Long-Lived, Demanding, and Endlessly Fascinating

Lungfish are among the longest-lived animals kept in captivity. The famous Australian lungfish "Granddad" at the Shedd Aquarium in Chicago was an institution resident for over 80 years before dying in 2017 — and he was already an adult when acquired. African lungfish in managed care have also been known to survive for several decades. Keeping these animals well requires understanding their unique biology and respecting the considerable commitment they represent.

Species Kept in Captivity

All six living lungfish species have been kept in zoological and aquarium settings, but the most commonly encountered in institutions are:

  • Protopterus annectens (West African lungfish) — The most widely available species in the trade, relatively hardy, and manageable in size.
  • Protopterus aethiopicus (Marbled lungfish) — Impressive but very large; requires substantial tank space and can be aggressive.
  • Neoceratodus forsteri (Australian lungfish) — Rarely seen outside of Australia; strictly regulated and not available in the private trade.
  • Lepidosiren paradoxa (South American lungfish) — Occasionally kept; less commonly encountered than African species.

Basic Care Requirements

Tank Size

Lungfish are not small animals. Protopterus annectens reaches 70–100 cm; P. aethiopicus can exceed 2 meters. Even smaller species require a tank of at least 400–600 liters for a single adult, with larger setups strongly preferred. Dim lighting and ample hiding places reduce stress.

Water Parameters

  • Temperature: 24–28°C (75–82°F) for African and South American species
  • pH: 6.5–7.5 (slightly acidic to neutral)
  • Filtration: Moderate — lungfish tolerate lower oxygen levels but still benefit from good biological filtration to handle their significant waste output
  • Substrate: Soft sand or fine gravel; lungfish dig and may injure themselves on rough substrate

Air Access

This is non-negotiable: lungfish must be able to reach the water surface to breathe air. A tank cover is essential to prevent escape, but it must allow easy surface access. African and South American species will drown if unable to breathe air — a critical point for any keeper to understand before acquiring one.

Feeding in Captivity

Captive lungfish generally accept a wide range of foods. Suitable dietary items include:

  • Earthworms (a staple food for many keepers)
  • Freshwater mussels and snails (in shell, to promote natural tooth plate use)
  • Prawns and shrimp
  • Pieces of fish fillet
  • Commercial carnivore pellets (some individuals accept these readily)

Feeding frequency depends on temperature and individual metabolism — typically every 3–7 days for adults. Overfeeding is a common mistake; lungfish have slow metabolisms and do not need to eat as frequently as most fish.

Behavioral Considerations

Lungfish in captivity display several notable behaviors that keepers should be prepared for:

  • Aggression: Most lungfish are territorial and should generally be kept alone or with similarly sized, robust tankmates — if at all. They can inflict serious bites.
  • Burrowing: Given the opportunity, African lungfish will burrow into soft substrate. Providing suitable conditions for this natural behavior reduces stress.
  • Induced aestivation: In some institutional settings, African lungfish have been induced into aestivation for short periods — useful for temporary transport or veterinary procedures. This requires careful management.
  • Escape attempts: Lungfish are surprisingly mobile and will escape from open tanks. Secure lids are essential.

Institutions and Notable Specimens

Several aquariums and natural history institutions have maintained lungfish as long-term residents and made meaningful contributions to understanding their husbandry:

  • Shedd Aquarium, Chicago — Home of "Granddad," likely the oldest fish in captivity when he died in 2017.
  • Queensland Museum and Freshwater Research centres — Have maintained Neoceratodus forsteri and contributed significantly to research on Australian lungfish reproduction and physiology.
  • Various European zoos and aquariums — African species are well-represented in European collections, and inter-institutional cooperation has improved husbandry knowledge considerably.

Final Thoughts for Prospective Keepers

Lungfish are not beginner animals. They are long-lived (potentially outlasting their owners), large, and require specific conditions. For those prepared to meet their needs — and willing to make a decades-long commitment — they are among the most rewarding and scientifically interesting animals one can keep. Before acquiring any lungfish, research your local regulations: several species are subject to trade restrictions, and responsible acquisition from reputable sources is essential.