Halgerda johnsonorum
Carlson & Hoff, 2000

Order: NUDIBRANCHIA
Suborder: DORIDINA
Superfamily: EUDORIDOIDEA
Family: Dorididae

DISTRIBUTION

Known only from the Marshall Ids.

PHOTO

western seaward reef, Kwajalein Atoll, Marshall Ids. Nocturnally active in caves and ledges at depths of about 10 to 20 meters. Size: preserved length of about 28mm. Note characteristic brown lines on side of foot/body in lower photo. PHOTOS: Scott Johnson.

Very soft and flaccid as compared with the more typical rigid feel of the body of a Halgerda. It is very similar in colour to Halgerda willeyi. The one external difference noted by the authors is that H. johnsonorum has brown spots and lines along the side of the body, under the mantle whereas H. willeyi does not. Carlson & Hoff note differences in the anatomy of the reproductive system and radular morphology.

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

Authorship details
Rudman, W.B., 2000 (June 26) Halgerda johnsonorum Carlson & Hoff, 2000. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/halgjohn

Related messages


Halgerda johnsonorum from Marshall Ids

June 27, 2000
From: Scott Johnson


Hi Bill,

Attached are two photos of the newly described Halgerda johnsonorum. So far we've found these only along Kwajalein Atoll's western seaward reef, where it is nocturnally active in caves and ledges at depths of about 10 to 20 meters. We generally see one at a time, but occasionally run across pairs.

Scott

johnson@kmr.ll.mit.edu

Johnson, S., 2000 (Jun 27) Halgerda johnsonorum from Marshall Ids. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/2624

Dear Scott,
Thanks for the photos. I must say it looks like H. willeyi externally. I will have to look through my notes and photos to see if I have anything like this hiding amongst my H. willeyi. Have a look also at Rie Nakano's Halgerda cf. willeyi from Japan. It looks like there may be a group of black and yellow lined species to match the orange marked species.

There are pages on the Forum for the three new species of Halgerda described in Carlson & Hoff's recent paper:
•Halgerda johnsonorum
•Halgerda batangas
•Halgerda okinawa

Best wishes,
Bill Rudman.

Rudman, W.B., 2000 (Jun 27). Comment on Halgerda johnsonorum from Marshall Ids by Scott Johnson. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/2624