Florent's Guide To The

Eastern Pacific Reefs

East Pacific Slate Pencil Urchin
Eucidaris thouarsii
East Pacific Slate Pencil Urchin
Category: Pencil Urchins
Scientific Name: Eucidaris thouarsii
Size: Up to 6 in. (15 cm)  
Depth: 3-200 ft. (1-60 m)
Distribution: Gulf of California, Pacific Coast of Mexico to Panama
Echinodermata (Phylum)
└Echinozoa (Subphylum)
 └Echinoidea (Class)
  └Cidaroidea (Subclass)
   └Cidaroida (Order)
    └Cidaridae (Family)
     └Eucidaris (Genus)
      └E. thouarsii (Species)
WoRMS ID: 513266🔗
iNaturalist ID: 57294🔗

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© 2026 Florent Charpin