Coco worm dropped both fans

ACIAMPA · Mar 30, 2025

I have a beautiful red and gold coco worm, has been doing great for 3+ months. One night I noticed one side of the tube had a small chip and one of its fans was on the sand. I just figured one of my tangs smashed into it. It would extend but not fully for 2 days then it dropped the other fan as well. Would trauma cause the worm to drop both fans like that even if it wasn’t cut? I can still see the worms head.

ISpeakForTheSeas · Mar 30, 2025

ACIAMPA said:
I have a beautiful red and gold coco worm, has been doing great for 3+ months. One night I noticed one side of the tube had a small chip and one of its fans was on the sand. I just figured one of my tangs smashed into it. It would extend but not fully for 2 days then it dropped the other fan as well. Would trauma cause the worm to drop both fans like that even if it wasn’t cut? I can still see the worms head.

Yes, trauma, starvation, predation, etc. can cause these to drop their branchial crowns (the feather dusters of the worms). Sometimes they drop them for no apparent reason. With enough time under good conditions, though, they can regrow the crowns. If you haven't been feeding it, now may be a good time to start, as they do use the crowns to help with feeding and breathing.

ISpeakForTheSeas said:
For feeding, generally feather dusters want phyto - I haven't looked into the smaller species specifically, but I'd guess they feed on phyto/bacteria like the larger ones (though I may be wrong); I'd recommend specifically Isochrysis galbana [T-Iso], Chaetoceros sp. [and/or Thalassiosira sp.], and Tetraselmis sp. or a blend involving multiple of these. Skeletonema species would be another good choice.

Isochrysis galbana/T-iso and Chaetoceros muelleri have been used in the aquaculture of larger feather duster species, so those would be my first thought to feed.

56longroof · Mar 30, 2025

There are a few reasons they do this. Trama is one. Are your parameters ok? Do you feed it often? If it stays in good health it will regrow new "feathers".

ACIAMPA · Mar 30, 2025

@56longroof @ISpeakForTheSeas yes I feed indirectly 2-3 times per week, everything otherwise normal in the tank.

56longroof · Mar 30, 2025

ISpeakForTheSeas said:
Yes, trauma, starvation, predation, etc. can cause these to drop their branchial crowns (the feather dusters of the worms). Sometimes they drop them for no apparent reason. With enough time under good conditions, though, they can regrow the crowns. If you haven't been feeding it, now may be a good time to start, as they do use the crowns to help with feeding and breathing.

Can they still feed with the branchial crown missing?