Bristle worm - opportunistic or not?

[kviv]

Long story but please bear with me!

I was recently given two clams from a fellow reefer who was taking down his tank. These two were added to the tank without quarantine and joined my existing two clams.

They both settled in well and had good mantle expansion within half a day.

Over the next 2 days I noticed that one of them started to gape and slowly withdrew its mantle even during the day. The shell then appeared to slide off centre so the two sides did not meet.

That night I went home to find the clam dead - flesh gone from shell except foot & fish/other inverts having a good feed.

I removed the shell to look for snails or any other sort of parasite and out came a very large bristle worm (7.5 inches long; almost half an inch wide). I was not able to catch the worm & it went straight under the next clam.

There was no evidence of snails or other parasites when I inspected the shell. Other clams appear ok at this point (several days on).

My questions are:

1. What might have caused the clam to die?
2. Is the worm likely to be the culprit or just an opportunistic feeder after the demise of the clam?
3. Should I be trying to find the worm?
4. Are my other clams at risk?

Other info: 5ft (200gal) tank with 3 x 250W MHs. Tank is a mixed reef and has been running for almost 3 years.

Thanks

Katie

 

[skinz78]

Hello kviv and

To Reef Central

Bristle worms are one of the best clean up crews there is. That is when it comes to the small one's, if that big of one was in my tank I would try my hardest to remove it. I don't think it killed it just getting a free and easy meal.

What are your params?
What fish and inverts do you have?
Can you post a pic of your other clams?
How did you acclimate the new clams?

 

[kviv]

Thanks for the response. If I can find the worm I will pull it out.

My parameters are within normal ranges:

Calcium 400ppm
Salinity 1.026
Alkalinity 2.5 meq/L
Ph 8.2
Magnesium 1280ppm
Temp 26.5 degrees celcius
Nitrates undetectable
Nitrites undetectable
Phosphate usually detectable in low amounts but haven't checked since death of clam
Ammonia undetectable

Sorry for the common names.. I can't find my easy to copy list!

Fish:
Orange shoulder tang
Blue tang
Lawnmower blenny
2 ocellaris clowns
2 pink skunk clowns
Stripped rabbit fish
magenta dottyback
flame angel
solar wrasse

Inverts:
Several large well behaved (uninvited) mantis shrimp
2 banded coral shrimp
Lots of snails
5 maxima clams
H. crispa anemone
various small crabs (hitchhikers)
various worms etc

Corals:
Acro & other SPS
Acans
Sinularia sp.
mix of other corals

I don't have photos on hand but will take some in the next day or so.

THanks again.

 

[kviv]

Add two urchins to that list!

 

[howeroll]

Hey Kviv do you plumb water directly from the GBR to your tank. I would if I lived near the GBR. There is alot of evneous people here in the states that would love to have what you have in your back yard.

 

[kviv]

Not quite howeroll Sydney is a little further south than the GBR. I do however use natural sea water collected from our local beaches. We are very lucky!

A number of the large aquariums (Sydney, Sea World etc) do use water pumped from the harbour but they do not return it without significant filtration, cleaning and possibly even treatment. It is illegal to return livestock to the water so can only imagine there are tight restrictions on water returns.

 

[howeroll]

That's cool and I'm very jealous. I wish to visit the GBR one day. I have heard from other people that live in the outback that the GBR is very protected and you really can't get that close to it.

 

[kviv]

It has been a couple more days than I had anticipated but here are the pics:

 

[salty316]

Kviv, what is that growing on the shell in that first pic?

 

[quicksilverq]

looks like some shrooms