Gill Injuries in Pond Fish

The gills of pond fish are what allow them to filter oxygen out of the water and respire. Injuries to the gills of pond fish have a variety of causes including toxic compounds in the water, parasites, bacterial infections and fungal infections. Overstocking ponds and poor filtration makes pond fish somewhat more susceptible to gill injuries than other fish.

  1. Toxic Compounds

    • Chlorine and chloramines are compounds that are toxic to fish. They burn the gill tissue, rendering them ineffective. Fish can suffocate if the toxic compounds burn enough gill tissue.

    Parasites

    • Parasitic infections harm the gills of pond fish by clogging the gill tissues and preventing the proper exchange of oxygen and carbon dioxide. Some parasites can permanently damage gill tissue by causing wounds that allow the gills to become infected with bacteria or fungi, ultimately killing the fish if left untreated.

    Parasite Diagnosis

    • Parasitic infections are identified through a procedure known as scraping. Simple cotton-tipped applicators are used to collect a sample of the mucous and transfer it to a microscopic slide for examination.

    Disease

    • Some fish diseases can cause gill injury such as bacterial gill disease. Analyzing gill mucous also identifies diseases such as these.

    Hyperplasia

    • Hyperplasia refers to the formation of excess epithelial cells, in response to toxins in the water, parasite infection or bacterial infections. Gills are rendered less efficient due to the increased mucous and epithelial cells present.