Boreoberthella californica (Dall, 1900)

Description

An oval, flattened sea slug a few centimetres long. It is a side-gilled slug (pleurobranch): the dorsal mantle covers the body, and a gill lies on the right side between the mantle and the foot. The body is white to brown, scattered with small white spots, and the mantle margin is edged with a white band; a thin flat shell is retained internally.

Distribution

Northeastern Pacific, from Ventura County in southern California, through Mexico to Panama and the Galápagos Islands. It lives in the subtidal zone. The species was originally described from San Pedro, California.

Etymology

The specific epithet californica means “of California,” after the type locality.

Remarks

A sponge feeder. It was long treated as a single wide-ranging North Pacific species, but a 2020 study showed that northwestern Pacific animals (Japan, Korea and Russia) belong to a separate species, Boreoberthella chacei; B. californica in the strict sense is restricted to the southern part of the northeastern Pacific.

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References

• Pleurobranchus californicus n.sp., Dall W.H. (1900). A new species of Pleurobranchus from California. The Nautilus. 14(8): 92-93.
• Berthella californica, Ghanimi H., Goddard J.H.R., Chichvarkhin A., Gosliner T.M., Jung D.-W. & Valdés Á. (2020). An integrative approach to the systematics of the Berthella californica species complex (Heterobranchia: Pleurobranchidae). Journal of Molluscan Studies. 86(3): 186-200.
• Berthella californica, Behrens D.W., Hermosillo A., Fletcher K. & Jensen G.C. (2022). Nudibranchs & Sea Slugs of the Eastern Pacific. Molamarine.