Flagtail

Flagtail refers to several different types of fish, usually characterized by distinctive, often colorful markings on their caudal (tail) fin. The name "flagtail" is generally applied due to the fin resembling a flag in appearance, often being elongated or exhibiting contrasting colors compared to the rest of the body. The term can be ambiguous, and the specific species being referenced requires context. Some common usages include:

• Kuhlia Species: The most common usage of "flagtail" refers to fish belonging to the genus Kuhlia, particularly Kuhlia sandvicensis (Hawaiian flagtail) and related species. These are perciform fish found in tropical and subtropical waters, both freshwater and brackish. They are typically silver-colored with a black and white striped pattern on the caudal fin. They are popular aquarium fish.

• Other Fish with Similar Tail Markings: The term "flagtail" can also be applied more generally to other fish species that possess similar flag-like markings on their tails, even if they are not closely related to Kuhlia. This is purely based on visual similarity and may be used in local or regional contexts. The specific species implied by "flagtail" outside of Kuhlia requires careful identification based on location and description.

• Potential for Misidentification: Due to the descriptive nature of the name, it's important to note that "flagtail" can be a source of confusion. Proper identification requires careful examination of other characteristics besides the tail fin, such as body shape, fin arrangement, and scale patterns. Always verify the exact species being discussed to avoid ambiguity.