Measuring at 1-3 inches in length, Larval Contereobestiolla were tiny creatures living in still freshwater. They remained as larvae until accidentally ingested by a fish host, whereupon they attached to the gut lining and pupated, hatching as mature arthropods to roam the gut freely. Adults lived on food swallowed by the host, multiplying and growing until they infested the entire gastrointestinal tract, sometimes causing great discomfort.