cow shark

Thân thiện

A cow shark swims slowly through a sunlit coral reef.

Definition

Noun: 1. A large, primitive shark species widely distributed in warm seas: This term refers to any shark belonging to the family Hexanchidae, characterized by having six or seven gill slits (unlike most sharks, which have five), a single dorsal fin, and a primitive body structure.

Usage Examples

• Noun:
  • The bluntnose sixgill shark is a type of cow shark found in deep waters.
  • Marine biologists were excited to spot a rare cow shark during the deep-sea expedition.
  • Cow sharks are considered living fossils due to their ancient lineage.

Advanced Usage

• In a taxonomic context: The term "cow shark" is often used in scientific and marine biological texts to refer to the family Hexanchidae.
  • The fossil record suggests cow sharks have changed very little over millions of years.

Variants and Related Words

• Hexanchid (n): The scientific, adjectival form relating to the cow shark family (Hexanchidae).
  • The hexanchid morphology is distinct from other shark orders.
• Sixgill shark (n), Sevengill shark (n): Common names for specific species within the cow shark family, referring to the number of gill slits.
  • The bigeyed sixgill shark is a deep-water cow shark.

Synonyms

• Frilled shark (Note: While also primitive, the frilled shark () belongs to a different family. It is sometimes colloquially grouped with primitive sharks but is not a true cow shark.)
• Primitive shark (n): A broader descriptive term that can include cow sharks.

Related Phrases/Compounds

• Cow shark family (n): Refers to the taxonomic family Hexanchidae.
  • The cow shark family includes some of the most ancient shark species.

Học thuật

Noun

1. large primitive shark widely distributed in warm seas

Từ đồng nghĩa

• six-gilled shark
• Hexanchus griseus