Invasion History

First Non-native North American Tidal Record: 1972
First Non-native West Coast Tidal Record: 1972
First Non-native East/Gulf Coast Tidal Record:

General Invasion History:

Sakuraeolis enosimensis is native to the Northwest Pacific from Mutsu Bay, Japan, south along both Japanese coasts to Korea, China and Hong Kong (Baba and Hamatani 1965; Rudman 2001). In 1972, it was first collected in San Francisco Bay. It is common in the South and Central Bay, but does not occur elsewhere on the West Coast (Behrens 1982; Behrens 1991; Cohen et al. 2005; Cohen and Chapman 2005).

North American Invasion History:

Invasion History on the West Coast:

In 1972, Sakuraeolis enosimensis was collected on marina floats in Pete's Harbor, Redwood City, California. It was associated with colonies of the bryozoans Bugula neritina and Ectopleura crocea, and the hydroid Obelia spp. (Behrens 1982). It has also been reported from San Mateo Bridge Pylons, and from a buoy in the Central Bay. Sakuraeolis enosimensis was most likely introduced with ship fouling or ballast water (Cohen et al. 2005; Cohen and Chapman 2005).


Sakuraeolis enosimensis has a long, slender body, with the tail forming about 1/4 of the body length. Its oral tentacles are long, slender and tapering. The anterior corners of the foot are extended to form horn-like projections. The rhinophores are smooth and shorter than the oral tentacles. The cerata rise from 6-8 arch-shaped pads, in 2-3 rows, except for the posterior two arches, which bear a single row of cerata. The cerata are simple, smooth, and dense, with the longest, in the mid-dorsal region, reaching up to one-half the body length. The animal can reach 45 mm in length, but is more usually 25-30 mm. The color is highly variable, but the basic color of the body is translucent yellow. Sometimes, there are yellow-orange speckles on the head. The liver and its branches usually range from yellow-orange to reddish-brown, but can sometimes be green. The oral tentacles and the tail are marked with an opaque white mid-line, while the rhinophores and cerata have white tips, and the head is also speckled with white. Description based on Baba and Hamatani (1965), Behrens (1982), Behrens (1991), and (Rudman 2001).


Taxonomic Tree

Kingdom:   Animalia
Phylum:   Mollusca
Class:   Gastropoda
Subclass:   Opisthobranchia
Order:   Nudibranchia
Family:   Facelinidae
Genus:   Sakuraeolis
Species:   enosimensis


Hervia enosimensis (Baba, 1930)
Cuthona (Hervia) ceylonica (Baba, 1935)
Hervia ceylonica (Baba, 1933)
Godiva ceylonica (Baba, 1955)
Dondice ceylonica (Abe, 1964)

Potentially Misidentified Species



Sakuraeolis enosimensis is a nudibranch found in harbors, and sheltered coastal regions. Nudibranchs are simultaneous hermaphrodites, and copulate reciprocally or unilaterally. Sakuraeolis enosimensis usually lays its eggs in a tightly coiled spiral, but sometimes as a mass of irregular and segmented strings. Most Northeast Pacific nudibranchs hatch out as planktotrophic larvae, but some have lecithotrophic larvae (Barnes 1983; Behrens 1984; Goddard 2007).

Sakuraeolis enosimensis is found in harbors and sheltered locations warm-temperate regions. In San Francisco Bay, it occurs on dock floats, buoys, bridge pylons, and other fouled strutures . It has been found repeatedly on the introduced hydroid Ectopleura crocea (Behrens 1984; Behrens 2004, in Miller 2014), but the range of its diet is not known. In many nudibranchs which feed on cnidarians, the nematocysts (stinging cells) are ingested, and are then incorporated into the cerata, as a defensive mechanism (Barnes 1983). This is probably the case in Sakuraeolis enosimensis.


Ectopleura crocea

Trophic Status:




General HabitatMarinas & DocksNone
General HabitatRockyNone
Salinity RangePolyhaline18-30 PSU
Salinity RangeEuhaline30-40 PSU
Tidal RangeSubtidalNone
Vertical HabitatEpibenthicNone

Tolerances and Life History Parameters

General Impacts

Sakuraeolis enosimensis is a predator on hydroids, and possibly bryozoans, in fouling communities. However, no ecological or economic impacts have been reported.

Regional Distribution Map

Bioregion Region Name Year Invasion Status Population Status
NWP-3b None 1930 Native Estab
NWP-2 None 0 Native Estab
NEP-V Northern California to Mid Channel Islands 1972 Def Estab
NWP-4a None 0 Native Estab
NWP-3a None 0 Native Estab
P090 San Francisco Bay 1972 Def Estab
NWP-4b None 0 Native Estab

Occurrence Map

OCC_ID Author Year Date Locality Status Latitude Longitude
26781 Cohen, et al. 2005 (SF Bay Area RAS) 2004 2004-05-27 Petes Harbor, San Francisco Bay Def 37.5006 -122.2242
30602 Cohen and Carlton, 1995 1972 1972-01-01 Pete's Harbor, South San Francisco Bay Def 37.5043 -122.2149


Baba, Kikutaro; Hamatani, Iwao (1965) The anatomy of Sakuraeolis enosimensis (Baba, 1930), n. g. (Hervia ceylonica (?) Eliot, 1913) (Nudibranchia-Eolidoidea), Publication of the Seto Marine Biological Laboratory 13(2): 103-113

Behrens, D.W. (1991) Pacific Coast Nudibranchs, In: (Eds.) . , Monterey, California. Pp. <missing location>

Behrens, David W. (1982) Sakuraeolis ensosimensis (Baba 1930) (Nudibranchia: Aeolidiacea) in San Francisco Bay, Veliger 24(4): 359-363

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

Cohen, Andrew N. and 10 authors (2005) <missing title>, San Francisco Estuary Institute, Oakland CA. Pp. <missing location>

Cohen, Andrew N.; Carlton, James T. (1995) Nonindigenous aquatic species in a United States estuary: a case study of the biological invasions of the San Francisco Bay and Delta, U.S. Fish and Wildlife Service and National Sea Grant College Program (Connecticut Sea Grant), Washington DC, Silver Spring MD.. Pp. <missing location>

Cohen, Andrew N.; Chapman, John T. (2005) <missing title>, San Francisco Estuary Institute, San Francisco. Pp. <missing location>

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

Kim, Daemin; Taylor, Andrew T.; Near, Thomas J. (2022) Phylogenomics and species delimitation of the economically important Black Basses (Micropterus), Scientific Reports 12(9113): Published online

Rudman, W. B. 1997-2016 Sea Slug Forum.