Can anyone I.D this worm please?

[EmJay]

Just found this worm in the substrate of my shrimp tank. It is a yellowy colour and approx 40mm long. Does anyone know what it is please?

 

[Slaphppy7]

Detritus worm, usually the result of overfeeding

 

[Essjay]

I had no idea detritus worms grew that big I always thought they were little white things not 4 cm/1.6 inches long.

 

[WhistlingBadger]

Yeah, that's a big one, but I do think it's a detritus worm. Generally harmless.

 

[Back in the fold]

That thing ain't normal. Kill it !

 

[Guyb93]

I know not everyone has greedy fish but my fish would eat that
Iv has pest snails evicted to the filter because my fish won’t allow any population of snails in the tank

I literally hid an earth worm in the sand hoping the turtle would dig it out eventually.... nope the fish just dig down like time team and eat
It’s annoying really as you have to target feed the slower things

 

[Back in the fold]

@Guyb93 I have Aplocheilus lineatus Golden Wonder Killifish that will not let snails live at all. They eat them shells and all. They eat them as they hatch and they eat the egg sacs. I have some pond snails that I'm keeping separate just to have them. Nothing stops hungry fish.

 

[Colin_T]

It's not a detritus worm, way too big and wrong colour for that.

It's just an aquatic worm and harmless. Put it back in the substrate.

 

[Guyb93]

@Guyb93 I have Aplocheilus lineatus Golden Wonder Killifish that will not let snails live at all. They eat them shells and all. They eat them as they hatch and they eat the egg sacs. I have some pond snails that I'm keeping separate just to have them. Nothing stops hungry fish.

If it lives it’s food ahahah I don’t know weather tetra change the way they eat when living with cichlids but even they will rip apart a 10cm earth worm no issue . I always get amazed when people find mystery worms n stuff . I have fish vanish without even a fin to be seen there is just no way in a thousand scenarios that a worm could survive the thunder dome lol

 

[Slaphppy7]

It's not a detritus worm, way too big and wrong colour for that.

It's just an aquatic worm and harmless. Put it back in the substrate.

Grow to "about an inch", according to the below...the one the OP has is just a well-fed grandaddy

Detritus Worms in Aquarium – Are These Harmful to Fish (Complete Guide) - Fish Parenting - Ultimate Fishkeeping Guide

You might have noticed several linear movements in the fish tank and wondered if it was anything harmful. Well, not to worry, as these may...

www.fishparenting.com

Detritus Worms: Causes & How To Get Rid Of them

Many aquarists don’t know what to do when they see detritus worms in their aquarium. Read this guide to find out what your options are.

www.aquariumsource.com