A case of disappearing shrimp. Help!!!

[tzylak]

Until recently, I had the skunk, peppermint and fire shrimp in my 50g hex.
A month ago I added a 5 inch Maxima and an 8 inch green Serpent Sea Star.
Yesterday I noticed that my aiptasia is out of control and my skunk and peppermint are GONE!!
I doubt that the Maxima had anything to do with the disappearances.

1. Is it possible that the Serpent ate my two shrimp?
2. If so, then is the fire shrimp next on the menu??
3. Are any other CUC in danger?
4. Are the fish in danger of being eaten??

HELP!!

Tank specs:
Fish: Ocellaris Clown, B&W Clown, Firefish Goby, 6-Line Wrasse, Midas Blenny, 3 Banggai Cardinals, Cleaner Shrimp(???), Fire Shrimp, Banded Coral Shrimp, 8" Serpent Sea Star, Peppermint Shrimp(????), Bristle Worms and CUC.
Reef: 150 lb. Sand, 70 lb. Rock, 10" Frog Spawn, 5" Maxima, Button Polyps, 3" Hammer, Mushrooms, Kenya Trees, Brain, Leather Toadstool, Cheato and one aiptasia
Tank: 50g hex with overflow, 23 gal sump with DSB, 2x Rio 3100 return pumps, 2x15" power compact 10K, 2x 50/50, 1x actinic, 1x deep blue LED strip, chiller 650, heater 100W, skimmer 65.
I got the tank on 7/18/2014 but it has been established for over 20 years!!
I do semi-weekly water test and weekly 5g changes.
pH 7.8-8.1, NH3 0, NO2 0, NO3 0-1, PO4 0, Ca 360-400, Alk6-7, 77-79F, Mg 1340-1420 sg 1.022-25
23 sec. video: https://www.dropbox.com/s/2s5ik52vqmwh4w1/151019 Aquarium.wmv?dl=0

 

[MondoBongo]

i would bet on the serpent star being the issue.

 

[username in use]

First of all Kudos :thumbsup:, that is a great looking Hex Reef. They are tough tanks to work with and that is a really nice mixed reef you have going there.

Both the Coral Banded Shrimp and the Serpent Star can in theory be aggressive. If all the shrimp had been together for a long time before the addition of the star than that is most likely your culprit. But I wouldn't rule out the CBS.

Are you sure there are no other crabs of any kind in that tank?

 

[SNAKEMANVET]

I would say the green serpent star is the culprit.

 

[tzylak]

I must add that I spot feed the Serpent with an Advil-pill-sized chunk of shrimp every-other day. -It should not be hungry.

 

[TONY_C]

Well, you know for sure that your Sea Star does like the taste of shrimp.

 

[snorvich]

I must add that I spot feed the Serpent with an Advil-pill-sized chunk of shrimp every-other day. -It should not be hungry.

You have your culprit.

 

[tzylak]

Ok, so does anyone have any experience with the extent of Serpentine's appetite? -Eating other CUC? Fish?
The creature is cute, but in a gross/scary way. I'd like to keep it, BUT NOT at the cost of the rest of the creatures.

 

[frey]

yep, my cute little serpent start got bigger and bigger, then my gobies starting going missing. Moved the serpent to the sump added another gobie, no issues since. I have read since that they are pretty good predators. if they can nab it, they will at least try to eat it.