E-Fauna BC: Electronic Atlas of the Wildlife of British Columbia

Cucumaria frondosa japonica (Gunnerus, 1767)
Black Sea Cucumber
Family: Cucumariidae
Photo of species

© Neil McDaniel  Email the photographer   (Photo ID #15848)

E-Fauna BC Static Map
Distribution of Cucumaria frondosa japonica in British Columbia
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Species Information

Click on the image below to view an expanded illustration for this taxon. If more than one illustration is available for a species (e.g., two subspecies may be illustrated) then links to the separate images will be provided below.

Cucumaria frondosa japonica is the largest of the Cucumaria species on our coast. It has the typical Cucumaria shape, but has a grey to black body. The tentacles and mouth region can be quite colourful, with areas of white or red. When dredged or disturbed it resembles a grey football. It is gigantic compared to other species of Cucumaria on this coast. It can attain a length of 30 cm and longer, depending on its state of relaxation. The contractile tube feet are in five rows. The 10 equal-sized tentacles are black and bushy when extended.

Skin ossicles: quite variable and usually cannot be found in large specimens; in small specimens, elongate perforated plates with large holes, sharp bumps on the surface and scalloped margins. In the introvert, the ossicles are larger and more complex.

Similar Species

Cucumaria frondosa japonica resembles Cucumaria miniata in general body form, but the former is usually larger and darker. A juvenile C. f. japonica might be confused with C. miniata; however, the latter is usually orange. Cucumaria frondosa is a common sea cucumber on the east coast of North America. Cucumaria japonica is the closely related species in Japanese waters of the northwestern Pacific. Some consider japonica to be a subspecies of frondosa, but there is presently no agreement. The specimens on this coast seem to be intermediate in many characters, hence I have used the subspecies designation. However, Dr V. Levin from Russia has looked at our specimens and has concluded that they are not C. f. japonica and suggests there may be more than one species. Until the status of this species is resolved, I shall use the name C. f. japonica to indicate its close relationship to C. frondosa and C. japonica.



frondosa = full of leaves
japonica = refers to Japan

There are no studies on the biology of this subspecies on the west coast of North America. Because it is so closely allied to C. frondosa on the east coast, the biology of that species could be used as a guide (see Jordon, 1972).


Cucumaria frondosa japonica is uncommon in the south. It is usually dredged from sand or gravel, but can also be collected by scuba from rock substrata. It has been reported from shallow water in Burke Channel in large numbers on a rocky substratum.

Status Information

Origin StatusProvincial StatusBC List
(Red Blue List)
BC Ministry of Environment: BC Species and Ecosystems Explorer--the authoritative source for conservation information in British Columbia.

Additional Range and Status Information Links

Additional Photo Sources

General References

Recommended citation: Author, Date. Page title. In Klinkenberg, Brian. (Editor) 2021. E-Fauna BC: Electronic Atlas of the Fauna of British Columbia [efauna.bc.ca]. Lab for Advanced Spatial Analysis, Department of Geography, University of British Columbia, Vancouver. [Accessed: 2024-02-26 12:00:28 AM]
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