How much food does a giant bristleworm need?

[Tired]

I've been trying to dial in a Plank auto-feeder so my fish get fed multiple times a day, and I didn't realize at first that I was putting too many sinking pellets (for a decorator crab) in there until I saw the enormous bristleworm I'd inadvertently created, living under the feeder. I redid my rockscape yesterday and pulled the bristleworm out, and now have it in a cup so I can consider whether I want to put it back in.

This thing's about as big as this species can get, I think. It's definitely the regular kind, pink with white bristles, just grown huge. Eight inches long and nearly half an inch across. I'm not sure if I want to keep it- it's cool, but I don't know if I want to keep feeding it, or how much bioload it might have.

I'm aware this might be a question no one knows the answer to, but how much food does a worm like this need?

 

[vetteguy53081]

I've been trying to dial in a Plank auto-feeder so my fish get fed multiple times a day, and I didn't realize at first that I was putting too many sinking pellets (for a decorator crab) in there until I saw the enormous bristleworm I'd inadvertently created, living under the feeder. I redid my rockscape yesterday and pulled the bristleworm out, and now have it in a cup so I can consider whether I want to put it back in.

This thing's about as big as this species can get, I think. It's definitely the regular kind, pink with white bristles, just grown huge. Eight inches long and nearly half an inch across. I'm not sure if I want to keep it- it's cool, but I don't know if I want to keep feeding it, or how much bioload it might have.

I'm aware this might be a question no one knows the answer to, but how much food does a worm like this need?

Theyre scavengers. They take what they get. You dont want to purposely plant food for them which if uneaten can potentially foul your water
From looks of this worm, Its not short of food

 

[twentyleagues]

While bristle worms are not detrimental to a reef ( in fact good cuc) if I find them that big I will remove them. If you have one that size you have lots of smaller ones.

 

[Doctorgori]

I usually thin the herd at every connivence….
…no. love for worms per se but I will bother with a humane trip to the freezer

 

[Tired]

Right, I know they're scavengers, and this one was definitely getting enough to eat. Thing is, I'm adjusting the auto-feeder, so it won't be dropping excess food by the worm's home. If I do keep this, I don't want to starve it, so I'm trying to figure out how much food it would need.

Believe it or not, I don't actually (appear to) have a lot of smaller ones. I have about three smaller ones that I've seen, and that's at peak extension of everything reaching out of the rock for food. None under the rockwork except this one, I know that much. I also have at least three reticulated brittle stars, which, though not very large, are probably eating some of the food that would otherwise be turned into more bristleworms.

I'm not sure freezing is a humane way to kill these. If you don't have any clove oil to use as an alternative (and, IMO, clove oil should be in everyone's fishkeeping cabinet, for moribund fish if nothing else), refrigerating them for a few hours first, to try to render them less aware or entirely unaware first, is probably a good idea.

 

[exnisstech]

Feed the fish and the worm will get food. I have no problem with them but it's not something that I would feed directly and I don't think there is a reason to do that. I probably have hundreds in my tank and they eat what they scavenge. Mine are nocturnal and the bottom is covered in bristle worms when lights are out. You most likely have others but they are hidden. I find some anytime I move rocks or coral that are on the bottom but I never see any during the day.

EDIT : I agree freezing is not really humane. I have other methods that are quick and efficient but I won't discus them here as people tend to get offended too easily these days and think I'm cruel. I have used clove oil as well for fish that are small enough for that method.

 

[Reefkeepers Archive]

Keep it! That's a cool find!

 

[Tired]

I have only a few small fish. This guy got big because I formerly had sinking pellets in the feeder for a decorator crab, and I had too many pellets, resulting in a lot left over. The crab has died, so I no longer have any pellets, let alone any left over. I'm pretty sure I'm gonna have to deliberately feed this guy. Unless they can shrink when they aren't getting fed enough.

I rearranged my entire aquascape two days ago. There were zero bristleworms underneath, except this single huge one.

Ah, the smashing approach? Sounds awful, but obliterating something's brain in one fell swoop means it can't suffer. It's as humane as something like shooting a deer in the head. I used clove oil to euthanize some fireworms that came in on the rock, and it seemed to work all right, as long as it was added properly slowly- I didn't see any faster movement, squirming, or any other indicators of distress as the oil mixture was slowly going in.

Keep it! That's a cool find!

I'm very tempted to. I wonder if I can reliably lure it out with reef roids or something similar to show it to people? I just need to figure out how much it needs to be fed.

 

[AydenLincoln]

KILL IT WITH FIRE!! Is always my response!

 

[tautog83]

You have hundreds of worms you can bet on it

 

[Tired]

They must be invisible, then, because I saw none under the entire rockscape, there are never any when I move plugs on the sandbed, I only see threeish when I put in strong-smelling food, putting the rocks on a tray with some water didn't shuck any out, and I don't see them at night.

I know there are a lot of people who don't realize how much life is in their reef because they aren't familiar with how to look, but I am actually looking. More than I'm seeing, sure, but not hundreds. Otherwise I'd probably have a dozen fairly large bristleworms instead of one huge one.

 

[ISpeakForTheSeas]

I just need to figure out how much it needs to be fed.

I've only read through a handful of polychaete aquaculture articles so far, but from what I've read, aiming to feed ~4 % of the worm's bodyweight (the most recent study I read used wet weight, but dry would probably work fine too) per day.

Using the worm Hediste diversicolor for a weight estimate based on the size you've listed for the worm, I'd guess, your worm is probably around 500mg by wet weight. That said, there are scales for miligram measurements you could use if you want to be more precise.

 

[Tired]

Ah, that's very helpful, thank you! I guess I'd have to figure out what the dry food would hypothetically weigh if wet, since some of the wet food weight is water, but that's doable.

Did they say whether that amount is to maintain them at the current size, or to grow them? Since bristleworms seem to be an organism whose size (within a certain range) is largely controlled by access to food.

We have a scale that can measure in grams and tenths of grams. I can go try to weigh this guy in a bit of water, hang on.

 

[The_Paradox]

Ah, the smashing approach? Sounds awful, but obliterating something's brain in one fell swoop means it can't suffer. It's as humane as something like shooting a deer in the head. I used clove oil to euthanize some fireworms that came in on the rock, and it seemed to work all right, as long as it was added properly slowly- I didn't see any faster movement, squirming, or any other indicators of distress as the oil mixture was slowly going in.

Just gonna leave this here and walk alway.

 

[ISpeakForTheSeas]

Ah, that's very helpful, thank you! I guess I'd have to figure out what the dry food would hypothetically weigh if wet, since some of the wet food weight is water, but that's doable.

Did they say whether that amount is to maintain them at the current size, or to grow them? Since bristleworms seem to be an organism whose size (within a certain range) is largely controlled by access to food.

We have a scale that can measure in grams and tenths of grams. I can go try to weigh this guy in a bit of water, hang on.

That's the amount to grow them, breed them, and maintain them.

 

[Tired]

I remembered these guys are okay out of water for a bit, so I poured out all the water, very quickly weighed him in the cup (34g), refilled his cup, weighed an empty cup (16.5g), and got what should be about the right number. 17.5 grams of worm! 17,500mg.

As to food weight, I remembered the Avast Marine website talks about measurements of their dried food compared to frozen foods.

The Plank will dispense 0.07g of Reef Jerky in 30 seconds, or 0.14g/min. That means 1 ml (or 1cc) of Reef Jerky per minute. In terms of frozen cube equivalent, this means about 3 minutes of Plank runtime will dispense roughly 1 "cube" (by volume, not weight) of Reef Jerky.

I could probably base something off of this. Or I could weigh a small portion of wet frozen food, let it dry completely out, and then weigh it again. I imagine 1 gram of dried fish food is about as much as 1 gram of pellet food, since pellet food is just dried food ground up and stuck together.
4% of this guy's weight is 0.7g. If I can work out how much 0.7g of wet food weighs when dry, that's probably how much pellet food he'd want, assuming the math works out for this species.

How do I tell if a worm isn't getting enough to eat? Will he come out and roam around looking for more?

 

[twentyleagues]

I remembered these guys are okay out of water for a bit, so I poured out all the water, very quickly weighed him in the cup (34g), refilled his cup, weighed an empty cup (16.5g), and got what should be about the right number. 17.5 grams of worm! 17,500mg.

As to food weight, I remembered the Avast Marine website talks about measurements of their dried food compared to frozen foods.

I could probably base something off of this. Or I could weigh a small portion of wet frozen food, let it dry completely out, and then weigh it again. I imagine 1 gram of dried fish food is about as much as 1 gram of pellet food, since pellet food is just dried food ground up and stuck together.
4% of this guy's weight is 0.7g. If I can work out how much 0.7g of wet food weighs when dry, that's probably how much pellet food he'd want, assuming the math works out for this species.

How do I tell if a worm isn't getting enough to eat? Will he come out and roam around looking for more?

They come out looking if they are hungry.

 

[ISpeakForTheSeas]

I remembered these guys are okay out of water for a bit, so I poured out all the water, very quickly weighed him in the cup (34g), refilled his cup, weighed an empty cup (16.5g), and got what should be about the right number. 17.5 grams of worm! 17,500mg.

As to food weight, I remembered the Avast Marine website talks about measurements of their dried food compared to frozen foods.

I could probably base something off of this. Or I could weigh a small portion of wet frozen food, let it dry completely out, and then weigh it again. I imagine 1 gram of dried fish food is about as much as 1 gram of pellet food, since pellet food is just dried food ground up and stuck together.
4% of this guy's weight is 0.7g. If I can work out how much 0.7g of wet food weighs when dry, that's probably how much pellet food he'd want, assuming the math works out for this species.

How do I tell if a worm isn't getting enough to eat? Will he come out and roam around looking for more?

Wow, I knew my estimate would be off by a bit, but that's a heavy worm!

Yeah, I'd assume that it would be roaming around if it needs more food.

 

[GARRIGA]

I’d be afraid to stick my hand in your tank lol

 

[Tired]

Oh, this isn't the tank you need to be concerned about. The other setup I have contains a gorilla crab with claws as thick as my finger, and one that's learned to come running out of the rockwork for food when someone leans over the tank. Bristleworms, at least, stay in the rockwork.

I'm gonna pop this guy back in. He's very neat. And, if nothing else, he should quickly handle anything that dies in here.