Phylum Mollusca

Class Gastropoda

 

HAWAII

Family Patellidae

Limpets

Limpets have umbrella-like shells and graze upon algae on rocky shores.  Four endemic species in Hawaii.  Highly prized for food and quite rare due to harvesting.

 

Cellana sandwicensis   

Kaunolu Bay, Lana'i

 

Kaupo, Oahu

Kaupo, Oahu

 

Portlock, Oahu

Ahihi-Kinau NAR, Maui

HAWAIIAN LIMPET    OPIHI

On boulders in the lower intertidal zone.  Has coarse ribs of equal width and animal's foot is yellow.  Shell interior is light gray; attains 2.5 inches.  Endemic to Hawaii.

 

Cellana exarata   

Has fine ribs of two sizes, gray foot, dark gray interior.  Lives in the high intertidal spray zone.  About 2 inches.  Endemic to Hawaii.

Cellana talcosa   

Ahihi-Kinau NAR, Maui

Found on boulders in shallow water exposed to large waves.  Attains 4 inches.  Shell interior is white.  Endemic to Hawaii.  Nearly absent north of Moloka'i.


Family Fissurellidae

Keyhole Limpets

Keyhole limpets have umbrella-like shells with an aperture or slit in the shell to expel waste.

 


Family Hipponicidae

Cap Shells

Small limpet-shaped snails that secrete a shelly plate on hard substrate.  Common but often overlook due to their small size.

Hipponix imbricatus

Kaupo tidepool, Oahu

SCALY CAP SHELL

Common in groups on rocks in shallow water.  About 1/2 inch.

Hipponix australis

Kapoho tidepool, Hawaii

 

CONICAL HOOF SHELL

Found attached to snails, usually several on one host.  Spire curves backward.  Attains 1/2 inch.  May feed upon feces of host snail or hermit crab.  Leaves deep scar on host shell.  Hawaii & the Indo-Pacific.  Formerly known as Sabia conica.


Subclass Pulmonata

Air-Breathers

 

 Family Siphonariidae

Siphonarid Shells

Small limpet-like shells with a subtle gap or sinus on the right side.  They are air breathers lacking gills.

 

Siphonaria normalis

Mokuleia, Oahu

 

Kaupo, Oahu

Black Point, Oahu

 

Diamond Head, Oahu

Portlock, Oahu

Abundant on rocky shores above the waterline.  Ribs vary in size & arrangement.  Less than 3/4 inch.  Hawaii & the Indo-Pacific.



NORTHEAST PACIFIC

Family Patellidae

Limpets

Notoacmea persona

Ogden Point, Victoria, Canada, 3 feet

 

Ogden Point, Victoria, Canada, 3 feet

Ogden Point, Victoria, Canada, 3 feet

Ogden Point, Victoria, Canada, 3 feet

SPECKLED LIMPET

Abundant on rocks in the intertidal zone.  Up to 2 inches.


Family Fissurellidae

Keyhole Limpets

Megathura crenulata

GIANT KEYHOLE LIMPET

Locally common on rocky reefs.  Mantle color variable.  Attains 5 inches.  Northern California to Baja California.

 

 


Family Haliotidae

Abalone

Haliotis kamshatkana

Ogden Point, Victoria, Canada, 6 feet

NORTHERN ABALONE

Found on rocks in shallow water.  Up to 7 inches.  Alaska to Central California.

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