January 9, 2003
From: Brett Lynch
Dear Dr. Rudman,
I have a reef tank for almost ten years now and as long as i can remember I've had these black seaslugs. They grow to about an inch and have a white stripe down their back and can cover it up with their frilly black cape?. They have two prominent anttenae. They don't feed on my corals except a pink Pocillopora (sps) which they devoured in one night. Most of my corals are LPS'S and are from Bali, Indonesia area. The black slugs readily spawn. All 15 spawn at once right after the white lights goes out. These slugs have a cartilige hardness I can feel when I remove some due to their proliferation, weird, like squid bones?? They only come out at night and wait under rocks till the brightest lights go out. When I ask my dealer he explained that they where in the snail family, but I can't find any information on them. Also I have no algae problems since my guests have had a strong hold?
From your excellent description I am certain your animals are a snail called Scutus If you have a look at the Fact Sheet you will see the white line you describe is in fact part of its flattened shell. I'm glad to hear that since you've had these beasts you have no algal problems, because if you look at the earlier messages on the page from other aquarium keepers, you will see I suggest that Scutus might help with unwanted algal film on the glass and rocks. I am a bit surprised by your comment about them eating a coral colony. Is it possible the colony was already dead and they were eating the algal film which would grow quite quickly on the skeleton?
I am interested in your comment on spawning. Does that mean you have seen them releasing eggs and sperm into the water? Is it a milky cloud? You'll see I have just recently explained how they spawn in answer to another message.
Re: Black sea slugs in reef tank
From: Mike Duggan, February 8, 2008
A Black Sea Slug in an Aquarium
From: Sampo Tiensuu, December 12, 2007
Found what I believe to be a Sea Slug or Snail in my Tank
From: Chad Naujoks, November 28, 2007
Re: Scutus reproduction
From: Aubrey, May 18, 2007
Re: Scutus reproduction
From: Matthew A. Clarke, February 9, 2007
From: Rob Wedin, October 20, 2005
Black slug thing in aquarium
From: Kristina Mahan, October 8, 2005
Scutus snail - in aquarium
From: L. Whyte, September 9, 2005
Black And white Nudibranch?
From: Colin Winkelmann, August 17, 2005
Re: Is Scutus 'Reef safe' ??
From: Kingston Wong, March 9, 2005
Is Scutus 'Reef safe' ??
From: Kingston Wong, March 5, 2005
3 Scutus in my tank
From: Catalina Pampin, February 23, 2005
Re: Reproduction of Scutus sp.
From: Rob, November 14, 2003
Identification of a Black Slug
From: Elvis, August 11, 2003
Scutus in aquarium
From: Charles S. Thompson Jr., February 4, 2003
Scutus in aquarium (2)
From: Nathan Gaub, February 4, 2003
Re: Black seaslugs in reef tank
From: Brett T Lynch, January 11, 2003
Reproduction of Scutus sp.
From: Timothy D. Loyd, January 7, 2003
Sea slug in my tank?
From: Daniel R, October 1, 2002
Another Scutus in an aquarium
From: Tae Kim, September 27, 2002
Scutus - Thanks
From: Becky, April 25, 2002
Thanks Dr Rudman
From: Pippa Styles, March 20, 2002
Another Scutus in live rock
From: Becky, March 5, 2002
Trying to ID black slug
From: Mark Conley, November 20, 2001
Re: Mystery black Sea Slug
From: John Strawn, November 8, 2001
Mystery black Sea Slug
From: John Strawn, November 7, 2001
Re: Aquarium mystery
From: Jay Rundle , September 1, 2001
Can you identify this Sea Slug?
From: Jay Rundle, August 31, 2001
Mystery Sea Slug is Scutus
From: Marve Wiessner, June 12, 2001
Flatworm? Scutus? I.D. Help Needed
From: Matt Anderson, April 21, 2001
Is this some slug or a limpet?
From: Kristen Chinn, December 30, 2000
Help with ID.. aquarium mystery
From: Tim Merkel, December 28, 2000
re: Black nudibranch
From: Gareth Trinko , September 16, 2000
From: Gareth Trinko , September 15, 2000
Solid Black Sea Slug
From: Timothy Loyd, August 16, 2000
From: Kelly Greco, December 11, 1999
What is Scutus?
From: Deepak G Sarin, June 20, 1999