All Diseases

Black Gill Disease

Black gill disease is one of the diseases that can infect vannamei shrimp on farms, especially those with poor environmental conditions. This disease, which can cause respiratory issues in shrimp and eventually lead to death, has been reported to occur in several countries, including Indonesia, Malaysia, and Taiwan.

Indication of Disease

Name

Black gill disease

Clinical signs

In the early stages, the gills will turn opaque white and then become yellow or brownish. In the acute infection stage, the gills will turn brown or black, then shrink and be damaged.

Method of diagnosis

Observing the symptoms, histopathology tests, microbiology tests, PCR, and Scanning Electron Microscope (SEM) analysis in the laboratory.

Pathogen

Name

Microorganisms named Fusarium and Aspergillus flavus (case example in India). Chemical factors include toxic compounds (nitrite, ammonia, acid, potassium permanganate, copper, cadmium, ozone, etc.).

Pathogen type

Fungus and chemicals

Synonyms

No information

Characteristics

Aspergillus flavus isolated from infected fish gills has a yellowish green color, a cotton-like texture, a granular shape, flat margins and elevations, with hyphae that has septates, as well as hyaline pigmentation and long conidiophores.

Pathogen Effect

Toxicity

It may cause respiratory problems in shrimp and even death.

Predispositional factors

Poor water quality, low DO concentration, pollution, and stocking density that are insufficient to the pond capacity.

Transmission

This pathogen can infect one shrimp with another directly or through a vector, such as ingestion, injection, physical contact, or air.

Epidemiology

Reported to occur in Indonesia, Malaysia, and Taiwan.

Inang atau vektor

No data

Dosis infeksi

No data

Incubation period

The incubation period has not been found, although early indications include pale white or opaque gills that turn brownish yellow and finally black.

Stability and Viability

Susceptibility to drugs

No information

Susceptibility to disinfectants/probiotics

No information

Physical inactivation

No information

Handling and Prevention

Early warning

If the pond bottom is not properly managed and the shrimp gills turn pale white, there is an indication that the shrimp are in the early stages of black gill infection.

Prevention

Preventive measures that can be taken include maintaining water quality conditions in the pond, controlling the pond bottom conditions, and preventing overfeeding. When the water quality deteriorates, change the water and add aeration. Pond preparation before starting a new cycle is also important, such as drying the pond bottom before stocking the fry. Drying must be done for two weeks as an attempt to kill disease-causing organisms such as fungus, bacteria, and viruses. In addition, the remaining organic substance will be oxidized until it is non-toxic. The water that will be charged into the pond must also be filtered and left in the pond for 3-4 days before stocking the fry. Make sure the salinity is 10-20 ppt.

Treatment

Change 10-30% of the pond water for 3 days in a row, apply slaked lime (CaOH)₂ at night with a concentration of 5-10 ppm, apply fermented bran and molasses with a ratio of 1:2 per 2 ppm for 3 days in a row until the pond water changes color, and apply probiotics such as Rhodococcus dan Rhodobacter at a concentration of 0.5-1 ppm in the evening.

Eradication

No information

Regulation and Other Information

No information

References

Alavandi, S.V., K.K. Vijayan, and K.V. Rajendran. 1995. Shrimp Disease, Their Prevention and Control. CIBA Bulletin No. 3. Madras.

Baticados, M.C.L. 1998. Disease. In: Biology and Culture of Penaeus monodon. SEAFDEC Aquaculture Department. pp. 139-178.

Center for Tropical and Subtropical Aquaculture. Prevention of Black Gill Disease in Marine Shrimp.

Dewangan,N.K., Gopalakrishnan, A., Kannan, D., Shettu, N., Singh, R.R. 2015. Black gill disease of Pacific white leg shrimp (Litopenaeus vannamei) by Aspergillus flavus. Journal of Coastal Life Medicine 3 (10): 761-765. doi: 10.12980

Srinivas, D., Ch. Venkatrayalu, and B. Laxmappa. 2016. Identifying diseases affecting farmed Litopenaeus vannamei in different areas of Nellore district in Andhra Pradesh, India. IJFAS 2016; 4(2): 447-451.

Symptoms and Treatment of Black Gill Disease in Shrimp. JALA.