Marbled Lungfish

The marbled lungfish (Protopterus aethiopicus) is a large African freshwater fish that breathes air with lungs and can survive the drying of its habitat inside a mud cocoon. Lungfishes are the closest living relatives of land vertebrates.

🧬 Field Guide Specimen: Open Marbled Lungfish in the CRV Science Field Guide to log the specimen, see its place among the Vertebrates lineages in the Cladogram Explorer, and test your recall in the Red List conservation game.

When the swamp dries out, the lungfish burrows into mud and secretes a mucus cocoon, then enters aestivation, a dormant state in which its metabolism drops dramatically. It converts its waste to urea, which is less toxic than ammonia and can be stored. It can survive for months, and in some lungfish for years, until rain returns.

Genome studies in 2021 showed that lungfishes are more closely related to tetrapods (amphibians, reptiles, birds and mammals) than coelacanths are. The lungfish genome is also enormous: African lungfishes have some of the largest genomes of any animal, mostly made up of repetitive DNA.

The eel-like fish has thread-like paired fins and builds a nest, with the male guarding the young. It is eaten locally and is sometimes a pest to rice farmers.

• Coelacanth — another lobe-finned fish
• Evolution — the transition to land