Black worms question

gwand · Oct 4, 2024

I can purchase live black worms to feed my fish but do not know anything about them as a food source. Anyone feed their fish black worms? How do they compare to brine shrimp or daphnia nutritionally? Can small fish eat them? Thanks.

Colin_T · Oct 4, 2024

They are cleaner than tubifex worms but can still be bad. If any of the worms are grey or white, they are dead and rotten. Healthy worms will be black. They can be fed to fish that are 1.5-2 inches+ long. Nutritionally, they are probably similar to Daphnia and brineshrimp ad ok to use as part of a varied diet. The main concern with them is how clean they are. Their water should be clear and not smell and no grey or white worms.

TwoTankAmin · Oct 4, 2024

Since Colin answered your size Qs and keeping them clean and live parts. I will add the following:

Live black worms are also a favored food by many people who breed their fish. Here is a decent article on both how to breed them or how to keep them if you buy them from a local store. They do take some work. The store part is near the bottom of the article.
www.selectaquatics.com/ft_13 Blackworm Culturing.htm

A few years ago the NEC, at their annual weekend event, they featured a breeders round table after the banquet. Rosario LaCorte (90 years old at the time), Eric Bodrock, Bill Cole, Regina Spotti are the names I remember on the dais but there were a couple more. Attendees were invited to submit questions. One of the questions which made it to be asked was, "What is your favorite food for conditioning your fish to spawn?"

I found two things interesting in the answers. The most common one was Black worms followed by blood worms. However, Rosario's answer surprised me he most. It was tubifex. He recounted how the they would collect them in canals and roadside ditches and what they had to do to make the safe to feed to the fish. But when he began his life long fish keeping, it was likely before I was born and I am in my mid 70s. There were not a lot food options back then.
https://moaph.org/article-archives/the-passing-of-a-legend-rosario-la-corte-1929-2024/

In the mid-1950s, Rosario became one of the few to spawn the fabled Neon Tetra (Paracheirodon innesi)...............
And, the spawning of the Neon Tetra led to many other notable spawnings of all kinds of fish. Many of those spawnings were the first of their kind in America, if not the world.

Live foods are some of the best ones we can feed to many of our fish. However, time and space constraints made me forgo live. I hatched BBS a few times and messed with red wiggler worms or few months. The worms worked well but were a PITA to keep. So I favor Repashy gel mixes and frozen foods.

fishorama · Oct 5, 2024

That was a great tribute to Rosario! I have to disagree with using tubifex is any form. Back in his early days they may have been safer than I've thought of them since early 80s. I sometimes buy live blackworms as a treat or breeding stimulus. But I've had issues from feeding even freeze dried tubifex. I'm not sure that all the issues were from tubifex, but never again in any form!

I have heard of fish leeches on blackworms but I have yet to see them. My worst issue is my husband doesn't want to see them in the fridge & I forget they're in there. When I'm on good bw husbandry, I rinse them in dechlorinated or tank water every couple days. I even had a colony of bws survive in my so called "riverish tank" for more than a few years. If I uprooted plants for my plant club, I needed to rinse them off or warn people they may be there. Some were happy to get them; others not so much.

When I had young discus, I bred white worms & red wigglers in my basement. I fed live & freeze dried blackworms sometimes & almost any food you can think of except daphnia. None of any my fish ever loved them, they'd a few & quit. Poor quality? Or spoiled for choices?

TwoTankAmin · Oct 5, 2024

I used to get frozen tubifex from Jehmco. Most of my fish liked them except for the Altum angels. I never had disease issues feeding them. But, I use about a dozen or more different foods so I stopped using the Tubifex.

Rosario also explained how they made them safe to feed. Given his reputation in the hobby I doubt they had many problems with this food. And like I wrote, there were not a lot of available alternatives when you go back that many decades. Bear in mind he was born in 1929. He was almost 20 when I was born in 1948.

Today we can get frozen foods that are pretty high quality and also disease free.

Now here we are in the 2000s and my biggest trick for conditioning my plecos to spawn is Repashy Spawn & Grow. I use lots of frozen as well and these foods are pretty much safe. the technology to get them that way and to make them even more nutritious wasn't even a dream when Rosario got his start and for decades afterwards.

Common sense tells me if the tubifex Rosario and other used were unsafe and killing fish he would have never succeeded in breeding anything let alone becoming an internationally known and respected expert.

Today not only are there live black worms but also:
https://kensfish.com/products/kens-premium-bloodworm-sticks
https://kensfish.com/products/kens-premium-blackworm-flake
https://www.amazon.com/Freeze-Dried-Blackworms-Preservatives-Alternative/dp/B0CF76HG5M?tag=ff0d01-20

There are also tubifex flakes and tubifex freeze dried. If these foods were dangerous for fish there would be information regarding this all over the net. Companies would lose their reps for harming fish with their food. And keeping live black worms safe to feed doesn't seem to be any less important than doing the same for tubifex?

GaryE · Oct 5, 2024

I have only been able to get blackworms a couple of times. To stimulate breeding, they are fantastic. That tells me they are nutritional. I evaluate all foods on how they affect fish egg production, mainly with my killies where it's easy to observe. If you don't want your fish to breed, I'd avoid them.

Daphnia are easy to raise outdoors, but I see no major effect on breeding from them. That has been a surprise to me.

I've never had enough live bloodworms to have an opinion.

Mosquito larvae have similar effects to blackworms here, except if you overfeed, you get fed on.

I hatch artemia daily, but I have small fish.

Colin_T · Oct 5, 2024

GaryE said:
I've never had enough live bloodworms to have an opinion.

You don't want to use live bloodworms (Chironomid midge larvae) because they can damage the fish's stomach if the fish swallows them whole. If the fish chews them up first it's not an issue but fish that swallow their food can die from swallowing live ones.

GaryE · Oct 5, 2024

I wonder if Australian bloodworms are the same species as Canadian ones? That's a whole other can of worms - the ones I find here are about 1/4 to 5/8 inch with no visible head structure.

It may be that we're calling wild collected bloodworms could be different beasts.

I notice we have midges here that bite hard, while 1000 k west, they weren't a biting species. I think the larvae looked the same to the eye.

fishorama · Oct 5, 2024

Many people are allergic to blood worms. 1 of my fav MA lfs didn't sell them in any form, the owner was very allergic. I'm slightly sensitive to them. I can tell if I've fed them within a day or 2 when I do a water change. I just get itchy as far as my arms were in the tank but it's not a big deal if I wash off with soap after tank care. Another reason to feed them as treats not part of a regular diet.

Like mosquito larvae, I won't feed live critters that can become people biters, eek! I'm also not a fan of freeze-dried worms. They take a lot of soaking & still might not sink for my midwater & bottom feeds.