How do the body shapes of African and South American lungfish differ from the Australian lungfish?

The body shapes of African and South American lungfish differ significantly from the Australian lungfish. While the Australian lungfish is more compactly built and resembles ancient fossil forms, the African and South American species possess a slim, eel-like appearance.1

Key physical differences include:

• Build and Scales: The Australian lungfish has a compact body covered in large overlapping scales, whereas the African and South American varieties are much slimmer.1
• Fins: The pectoral and pelvic fins of the Australian lungfish are notably broader. In contrast, African and South American lungfish have long, stringy, and highly mobile fins used for sensing their environment.1
• Respiratory Anatomy: The African and South American lungfishes possess paired lung sacs, while the Australian lungfish has only one, as its left lung sac has atrophied.1