Hancockia californica

Photo at left courtesy of Jim Lance. Bahia de los Angeles, Baja California
Photo at right courtesy of Mary Ellen Hill and Caroline Schooley


Hancockia californica Macfarland, 1923

Not very common, and certainly one of the strangest nudibranchs on the California and outer Baja California coast is Hancockia californica . Little is know about this strange little Dendronotacean with the weird palmate cerata, having from 4 to 16 digitations on each ceras. There is a similar process to each side of the head, also. To add to the uniqueness, the rhinophores are a fluted pulpit shape.

The color varies quite a bit from the mottled specimen from Baja California to much lighter colored specimens like this one collected in summer 2002 at Glass Beach in Fort Bragg, by Mary Ellen Hill and Carolyn Schooley, at the northernmost extent of its known range.

The genus is named in 1872 for British biologist Albany Hancock and the species name given by MacFarland denotes its type locality of California. Hancockia californica is quite small reaching only about 15 mm in length and is currently known from Punta Abreojos to Fort Bragg, California. Other species in the genus are Hancockia uncinata (Hesse, 1872), H. burni, Thompson, 1972, and H. ryrce, Marcus 1957.

Hancockia uncinata (Hesse, 1872) is known from the Bay of Biscay in Great Britain to St. John's Point, Co Donegal, NW Ireland; Mediterranean France; Spain; and Naples.

Dave Behrens
Danville, Calif
Jul. 2003



Mary Ellen Hill and Caroline Schooley

The "Mendocino Nudibranchs " exhibit that Mary Ellen Hill & Caroline Schooley assembled a few years ago has been shown several times in Mendocino and Fort Bragg. It will be on display all summer (weekends only) as part of the marine science exhibit at Point Cabrillo lighthouse, between Mendocino and Fort Bragg. Photos of about 3 dozen species, plus a bit of text about biology & ecology

For more information contact Caroline at schooley@mcn.org


Taxonomic information courtesy of:


David W. Behrens

Author: Pacific Coast Nudibranchs
Co-Author Coral Reef Animals of the Indo Pacific
Proprietor of Sea Challengers Natural History Books !

Send Dave mail at dave@seachallengers.com


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