Definition

1. Noun:
   • An unpaired median fin located on the back of a fish or some other aquatic vertebrates, which aids in maintaining stability and balance during swimming.

Usage

• The word "dorsal fin" is a compound noun used specifically in zoology and marine biology to describe a distinct anatomical feature.
• It is typically used with the definite article "the" when referring to the specific fin on a particular animal (e.g., of a shark).
• It can be modified by adjectives describing its size, shape, or condition (e.g., a dorsal fin, a dorsal fin).

Examples

• Noun:
  • The shark's dorsal fin cut through the water's surface.
  • Scientists can identify dolphin species by the shape and size of their dorsal fin.
  • The injury to the whale's dorsal fin did not seem to affect its swimming.

Advanced Usage

• "Erect the dorsal fin": A behavioral term where a fish raises its dorsal fin, often as a display of aggression or alertness.
  • The betta fish will erect its dorsal fin when it feels threatened.

Variants and Related Words

• Fin: (noun) A general term for a thin flat part on the body of a fish, used for steering, balancing, or propulsion.
• Pectoral fin: (noun) Either of a pair of fins located on each side, usually behind the gills.
• Caudal fin: (noun) The tail fin, used for propulsion.
• Anal fin: (noun) An unpaired fin located on the ventral (bottom) side near the tail, aiding in stability.

Synonyms

• Back fin: A less technical synonym.
• Spine fin: Sometimes used, particularly when the fin has hard, spiny rays.

Related Phrases

• Finning: (noun) The practice of removing a shark's fins (including the dorsal fin) and discarding the body at sea.
  • The international trade in shark fins has led to bans on finning in many waters.

Noun

1. unpaired median fin on the backs of fishes and some other aquatic vertebrates that help to maintain balance