Pleurobranchaea brockii - feeding observation

November 6, 2006
From: Paul Humann

Dear Bill,

I photographed the attached Pleurobranchus off Pantar Indonesia, on a night dive in Feb. 2006. I was in 10 m of water and the Pleurobranch was
about 5cm long. It was crawling about the sand eating small tube-dwelling anemones (Ceriantharia). It would crawl to very near the anemone then lift its hood like mouth coming down over the anemone (as can be seen in the picture) before the anemone could retract. I watched this guy eat at least 4-5 of these tube anemones, no question in my mind that they were a favorite food source. Its "pounce" on them was so fast that the picture I sent was the only picture I got of it actually coming down on the anemone.

I've checked all my reference sources and all the pleurobranchs you picture on the forum, but cannot come up with an identification of the species. Do
you know what species it is? I appreciate any assistance you can give.

Keep up the good work and best regards,
Paul Humann

Humann, P., 2006 (Nov 6) Pleurobranchaea brockii - feeding observation. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

Dear Paul
This is Pleurobranchaea brockii - the feeding observation is very interesting. As you'll see on te Forum this species has been reported feeding on cephalaspidean bubble shells, and larger animals are cannibalistic. This is the first record of it feeding on sea anemones, but as anemones don't have hard parts they are not usually identified in stomach contents. We don't know much about feeding in pleurobranchs, but one species of Pleurobranchaea, P. maculata is reported to feed on anemones.

It's possible that all species of the genus are opportunistic predators, but as many potential prey do not have hard parts, we will only discover what they really eat through the accumulation of observations such as yours

Best wishes,
Bill Rudman

Rudman, W.B., 2006 (Nov 6). Comment on Pleurobranchaea brockii - feeding observation by Paul Humann. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

Related messages

  1. Pleurobranchaea brockii from Mozambique
    From: Valda Fraser, May 30, 2008
  2. Pleurobranchaea brockii from Hong Kong
    From: Jasmine Ng , February 3, 2005
  3. Pleurobranchaea from the Philippine Islands
    From: Erwin Koehler, May 21, 2003
  4. Pleurobranchaea brockii? from the Philippines
    From: Erwin Koehler, November 30, 2002
  5. Daytime activity in Pleurobranchaea brockii
    From: Ákos Lumnitzer, January 10, 2002
  6. Re: Pleurobranchaea brockii from Sydney
    From: Kathe R. Jensen, April 1, 2001
  7. Re: Pleurobranchaea brockii from Sydney
    From: Erik Schloegl, March 31, 2001
  8. Pleurobranchaea brockii from Sydney
    From: Erik Schloegl, March 29, 2001

Show factsheet and all related messages