Haplosporidian Infections of Penaeid Shrimp


Category 3 (Host Not in Canada)

Common, generally accepted names of the organism or disease agent

Haplosporidian infections, Hepatopancreatic haplosporidiosis.

Scientific name or taxonomic affiliation

One or more haplosporidians have been recognized in penaeid shrimp. However, spore stages have not yet been encountered and insufficient taxonomic investigations have been conducted to identify the precise taxonomic position in the phylum Haplosporea.

Geographic distribution

  1. Cuba and Nicaragua.
  2. Mexico.
  3. Indonesia and the Philippines.

Host species

  1. Penaeus vannamei.
  2. Penaeus stylirostris.
  3. Penaeus monodon.

Impact on the host

Affects on host have not been documented. The first report was made in 1988 in juvenile P. vannamei imported from Nicaragua and held in quarantine in Cuba where it was reported to be highly pathogenic (Dykova et al. 1988). The infection in P. stylirostris were found in individuals with terminal microsporidiosis (with Amesoma).

Diagnostic techniques

Histology: Multinucleate plasmodia found apically or laterally to the nucleus in hepatopancreatic tubule epithelial cells. The plasmodia may fragment into many uninucleate stages that can occur in the tubule lumen. Heavily infected tubules are typically surrounded by masses of haemocytes which are actively encapsulating and melanizing the affected portions of the hepatopancrease.

Methods of control

No known methods of prevention or control.


Dykov, I., J. Lom and E. Fajer. 1988. A new haplosporean infecting the hepatopancreas in the penaeid shrimp, Penaeus vannamei. Journal of Fish Diseases 11: 15-22.

Lightner, D.V. (ed.). 1996. A Handbook of Shrimp Pathology and Diagnostic Procedures for Disease of Cultured Penaeid Shrimp. World Aquaculture Society, Baton Rouge.

Citation Information

Bower, S.M. (1996): Synopsis of Infectious Diseases and Parasites of Commercially Exploited Shellfish: Haplosporidian Infections of Penaeid Shrimp.

Date last revised: September 1996
Comments to Susan Bower

Date modified: