Diagram showing steps in the life cycle of Huffmanela huffmani Moravec, 1987 (not to scale).

• A – adults lay eggs in definitive host; at least 7.5 months must pass between ingestion of viable larva and the appearance of fertilised eggs in the host swim bladder, but eggs do not become fully larvated and infective to amphipods until 11.5 months post infection (p.i.): 1 – centrarchid definitive host; 2 – photomicrograph of swim bladder tissue showing eggs in various stages of development;
• B – release of eggs from definitive host: 3 – definitive host dies and decomposes to release eggs; 4 – definitive host is consumed by piscivorous fish and viable eggs with sufficiently developed shells pass out in faeces;
• C – eggs free in sediments: 5a – young eggs (<10 months p.i.) with inadequately developed shells will not survive in environment or passage through piscivore gastrointestinal (GI) tract; 5b – unlarvated eggs old enough to have fully developed egg shells (>10 months p.i.) can survive in environment and through GI tract of piscivore, but are uninfective to amphipods until they become fully larvated while in sediments; 5c – fully larvated eggs (≥11.5 months p.i.) are immediately infective to amphipods and are still infective to amphipods after 36+ months in sediments;
• D – fully larvated eggs ingested by amphipod: 6 – larvae hatch and migrate to hemocoel where they must remain for at least 5 days p.i. before being infective to definitive host; 7 – larva in hemocoel of amphipod and infective to centrarchid. Life cycle can be completed in a theoretical minimum of 12 months, but can probably take longer than 36 months.