...... from Ad Konings book; Back to Nature Guide to Malawi Cichlids 2nd. edition pg. 46:
"Malawi Bloat is believed to be caused by a flagellate (a unicellular animal, a protozoan). This flagellate occurs in the intestines of all Malawi cichlids but normally causes no harm since the fish's immune system can cope with it. However, in a stressful situation such a balance may disappear and the fish may lose its resistance against an outbreak of a flagellate "attack". This often leads to bloat."
Ad Konings view is one that is shared amongst most scientists & researchers that work in the field of aquatic disease.
Bloat is nothing more than a "symptom", to which there could potentially be scores of underlying causes. The shipping alone could have been enough to push some of these fish over the edge.
Most of the pathogens found in aquaria can co-exist in harmony with fish, it's typically only under stressful conditions, when a fishes immune system becomes compromised when these protozoans gain the upper hand and become pathogenic. If those flagellates (such as hexamita/spironucleus) enter the abdominal cavity, then travel via the blood to organs - typically you have a very short window of opportunuity before the organs shut down, and the fish "bloats" up.
Clinical signs of fishes infected by diplomonad flagellates vary from no clinical signs (Mo et al., 1990) to severe symptoms (Kent et al., 1992). Infected salmonids and aquarium fishes may show clinical signs of anorexia, anemia, emaciation, lethargy, hyperpigmentation, fecal pseudocasts, enteritis with excess mucus and yellow watery or jelly-like contents or swollen abdomen (Ferguson and Moccia, 1980; Kent et al., 1992; McElwain, 1968; Mo et al., 1990;
The very fact that Honda got some of these exact same fish, from the same breeder, and has been feeding NLS with no absolutely issues, clearly proves that your fish did not become ill due to their diet.
