Halgerda okinawa

Photo couresty of Marc Chamberlain
Lembeh Straits, Indonesia

Halgerda okinawa Carlson & Hoff, 2000

The last 2-3 years have been a hay day for the description of new Halgerda's . Between the Clay Carlson and Patty Jo Hoff and the Shireen Fahey and Terry Gosliner teams, I lost count at about 16 or more newly named species. Branching buddy Bob Bolland first collected this species back in 1995 in 175 feet of water off Seragaki, Okinawa, his favorite dive site. Since that time he has collected it, one of twelve species of Halgerda found in Okinawa, often.

Halgerda okinawa was depicted in Coral Reef Animals of the Indo-Pacific on page 160 as Halgerda sp. from the Lembeh Straits of Indonesia. Marc's fantastic photo shown above is a spectacular example of the species, from this locality. It has also been documented from the Straits by photos taken by Carine Schrurs and Constantinos Petrinos. My good buddy "Con" reports that "During a dive at a dive site called NUDI RETREAT we located several Halgerda okinawa within an area of 10 meters at a depth of 42.5 meters."

As Bill Rudman points out on the Sea Slug Forum that the Indonesia specimens match the color of the Okinawan type specimens except for the absence of the black lines on the ridges. He suggests that the broken black rings near the mantle edge, which are so well developed in this Indonesian animal, seem to definitely link it to the Okinawan animals, one of which shows markings which could easily be derived from these rings.

Halgerda okinawa is a large species reaching over 125 mm in length. On Bob's Okinawan Slug Site , he has added a page with photos of the holotype and paratypes . Comparing the photos from Indonesia with Bob's page shows the variation in this species quite well.

Reference materials (for the hard cores):

Carlson, C.H. & P.J. Hoff. 2000. Three new Pacific species of Halgerda (Opisthobranchia: Nudibranchia: Doridoidea). The Veliger 43(2):154-163.

Fahey, S. J. & T. M. Gosliner. 1999. Preliminary Phylogeny of Halgerda (Nudibranchia: Halgerdidae) from the Tropical Indo-Pacific, with descriptions of three new species. Proceedings of the California Academy of Sciences 51(11): 425-448.

Gosliner, T.M., D.W. Behrens & G.C. Williams. 1996. Coral Reef Animals of the Indo-Pacific. Sea Challengers, Monterey, California.

Dave Behrens
Danville, Calif
Jan 2004

Marc Chamberlain is by vocation a neurologist and by avocation a wildlife photographer. He enjoys traveling during which he is always toting cameras. His diving holidays have been to the Carribean, up and down the west coast of the Americas and throughout the Indo-Pacific. His photographs have appeared in numerous magazines including: National Geographic; International and National Wildlife; Ocean Realm; Outside; and various Cousteau Society publications. Marc has collaborated on several books including Nudibranchs of the Pacific Coast. Marc was also San Diego Underwater Photographic Society Photographer of the Year six times during the time he lived in the San Diego County area. Marc has participated in thirteen consecutive San Diego Underwater Society Film Festivals which has to be a club record!

Send Marc mail at chamberl@usc.edu

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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