Bloodworms junk food? Not so fast.

[neutrino]

I frequently stay out of it when the subject of bloodworms comes up, or I might make a comment saying I've found they have their place and in personal experience they seem to stimulate spawning in some SA species-- I'm posting this in the CA/SA forum mainly due to the following: I've been aware of this article by Lee Newman for some time (if you're not familiar with him, he's a curator at the Vancouver Aquarium and is well known in cichlid literature for spawning difficult species of Satanoperca, Retroculus, etc.). Here's a quote:

Satanoperca daemon

"More recently, I've been in contact with a researcher at Texas A&M University who has spent time in the field studying the feeding behavior, and diet, of wild S. daemon. In personal correspondence, he described how in approximately 300 fish ranging in size from very small juveniles to full-grown adults the most significant food item was Chironomid larvae - bloodworms. He therefore suggested that bloodworms make up a significant portion of the diet of captive S. daemon. Evidently, the gut content research explains the enthusiasm S. daemon show toward bloodworms despite the list of objectionable qualities cichlid keepers often report with them."

And in a recent discussion, he shared this paper:
https://www.ijzab.com/files/publish/3. IJZAB ID No. 372.pdf?fbclid=IwAR0e9ljLDY6EURtQJ5V-9CZGjKyZr4iEkNfzg4GeItXXMURSRa5scGuPgc4

 

[neutrino]

...As to being allergic, which some apparently are and no argument with that here, they don't bother me.

 

[Sinister-Kisses]

I bred extremely high quality bettas for 3 years. Any betta I own, then or now, eats a diet consisting of only frozen blood worms and brine shrimp, at a ratio of about 75% blood worms and 25% brine shrimp. It is literally the best diet for them, aside from live food. No pellets, no flakes, no freeze dried food of any kind.

So no, blood worms being "junk food" isn't valid as far as I'm concerned, I have have zero hesitation feeding them occasionally to my goldfish and various cichlids.

 

[FJB]

I believe strongly on a varied diet; I also do not believe in exclusively vegetarian, nor exclusively carnivorous fish. Granted, I do not keep ambush predator fish, so my argument does not apply as strongly to those.
Frozen bloodworms, frozen enriched brine shrimp, mysids, are part of my normal rotation for all my fish, and the rotation also includes insect-based and algae based flakes and pellets, as well as live earthworms, nori and some seeds. I would not feed exclusively bloodworms, or any other food for that matter.
If fed exclusively, I would consider bloodworms as an incomplete diet, but I would say the same for any other food.

 

[neutrino]

When I feed them it's typically a comparatively small %, though it's interesting to know they make up a significant fraction of certain species' wild diet. I posted this primarily because I see so many comments to the effect that bloodworms are a waste of time or they're like McDonalds, candy, or ice cream, with no nutritional value. Apparently incorrect.

So my take away isn't revolutionary, but similar to what I've done before and basically this:

The results of the present study correlates with the findings of (Mohseni et al., 2012), found that fish fingerlings fed chironomidae larvae and formulated feed had better growth performance...

 

[esoxlucius]

This info doesn't surprise me in the least.

The lowly bloodworm gets unnecessary bad press imo. When you think that the bloodworm is readily available in the wild to fish, then it's a no brainer to me that they should form part of your fishes diet in an aquarium.

Just think of the foods that are commonly fed as a matter of course, and yet fish are extremely unlikely to ever come across them in the wild! Terrestrial fruit and veg stick out, along with beef heart.

 

[RD.]

The only times that I have fed BW is when I used it to train fish raised on an exclusive diet of BW, to eat pellets. That, and a few difficult to convert wild fish. Worked like a charm, every time.

Years ago when speaking with a breeder in Thailand he told me that the vast
majority of flowerhorn raised in SE Asia are raised on an exclusive diet of BW. Not because the fish eat them in the wild (insert grin) but because they can collect them in ditches and other waterways, for free. And of course the juvenile fish gobble them up. They certainly contain protein/fat, but depending on the source can be void of many other nutritional elements. That, and with commercial frozen BW being made up of approx. 80% water content (a non nutrient), to have any serious impact on growth I would think that a fish would require a fair amount over the course of a day, once it gets gets past fingerling stage of life.

 

[RD.]

BTW - just wanted to add, most "basal diets" used in studies like this (this one appears to be based in India) typically use lower quality raw ingredients, such as grains, soy/wheat/corn etc. Whatever is cheap, and available. Most studies in NA mirror this as well. Rarely is a higher quality feed with higher quality raw ingredients used in commercial studies, and fish. Most researchers in this area are looking for ways to reduce feed costs, not increase them. What better than the larvae from midges that are abundant and widely distributed throughout India. No argument there.


The crude protein listed in the basal diet was only 32%, and the 55% shown for the BW, is simply not possible.

55% protein cannot be possible in frozen or fresh BW, and/or contain 05% moisture. Me thinks that these researchers funged up their number, or were feeding dried BW, not frozen as stated in the paper.



As an example......

A typical analysis of freeze dried bloodworms.

Guaranteed Analysis
Min. Crude Protein - 55%
Min. Crude Fat - 3%
Max. Crude Fiber - 5%
Max. Moisture - 5%

A typical analysis of frozen bloodworms. (from the same manufacturer as above)

Guaranteed Analysis
Min. Crude Protein - 6.3%
Min. Crude Fat - 0.8%
Max. Crude Fiber - 0.3%
Max. Moisture - 91.2%


Also, one could argue that when feeding a dry feed that is low in palatability due to higher inclusion rates of raw ingredients such as soy/wheat/corn, whatever, that clearly when fed that dry food exclusively, growth would not be as great as when one adds in a food that is very palatable to most fish, and that most fish will feed on until they reach satiation. The fact that they specifically mention that the pelleted feed decomposes into small particles in contact with water, kind of points to the overall quality of the feed.

 

[neutrino]

Good point about the potential quality of prepared dry food in the study, it crossed my mind when they mentioned crumbling particles, but for all I know they make their pellets in a toaster oven, so I didn't think too hard on it. As interesting to me as the lab study was the field research on S. daemon. The frozen vs freeze dried numbers are interesting and don't surprise me much-- I use only freeze dried.

I'm not making any point except that bloodworms aren't as useless as some think they are. In some of the Lee Newman Satanoperca articles he talks about including crustacean and plant components and using crushed pellets in making up his own gel food, obviously bloodworms are just one among several items. Only logical since small crustaceans, insect larva, and plant matter all seem to pretty consistently be part of the wild diet of Satanoperca and other eartheaters (not to mention a lot of other SA cichlids), at least one of which, Satanoperca acuticeps, is apparently as much a water column filter feeder as an "eartheater."

 

[jjohnwm]

I often wonder how blood worms came to be the target of all these accusations, when in actuality it seems that just about any frozen food would fall into the same category, i.e. mostly water with very little protein or any other nutrients when measured by either weight or volume. The same "problem" exists with frozen brine shrimp or any other frozen foods; in fact, the same holds true for live foods as well. Everything is mostly water. Drying or freeze-drying these food items produces those oh-so-marketable high values for proteins, etc.

I have often thought that the freezing process must result in the rupturing of cells, which then release much of their content into the surrounding water when they are thawed. Going by that "logic", it would seem that the best way to get the maximum nutrition out of frozen foods would be to feed them in the frozen state, but that doesn't seem workable. For small fish, a cube of frozen whatever dropped into the tank immediately begins to thaw and break up, so that the small pieces the individual fish actually ingest are already thawed and depleted of much of their internal goodness. For larger fish, I can't believe that ingesting a big frozen chunk of food...even though it contains everything it should...can possibly be healthy. Think of an ice-cream-induced "brain freeze" but on a much more massive scale.

So...I thaw the cubes I intend to feed to small fish; I use a fair bit of frozen blood worms, brine shrimp (adult and baby), plankton, etc. The cubes go into a glass of water and are allowed to sit until thawed and settled, the top 90% of the water is carefully poured off...it's a cloudy soup of internal juices, probably containing half or more of the original nutritional value of the food...and I often fill the glass up a second time and allow it to re-settle before once again decanting the excess water, likely removing even more nutrients. But once the cell walls have ruptured and the juices are released, they are lost to the fish and serve only to pollute my water, so why not get rid of them?

Why are the blood worms more targeted for vilification than other foods? Blood worms are midge larvae, and in life they are covered with a fairly hard chitinous layer that is largely non-nutritional...but so are brine shrimp and Daphnia and Mysis, and yet we don't hear them being vilified to the same extent. In all of these cases, the part of the animal that survives the freezing/thawing process more or less intact...and allows the thawed item to retain its shape and solidity...is the least nutritious part, i.e. the shell.

Back in the day, when I had time for such things, I often collected my own live foods from natural local sources, and developed my own methods and techniques for various food species. I used live mosquito larvae, bloodworms, tubifex worms and Daphnia regularly; each required its own technique to harvest efficiently, and all were messy and usually smelly affairs. Tubifex and bloodworms were absolutely the worst; another hit against bloodworms was the often-reported "fact"...don't know if it was actually true...that live bloodworms were capable of chewing their way out of a fish after being swallowed. Could they? Or was this just some of the rationalization that is so common? You know...I am told I "should" be conditioning my fish with live food, but these little red worm things are a PITA to actually collect...and I can't buy them like I can other live foods...but, hey, I hear they can be dangerous to my fish, so that's why I avoid them...yeah, that's it...

TLDR: I think blood worms get a bad rap, dating back many years. I don't think they are any worse, or better, than most other frozen or live foods. In order to make valid comparisons, you must compare apples to apples...i.e. live to live, frozen to frozen, freeze-dried to freeze-dried. No fudging the numbers by comparing a live item to a freeze-dried one.