Invasion History

First Non-native North American Tidal Record:
First Non-native West Coast Tidal Record:
First Non-native East/Gulf Coast Tidal Record:

General Invasion History:

Patelloida striata has a broad native range in the Indo-Pacific from central Japan to the Caroline Islands, north of Papua New Guinea (Kurihara 2002; Academy of Natural Sciences of Philadelphia 2013). This limpet was reported to be abundant in Samish Bay, Washington (WA) in 1924, after the planting of Japanese Pacific Oysters (Crassostrea gigas) and was later seen on a shipment of oysters to Willapa Bay, WA (Kincaid 1949, cited by Hanna 1996 and Carlton 1979).

North American Invasion History:

Invasion History on the West Coast:

Patelloida striata (as Acmea heroldi signata) was reported to be abundant in Samish Bay, Washington (WA) in 1924, after the planting of Pacific Oysters (Crassostrea gigas) from Kumamoto, Japan and was later seen on a shipment of oysters to Willapa Bay, WA (Kincaid 1949, cited by Hanna 1996 and Carlton 1979). This species did not established in Washington.


Patelloida striata is a small limpet with a flattened cone-shaped oval shell, which has an apex at the anterior end. The shell is marked with concentric growth rings and strong ridges radiating from the apex. The shells occasionally reach 24-33 mm in size, but more often are a maximum of 12-18 mm. The color of the dorsal surface is dark to light brown, with streaks of white scattered along the rays. The interior of the empty shell is pearly, with a dark oval in the center, said to resemble the shape of an owl, typical of the family Lottidae (Owl Limpets). Description from: Abbott 1974, Kurihara 2002,, and

Kincaid (1949, cited by Hanna 1966 and Carlton 1979) identified their oyster-associated Japanese limpets as 'Acmea heroldi signata’ which Carlton equated with P. striata, which we have followed here. However, the same P. heroldi signata is now equated with P. signata, a reddish deep-water species in the P. pygmaea complex (Nakano and Ozawa 2005). Patelloida striata, P. pygmaea, and P. signata all occur near Kumamoto, Japan, the source region for the oysters. Patelloida pygmaea occurrs on the Pacific Oyster (Crassostrea gigas) (Nakano and Ozawa 2005), while P. striata seems to be more of an intertidal species (Kurihara 2002). However, in the absence of preserved specimens, the precise identity of these limpets is unknown.


Taxonomic Tree

Kingdom:   Animalia
Phylum:   Mollusca
Class:   Gastropoda
Order:   Patellogastropoda
Family:   Lottiidae
Genus:   Patelloida
Species:   striata


Acmaea heroldi signata (None, None)
Acmaea striata (Quoy & Gaimard, 1834)

Potentially Misidentified Species



General HabitatRockyNone
General HabitatOyster ReefNone
Salinity RangePolyhaline18-30 PSU
Salinity RangeEuhaline30-40 PSU
Tidal RangeSubtidalNone
Tidal RangeLow IntertidalNone
Tidal RangeMid IntertidalNone
Vertical HabitatEpibenthicNone

Tolerances and Life History Parameters

Broad Temperature RangeNoneWarm temperate-tropical
Broad Salinity RangeNonePolyhaline-Euhaline

General Impacts

This species is not currently established in North America.

Regional Distribution Map

Bioregion Region Name Year Invasion Status Population Status
NWP-3b None 0 Native Estab
NWP-3a None 0 Native Estab
NWP-2 None 0 Native Estab
EAS-I None 0 Native Estab
EAS-III None 0 Native Estab
NEP-III Alaskan panhandle to N. of Puget Sound 1924 Def Failed
P293 _CDA_P293 (Strait of Georgia) 1924 Def Failed
EAS-V None 0 Native Estab
SP-XIII None 0 Native Estab
SP-II None 0 Native Estab
EAS-IV None 0 Native Estab

Occurrence Map

OCC_ID Author Year Date Locality Status Latitude Longitude


Abbott, R. Tucker (1974) Amarican Seashells, Van Nostrand Reinhold, New York. Pp. <missing location>

Academy of Natural Sciences of Philadelphia 2002-2016a Malacology Collection Search.

Academy of Natural Sciences of Philadelphia 2006-2014b OBIS Indo-Pacific Molluscan Database.

Carlton, James T. (1979) History, biogeography, and ecology of the introduced marine and estuarine invertebrates of the Pacific Coast of North America., Ph.D. dissertation, University of California, Davis. Pp. 1-904

Hanna, G. Dallas (1966) Introduced mollusks of Western North America, Occasional Papers of the California Academy of Sciences 48: <missing location>

Huang, Zongguo (Ed.), Junda Lin (Translator) (2001) Marine Species and Their Distributions in China's Seas, Krieger, Malabar, FL. Pp. <missing location>

Kurihara, Takeo (2002) Spatial and temporal fluctuation in the density of the intertidal limpet Patelloida striataQuoy & Gamard on subtropical cobbled shores, Journal of Molluscan Studies 68: 79-86

Nakano, Tomoyuki; Ozawa, Tomowo (2005) Systematic revision of Patelloida pygmaea (Dunker, 1860) (Gastropoda: Lottiidae), with a description of a new species, Journal of Molluscan Studies 71: 357-370

U.S. National Museum of Natural History 2002-2021 Invertebrate Zoology Collections Database. <missing description>