Definition

Noun 1. A type of fish that can breathe air: A lungfish is a freshwater fish belonging to a primitive group. Its most distinctive feature is the possession of one or two lungs, which allow it to breathe air directly. This adaptation enables it to survive in stagnant or oxygen-poor water and to endure periods of drought. 2. A fish with both gills and lungs: It is an elongated fish with fleshy, paired fins that resemble limbs. It retains functional gills but relies primarily on its lung(s) for respiration.

Usage Examples

• Noun:
  • The lungfish is often studied by biologists because of its unique evolutionary position.
  • During the dry season, the lungfish burrows into the mud and secretes a mucus cocoon.
  • Fossils show that the lungfish has existed for hundreds of millions of years.

Advanced Usage

• Evolutionary significance: The term "lungfish" is frequently used in scientific contexts to discuss vertebrate evolution, as it represents a transitional form between aquatic fish and terrestrial vertebrates.
  • The anatomy of the lungfish provides clues about how fins may have evolved into limbs.

Variants and Related Words

• Dipnoi: (Scientific noun) The subclass to which all lungfish belong.
• Aestivation: (Noun) The state of dormancy or torpor entered by some animals, including lungfish, to survive dry, hot periods.

Synonyms

• Air-breathing fish: A descriptive synonym highlighting its primary physiological adaptation.
• Sarcopterygian: (Scientific noun) A member of the class Sarcopterygii, the lobe-finned fishes, which includes lungfish and coelacanths.

Related Phrases/Concepts

• To aestivate: (Verb) To enter a state of summer dormancy. This is a key survival behavior associated with lungfish.
  • The African lungfish can aestivate in its mud cocoon for several years.
• Bimodal respiration: (Noun) The biological capacity to breathe using two different methods (e.g., gills and lungs). This is a defining characteristic of the lungfish.

Noun

1. air-breathing fish having an elongated body and fleshy paired fins; certain species construct mucus-lined mud coverings in which to survive drought