Nudibranch eggs on a fish

August 4, 2004
From: Chris Grossman

On Friday July 16, 2004 I was diving at Begg Rock a pinnacle 10 miles Northwest of San Nicolas Island, California. On the third dive I encountered a California Scorpionfish (Scorpaena guttata) with nudibranch eggs on it's side. I have never observed that before. I don't know what type of nudibranch left the eggs, but I thought it was interesting since I have only seen eggs attached to hard substrates or plants in the past.

Alan Grant comments:
'My guess is that it is Hermissenda, but wait until the experts weigh in with their opinions. Since the Scorpion fish waits in ambush to feed and is relatively sedentary, it's not surprising that a nudibranch might crawl up on it's body, start laying eggs, and then go along for the ride when the fish moves'.

Chris Grossman

Grossman, C., 2004 (Aug 4) Nudibranch eggs on a fish. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

Thanks Chris,
The eggs could easily be those of Hermissenda. As Alan Grant notes, nudibranchs are certainly found crawling over fish, such as scorpaenids, which sit in one spot for considerable periods. I must say I have never seen one with an egg ribbon attached.
Best wishes
Bill Rudman

Rudman, W.B., 2004 (Aug 4). Comment on Nudibranch eggs on a fish by Chris Grossman. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

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