Causative agent: Nutritional deficiency (vitamins A, C, and HUFA); activated carbon leaching; stray electrical voltage from faulty equipment; poor water quality
Head and Lateral Line Erosion (HLLE) is a chronic and progressive condition most commonly seen in tangs, surgeonfish, and marine angelfish in Australian reef aquariums, although cichlids in freshwater setups can also be affected. Unlike infectious diseases, HLLE is caused by environmental and nutritional factors — primarily deficiencies in vitamins A and C, the use of activated carbon in filtration (which may strip essential trace elements from the water), and stray voltage from faulty equipment entering the tank. The condition manifests as progressive pitting and erosion of the tissue on the head and along the lateral line — the sensory canal running down the fish's body — giving affected fish a pockmarked, faded appearance. The encouraging news is that HLLE can often be reversed: removing activated carbon, eliminating stray voltage, and significantly upgrading the diet to include fresh nori, vitamin-soaked foods, and high-HUFA foods can lead to dramatic improvement over several months. Australian reef keepers should provide tangs with daily nori as a dietary staple.
Symptoms
- •Pitting and erosion of tissue on the head and along the lateral line
- •colour fading around the pits
- •disfigurement of facial features
- •no open wounds in early stages
Treatment
- •Upgrade diet with vitamin-enriched foods, nori, and fresh vegetables
- •remove activated carbon from filter
- •check all equipment for stray voltage
- •improve water quality
- •Seachem Entice as supplement
Australian Medications
- •Vitamin supplements and enriched food available at Australian aquarium stores
- •Seachem Entice from specialty reef stores
Commonly Affected Fish
- •Marine tangs, surgeonfish, and marine angelfish most commonly affected
- •also freshwater cichlids
Important Notes
Distinct from Hexamita HITH — different cause and treatment. Condition CAN be reversed with dietary and environmental improvements.