallow tropical waters. Cidaroids have thick, heavy tests, and robust spines that may be club, fan, or even christmas-tree-shaped.

Impacts of debris and fishing litter on the rocky bottom of the Tyrrhenian Sea, Italy

A) Ghost net covered in various epibionts such as sertulariid hydroids, Paramuricea macrospina, Alcyonium palmatum and Cidaridae sea urchins (Banco Scuso – prof 140 m). 

B) An old lost net entangled on a colony of violescent sea-whip (Paramuricea clavata) and stretching over a mixed assemblage of yellow gorgonian (Eunicella cavolinii) and red coral (Corallium rubrum)(Ischia – prof 118 m). 

C) Lost net, hosting the basket star (Astrospartus mediterraneus), entirely wrapping a rocky boulder and stretched over a population of Paramuricea macrospina (Banco Scuso – prof 120 m). 

D) Gorgonian colonies of Viminella flagellum and Callogorgia verticillata, hosting the crinoids Leptometra phalangium, entangled and pulled by lines (Banco Marco – prof 270 m). 

E) Old long line entangling a colony of (Savalia savaglia), peeling off the tissue of the gold coral. Polichaeta Filograna implexa, and sponge Poecillastra compressa and gastropods occurring on its dead parts (Porto corallo – prof 90 m). 

F) Fishing lines entangled on the black coral (Antipathella subpinnata) (Banco Scuso – prof 140 m). 

G) Encrusted glass bottle (Amalfi – prof 94 m). 

H) Discarded tire and net (Amalfi – prof 84 m). 

I) A hanging rope hosting some specimens of sea urchins Cidaridae (Banco Marco – prof 270 m). 

J) A sack laid on the seafloor attracting Swallowtail Sea Perch (Anthias anthias) and other benthic species (Nisida – prof 77 m). 

K) Epibionted net and other litter snagged on a rock (Isola del Toro -prof 97 m). 

Scale bar: 10 cm

Goniocidaris mikado

Goniocidaris mikado The tip of spine over the upside shell is shaped like a dish. Only upper side spines have dish-shaped tip. Is this for defending?

ミカドウニ 殻の上部についているトゲの先端が、皿状になっています。 皿状になっているのは、上部のトゲだけです。身を守るため？

Prionocidaris baculosa

Prionocidaris baculosa

ノコギリウニ

Phyllacanthus imperialis

This sea urchin is named "Bakudan-Uni" in Japanese, which means "Bomb sea urchin".

バクダンウニ

Prionocidaris baculosa