pencil urchin Ctenocidaris perrieri

Ctenocidaris perrieri is found in Antarctica and the Antarctic Peninsula, Kerguelen Island, Crozet Island, and Heard Island from 6 to 602 meters depth [1,2,5,6,7]. The test (shell) of C. perrieri has been measured at sizes up to 6.7 centimeters and is purple or purple brown in color [7,8,9]. The primary spines of C. perrieri are typically twice as long as the horizontal diameter of the test (shell) [2].



Here's a closer look.

Ctenocidaris perrieri has long, slender, coarsely thorny primary spines measured at lengths up to 8.5 centimeters and covered with a thick, spongy coat of hairs [2].



Ctenocidaris perrieri broods its embryos and juveniles in the region surrounding its mouth (the peristome) [3,8].

The diversity of Antarctic sea urchins with its prevalence of brooding (thirty-nine of sixty Antarctic and subantarctic species -- 65%) may be a process of species-level selection via extinction and speciation rates related to pelagic or protected development of their young [3,4].

1: Bulletin du Museum National d'Histoire Naturelle, Section A, Zoologie, Biologie, et Ecologie Animales 14(2):405-441, 1992; 2: A Monograph of the Echinoidea. Volume 1, Cidaroidea. T Mortensen. Copenhagen : CA Reitzel, 1928. pp123-124; 3: Evolution 50(2):820-830, 1996; 4: Vie et Milieu 47(4):381-387, 1997; 5: NZOI Records (New Zealand Oceanographic Institute) 3(1):1-6, 1976; 6: Jim Mastro, personal communication, 1999 [6 meters at Explorer's Cove in New Harbor]; 7: Equinodermos Antarticos. I. Equinoideos. 1. Equinoideos de Shetland del Sur y Archipielago Melchior. I Bernasconi. Revista del Museo Argentino de Ciencias Naturales "Bernardino Rivadavia" e Instituto Nacional de Investigacion de las Ciencias Naturales. Zoologia 9(9):197-210 and plates, 1969; 8: T Mortensen. B.A.N.Z. Antarctic Research Expedition 1929-1931. Reports, Series B (Zoology and Botany) Volume 4, Part 10 Echinoidea. pp. 287-310 plus plates. Adelaide : BANZAR Expedition Committee, 1950; 9: Echinodermes (Asteries, Ophiures et Echinides). R Koehler. Deuxieme Expedition Antarctique Francaise (1908-1910) commandee par le Dr Jean Charcot. Sciences Naturelles. Documents Scientifiques. Paris : Masson et Cie, 1912

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