Definition

Noun A microscopic, parasitic flagellate protozoan (Ichthyobodo necator, formerly Costia necatrix) that is the causative agent of costiasis, a frequently fatal skin and gill disease in freshwater fish.

Usage

The term "costia necatrix" is used specifically in veterinary science, aquaculture, and ichthyopathology to identify the parasite responsible for the disease. * The outbreak was confirmed to be caused by costia necatrix. * Microscopic examination revealed a heavy infestation of costia necatrix on the gills.

Advanced Usage

• The name is often italicized in scientific writing, as it is a former genus and species name (). Its current accepted taxonomic name is .
• It is typically used attributively to describe the associated disease or infestation.
  • Costia necatrix infestation can lead to rapid mortality in fry.
  • The primary symptom of costia necatrix infection is a bluish-white skin film.

Variants and Related Words

• Costiasis (n): The disease caused by , characterized by excess mucus production, skin irritation, and gill damage.
• Ichthyobodo necator (n): The current scientific name for the parasite.
• Flagellate (n): A type of protozoan that moves using one or more whip-like flagella.

Synonyms

• Ichthyobodo (when referring to the genus)
• Fish parasite (general term, less specific)

Related Phrases

• To be infected with costia necatrix: To have the parasite present on the body.
• An outbreak of costia necatrix: A sudden occurrence of the parasitic disease in a fish population.

Noun

1. a flagellate that is the cause of the frequently fatal fish disease costiasis