page_title: Australian lungfish
section_title: Description
hierarchical_section_title: Australian lungfish / Description
caption_attribution_description: Fig. 89. The Barramunda (Ceratodus) (From Queensland.)
context_page_description: The Australian lungfish, also known as the Queensland lungfish, Burnett salmon and barramunda, is a surviving member of the family Neoceratodontidae and order Ceratodontiformes. It is one of only six extant lungfish species in the world. Endemic to Australia, the Neoceratodontidae are an ancient family belonging to the class Sarcopterygii, or lobe-finned fishes.
  Fossil records of this group date back 380 million years, around the time when the higher vertebrate classes were beginning to evolve. Fossils of lungfish almost identical to this species have been uncovered in northern New South Wales, indicating that Neoceratodus has remained virtually unchanged for well over 100 million years, making it a living fossil and one of the oldest living vertebrate genera on the planet.
  It is one of six extant representatives of the ancient air-breathing Dipnoi that flourished during the Devonian period and is the outgroup to all other members of this lineage.
  The five other freshwater lungfish species, four in Africa and one in South America, are very different morphologically from N. forsteri.
context_section_description: Australian lungfish are olive-green to dull brown on the back, sides, tail, and fins, and pale yellow to orange on the underside. They have been described as having a reddish colouring on their sides which gets much brighter in the males during the breeding season. This colouration is the only distinguishing sexual characteristic of the lungfish. They have stout, elongated bodies and flattened heads with small eyes. The mouth is small and in a subterminal position. The lungfish can grow to a length of about 150 cm (4.9 ft), and a weight of 43 kg (95 lb). It is commonly found to be about 100 cm (3.3 ft) and 20 kg (44 lb) on average. Both sexes follow similar growth patterns, although the females grow to a slightly larger size. They are covered in slime when taken from the water.
  The skeleton of the lungfish is partly bone, and partly cartilage. The vertebrae are pure cartilage, while the ribs are hollow tubes filled with a cartilaginous substance. The body of the lungfish is covered with large, bony scales. Ten rows occur on each side, grading to small scales on the fins. The scales are each embedded in their own pockets, and overlap extensively, such that vulnerable areas of the body are covered by a thickness of at least four scales. Two unusually large and thick interlocking scales cover the back of the head where the bony skull is thin. Their cranial muscles (around the skull and jaw) follow similar patterns observed in other vertebrates, whereby the muscles tend to first develop from anterior to posterior, and from their region of origin toward insertion. They have powerful diphycercal tails that are long and paddle-shaped. The pectoral fins are large, fleshy, and flipper-like. The pelvic fins are also fleshy and flipper-like and situated well back on the body. The dorsal fin commences in the middle of the back and is confluent with the caudal and anal fins.
  The dentition of the lungfish is unusual: two incisors, restricted to the upper jaw, are flat, slightly bent, and denticulated on the hind margin. These are followed by dental plates on the upper and lower jaws.
  Juveniles have different body proportions from mature adults. The head is rounder, the fins are smaller, and the trunk is more slender. Also, the brain is relatively larger and fills more of the cranial cavity in juveniles compared to adults. The mouth is initially terminal, but shifts back as the fish grows. The dorsal fin typically reaches to the back of the head in young juveniles, and gradually moves caudally until it only extends to the mid-dorsal region in adults. They show a gradual change in body form as they develop, but no metamorphosis is externally detectable and no obvious point occurs at which they can be termed adult. As a juvenile, the lungfish is distinctly mottled with a base colour of gold or olive-brown. Patches of intense dark pigment will persist long after the mottling has disappeared. Young lungfish are capable of rapid colour change in response to light, but this ability is gradually lost as the pigment becomes denser.
  The lungfish is reputed to be sluggish and inactive, but it is capable of rapid escape movements with the use of its strong tail. It is usually quiet and unresponsive by day, becoming more active in the late afternoon and evening.
caption: Queensland lungfish
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