Posthodiplostomum

Infobox Disease
ICD-10	G71.2
ICD-9	359.0
DiseasesDB	31991
MedlinePlus
eMedicine	neuro 76 neuro/230
MeSH ID

Posthodiplostomum is a genus of trematode parasites that primarily infects freshwater fish. The most notable species within this genus is Posthodiplostomum cuticola, which is known to cause black spot disease in fish.

Life Cycle

The life cycle of Posthodiplostomum involves multiple hosts. The adult parasites reside in the intestines of piscivorous birds, where they lay eggs that are excreted into the water. These eggs hatch into miracidia, which infect snails, the first intermediate host. Inside the snail, the miracidia develop into cercariae, which are released into the water and infect fish, the second intermediate host. In fish, the cercariae encyst as metacercariae under the skin, causing the characteristic black spots.

Symptoms and Diagnosis

Fish infected with Posthodiplostomum may exhibit black spots on their skin, which are actually the encysted metacercariae. This condition is commonly referred to as black spot disease. Diagnosis is typically made through microscopic examination of the encysted parasites in the fish tissue.

Treatment and Control

Treatment of Posthodiplostomum infections in fish can be challenging. Antiparasitic treatment may be used, but prevention through aquaculture management practices is more effective. This includes controlling snail populations and preventing bird access to fish ponds.

Impact on Aquaculture

Posthodiplostomum infections can lead to significant fish mortality, impacting aquaculture operations. Effective management and control strategies are essential to minimize economic losses.

See Also

• Trematode
• Parasitology
• Aquaculture