Friend or foe!??

greenninja19

greenninja19

New member
Yea the zoa was happy and open yesterday and as you guys can see its not now

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Herbie

Herbie

Banned
greenninja19 said:
Pulled him out and he is in a cup and that's where he shall stay

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A Fowler, puffer, or mantis owner might want the bugger, but they are not safe even in my sanctuary. They're only good if you have a nuisance paly problem.
 
Lynn Z

Lynn Z

New member
Yep, that's a foe alright. It's a sundial snail, genus Heliacus that belongs to a family of cnidarian predators called Architectonicidae. The two most commonly seen hitchhikers are probably Heliacus areola and Heliacus variegatus. The shape (cone-like with a flat bottom), "pagoda-like" operculum ("trap door"), and checkerboard pattern in shades of white/cream and browns to black are typical. Of note is that these are small snails (< 1" as adults) but those seen as hitchhikers are generally younger and much smaller (< 1/4"), so they can be a challenge to find. Also, I say "probably" (regarding species) because there are many in this genus that fit the above description. It’s the details of shell morphology that make all the difference - and they can be slight. Compounding the issue is the fact that each species can vary to a surprising degree, in height, umbilicus width, color, etc. Needless to say, it makes identifying, with just a single photo, a serious challenge.

Heliacus spp. are mostly nocturnal and feed on the tissues of Zoanthus and Palythoa spp. by means of everting their proboscis and chewing away (always reminds me of the jaws that came out of that horrible creature in Alien). By the way, I've read that these snails may also feed on stony corals but I haven't been able to confirm it. I know it happens in other genera (Psilaxis and Philippia) but it's up in the air with Heliacus. Here's something weird and interesting: the mouths of these snails have a sort of reinforced/tough lining that protects it from the nematocysts/stinging cells of the prey coral.

  1. Signs of infestation include closed and/or disappearing polyps and upon close inspection, small holes.
  2. Check the colony immediately for any obvious snails (or Nudibranchs!), then again, after the lights have been out for at least an hour. Use a flashlight and check around the base of each polyp (use tongs/forceps or tweezers to remove any snails present).
  3. Repeat nightly checks for several days
  4. Watch colony for any further signs of predation and if so, go back to #2.

Here are a couple of links with photos:
http://www.wildsingapore.com/wildfacts/mollusca/gastropoda/architectonicidae/variegatus.htm
http://www.marinelifephotography.com/marine/mollusks/gastropods/sundials/heliacus-areola.htm
 
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