Convention wisdom and decades of aquarium literature says if you feed your fish white worms every day then they will almost certainly become fat; "whiteworms are a fatty food" is the claim. I don't doubt people have had problems with them, but I have not. Typically we are told to feed white worms bread soaked in milk and one has to wonder how natural of a diet this is - do worms really eat wonder bread and butterfat in the wild? Probably not, so, I tried feeding other things to my whiteworm cultures such as pumpernickel bagels and carrot shavings and spirulina and began feeding my fish only white worms to see what would happen.

So I fed white worms and I waited. I waited for all my fish to bloat up and die, but it never happened ater a decade. They were fine. If anything they were not as fat as usual adult killies, they never got that slighter-larger-than-wild-type build that older tank raised killies seem to get. Hmm...

"White worms have a high protein (75 percent) and lipid (15 percent) content with relatively low levels of ash (6 percent, Walsh 2012). White worms are a good source of n-3 long chain polyunsaturated fatty acids, though the DHA content may be limiting (Fig. 2). Worms provide a balanced supply of essential amino acids including tyrosine, tryptophan, arginine, histidine, cystine and methionine, as well as calcium, phosphorus, iron, carotene and vitamins A and B2 (Ivelva 1973)."

"The use of marine worms as a protein source in formulated fish feeds is not a new concept. Dragonfeeds, a subsidiary of UK-based Blue Marine Feeds Limited, combines the cultured polychaete Nereis virens with plant proteins to produce a feed with no fishmeal that has an amino acid profile similar to fishmeal. With a 70 percent protein and 2 percent lipid composition, the Dragonfeed product is marketed for finfish and shrimp aquaculture. Aquathrive, manufactured by Reed Mariculture/Reef Nutrition, combines fishmeal and oil with Terebellid polychaetes to produce a 46 percent protein, 11 percent lipid feed that is marketed mainly to aquarium hobbyists." (Walsh 2012)