Scissortail gobies missing 2 out of 3

Hello,
A few months ago, my hubby got me 3 scissortail gobies, which I love. I was about to put the clowns in to the 40 frag tank in my son's room, when all of a sudden about a week ago one of the scissortails came up missing. All 3 went to bed in their burrow and only 2 came up in the morning. I can see with a flashlight into part of the burrow. I couldn't find any evidence of a body. Then 2 days ago another one of the scissortails is gone. POOF. Again no signs of a body. The one left is getting picked on here and there by the 6 line and somewhat by the clowns.

My parameters are Ammonia, Nitrites, Nitrates, all 0. pH 8.0. Salinity 1.025. I have been topping off regularly and doing water changes every other week.

All the fish looked healthy. Other fish are my yellow tang, kole tang, 6 line wrasse, pair of b/w clowns, coral beauty, and 3 scissortail gobies. We got rid of 2 fish that had been in there my starry blenny because he has practically killed my kole tang. I think she will recover. My dottyback because she has an awful personality.

My inverts are yellow brittle sea star, serpent sea star, short spine urchin, little tuxedo urchin, and a sally lightfoot crab as well as little hermits and snails. I have a few bristleworms. One pretty big one, I can't seem to catch.

The yellow brittle star, 6 line and scissortails have all slept under the same rock for awhile with no issues. I have no idea. What could have happened?

Help would be welcome.

I'm sorry to hear about the losses (and about the starry blenny!)

I have a few thoughts, though don't know if any are going to be on target. The first is whether they could have jumped? (I don't remember if your tank is covered or not). The second is that the wrasse might be beating up on them too much. The third (and what I think might be most likely) is that the yellow brittlestar might in fact be a variation of the green brittlestar and might be preying on them, especially if they sleep in the same place....

FishyReef said:

I'm sorry to hear about the losses (and about the starry blenny!)

I have a few thoughts, though don't know if any are going to be on target. The first is whether they could have jumped? (I don't remember if your tank is covered or not).
Yes it is covered and they are not in the overflow, which is slotted and I guess they could possibly squeeze through but I don't think so.

The second is that the wrasse might be beating up on them too much. He never bothered the scissors until their was just 1. He sleeps on other side of the hole. Could he be in danger if its the brittle?

The third (and what I think might be most likely) is that the yellow brittlestar might in fact be a variation of the green brittlestar and might be preying on them, especially if they sleep in the same place....

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I NEVER would have bought him had I had even an inkling of an idea that he was a variation of the green. His cap is size of a nickel but has grown from a dime since December. This fish started disappearing a week ago and several days apart so that makes sense.

The Sallylight foot could also be a culprit. Although I have never had a issue with them they are not really reef safe especially with smaller fish. Sorry for your losses.

Generally if a brittle or serpent star eat anything big you will see bulging in their disk for several hours afterward....are there ANY openings in the top of the tank, even as big as the fish itself...they are notorious jumpers and can find the tiniest opening....do you have cats or other pets that would have...well....destroyed the evidence?

I only trust serpent stars....

I yanked my star from the DT and plunked it in the sump on Tuesday since I suspect it's been killing my livestock. It seemed to be fine in the old tank but there was more algae in there. Since the move to the new tank I've caught harassing corals, fish, even clinging to a hermit last week, We'll be trading her in on Saturday

salt_for_brains said:

The Sallylight foot could also be a culprit. Although I have never had a issue with them they are not really reef safe especially with smaller fish. Sorry for your losses.

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We have a sharknose goby like a neon goby and he's fine. I really don't think its the Sally. We had a nasty emerald.

MitchReef said:

Generally if a brittle or serpent star eat anything big you will see bulging in their disk for several hours afterward....are there ANY openings in the top of the tank, even as big as the fish itself...they are notorious jumpers and can find the tiniest opening....do you have cats or other pets that would have...well....destroyed the evidence?

I only trust serpent stars....

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I know how full their cap can be looking like they are going to explode. I have seen our serpent star after feeding silversides. The brittle stays hidden. But since he sleeps right there I suspect it could be him. I haven't seen him except tenacles. I will get him out in the morning. He can go in the quarantine tank til Saturday and we will take him to pet store for store credit.

Angelajean said:

We have a sharknose goby like a neon goby and he's fine. I really don't think its the Sally. We had a nasty emerald.

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Ok, just wanted you to know as juvi's they are more into algae but as the grow to adult they become more lethal carnivores and have the ability to catch, kill and eat fish.

I tried to do some reading up on brittlestars awhile back and the species that is the predatory green brittles can also come in slightly varied brown and yellow coloring. I wish I could find the info I found, that's the only reason I mentioned it. I have no idea if that yellow one is indeed the same species or a related species, but I think its a good bet. I also think the sixline is probably safer since they move so fast and are pretty agile swimmers, but you never know, especially since the brittlestar can be active and hunting at night when the fish sleep.... I'm hoping someone else with more experience can chime in on this!

Scissortail goby is alive this morning. I removed the brittle seastar into our QT. I am wondering if I should consider getting him a friend or 2. I would put him along with the other NEW fish in the 40 gallon QT for the time being then add them as a group. Our family was discussing if we need a scissortail or if we could get a blue grudgeon or zebra barred dartfish.

Saltwater Aquarium Fish for Marine Aquariums: Blue Gudgeon Dartfish

Saltwater Aquarium Fish for Marine Aquariums: Zebra Barred Dartfish

Or do we need to stick with scissortail goby?

Thanks for the help.

There are mixed theories about the darts....I always thought they were good schooling fish but another experienced hobbyist said if you have more than one of a species they will develop feeding dominance and one will eventually starve the others out...I think that's hogwash myself, but it is something to consider. I'm more prone toward a little school of one species, but the friend's logic would say go with the other types....

I guess you should just go with the look you want in the tank....