Lungfish

? Lungfishes
Queensland Lungfish
Scientific classification
Kingdom: Animalia Phylum: Chordata Subphylum: Vertebrata Class: Sarcopterygii Subclass: Dipnoi Müller, 1844
Orders
See text.

Lungfishes are sarcopterygian fish that can breathe air (and in some species are obligate air-breathers), and have limb-like appendages instead of fins. There are six living species known; four in Africa, and one each in South America and Australia. Most of their skeleton is made out of cartilage, and electro receptors can be seen as tiny holes under their jaw. The modern lungfishes have a number of larval features, which suggest paedomorphosis. They have probably the largest genome among the vertebrates.

They all have an elongate body, four limbs, and a single rear fin.

Taxonomy

Taxonomy of lungfishes presents some difficulty because of their resemblances to both fish and land-dwelling vertebrates, and have been classified in a variety of ways, ranging from class Dipnoi, to infraclass Dipnomorpha, to order Dipteriformes. However, there is general agreement that there are two main subcategories, here given as orders:

• Ceratodontiformes: characterized by having broad flipper-like fins and an unpaired lung.
  • Family Ceratodontidae,
    • Genus Neoceratodus
      • Neoceratodus forsteri - Queensland Lungfish
• Lepidosireniformes: characterized by having thread-like fins and paired lungs.
  • Family Lepidosirenidae
    • Genus Lepidosiren
      • Lepidosiren paradoxa - South American Lungfish
  • Family Protopteridae
    • Genus Protopterus
      • Protopterus aethiopicus - Marbled Lungfish
      • Protopterus amphibius - East African Lungfish
      • Protopterus annectens - African Lungfish
      • Protopterus dolloi - Slender Lungfish