Synopsis of Infectious Diseases and Parasites of Commercially Exploited Shellfish

Hematodinium perezi and Hematodinium sp. of Atlantic Crabs

Category | Common Name | Scientific Name | Distribution | Host Species
Impact on Host | Diagnostic Technique | Methods of Control | References | Citation

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Category

Category 1 (Not Reported in Canada)

Common, generally accepted names of the organism or disease agent

Hematodinium perezi, Dinoflagellate blood disease.

Scientific name or taxonomic affiliation

Hematodinium perezi and Hematodinium sp.

Geographic distribution

a) European waters.
b) East and Gulf coasts of the United States from Delaware to Texas.

Host species

a) Carcinus maenas, Cancer pagurus, Portunus depurator and Necora (=Liocarcinus) puber.
b) Callinectes sapidus, Callinectes similis, Cancer irroratus, Cancer borealis, Ovalipes oscellatus, Carcinus maenas.

Note: Hematodinium spp. have been described from other marine crustaceans including other species of crabs from the vicinity of Australia and Chionecetes spp. from the north Pacific and north Atlantic oceans, as well as from lobsters and shrimp.

Impact on the host

Infections are usually low in prevalence. However, prevalence of about 50% with associated mortalities were reported in Cancer pagurus from the vicinity of Portsall, France, prevalences up to 87% were observed in Necora puber from Brittany, France. Prevalences up to 40% were detected in Callinectes sapidus from Florida, USA (Messick and Shields 2000). May cause high mortalities among C. sapidus (from salinities above 11 ppt) in enzootic areas along the east coast of North America and was suspected of causing mass mortalities of N. puber in Mor-Braz (south Brittany, France). Results from preliminary surveys using a PCR diagnostic technique suggested that Hematodinium sp. was absent in C. sapidus from low salinity waters (5 to 10 ppt) but common in C. sapidus from higher salinity estuarine waters in southeastern Georgia, USA (Gruebl et al. 2002). This parasite is believed to represent a significant threat to C. sapidus fisheries in high salinity estuaries and may have a greater effect on mature females that move to higher salinities to breed. Infection can be artificially transmitted between C. sapidus by injection (Shields and Squyars 1999).

Diagnostic techniques

Gross Observations: Lethargy. Haemolymph of heavily infected crabs is opalescent and slow to clot.

Wet Mounts: Haemolymph devoid of haemocytes, filled with non-motile dinoflagellates.

Smears: Vegetative stages (5.8-6.4 µm) containing one or more nuclei that are large in proportion to cytoplasmic volume with either condensed or diffused chromosomes of the characteristic dinokaryon nucleus.

Histology: Numerous non-motile vegetative stages and few haemocytes in the haemal spaces of all tissues. Total lysis of hepatopancreatic tubules and partial destruction of muscle fibres may occur.

DNA Probes: The development of a PCR-based diagnostic test and identification of DNA probes for in situ hybridisation of paraffin embedded host tissues were investigated by Hudson and Adlard (1994) and Hudson et al. (2001), respectively. An 18S rRNA gene-targeted PCR-based diagnostic technique capable of detecting 1 Hematodinium sp. in 300,000 haemocytes of Callinectes sapidus was described by Gruebl et al. (2002).

Methods of control

No known methods of prevention or control.

References

Chatton, E. and R. Poisson. 1930. Sur l'existence dans le sang des crabes, de péridiniens parasites: Hematodinium perezi n.g., n.sp. (Syndinidae). Comptes Rendus des Séances de la Societé de Biologie et de ses Filiales 105: 553-557. (In French).

Couch, J.A. 1983. Diseases caused by protozoa. In: A.J. Provenzano Jr. (ed.). The Biology of Crustacea. Volume 6, Pathobiology. Academic Press, New York, p. 79-111.

Gruebl, T., M.E. Frischer, M. Sheppard, M. Neumann, A.N. Maurer and R.F. Lee. 2002. Development of an 18SrRNA gene-targeted PCR-based diagnostic for the blue crab parasite Hematodinium sp. Diseases of Aquatic Organisms 49: 61-70.

Hudson, D.A. and R.D. Adlard. 1994. PCR techniques applied to Hematodinium spp. and Hematodinium-like dinoflagellates in decapod crustaceans. Diseases of Aquatic Organisms 20: 203-206.

Hudson, K.L., J.D. Shields and K.S. Reece. 2001. Molecular diagnostics for the parasitic dinoflagellate Hematodinium perezi. Journal of Shellfish Research 20: 546. (Abstract).

Latrouite, D., Y. Morizur, P. Noël, D. Chagot and G. Wilhelm. 1988. Mortalite du tourteau Cancer pagurus provoquee par le dinoflagelle parasite: Hematodinium sp. International Council for Exploration of the Sea, Shellfish Committee CM.1988/K: 32: 11 pp. (In French with English abstract).

MacLean, S.A. and C.L. Ruddell. 1978. Three new crustacean hosts for the parasitic dinoflagellate Hematodinium perezi (Dinoflagellata: Syndinidae). Journal of Parasitology 64: 158-160.

Messick, G.A. and J.D. Shields. 2000. Epizootiology of the parasitic dinoflagellate Hematodinium sp. in the American blue crab Callinectes sapidus. Diseases of Aquatic Organisms 43: 139-152.

Messick, G.A. and C.J. Sindermann. 1992. Synopsis of principal diseases of the blue crab, Callinectes sapidus. NOAA Technical Memorandum NMFS-F/NEC-88. 24 p.

Newman, M.W. and C.A. Johnson. 1975. A disease of blue crabs (Callinectes sapidus) caused by a parasitic dinoflagellate, Hematodinium sp. Journal of Parasitology 61: 554-557.

Shields, J.D. 1994. The parasitic dinoflagellates of marine crustaceans. Annual Review of Fish Diseases 4: 241-271.

Shields, J.D. 1999. Partial culture and cryopreservation of the parasitic dinoflagellate Hematodinium perezi from the blue crab. Journal of Shellfish Research 18: 334. (Abstract).

Shields, J.D. and C.M. Squyars. 1999. Hematology of blue crabs, Callinectes sapidus, infected with the parasitic dinoflagellate Hematodinium perezi. Journal of Shellfish Research 18: 325. (Abstract).

Shields, J.D., C. Scanlon and A. Volety. 2003. Aspects of the pathophysiology of blue crabs, Callinectes sapidus, infected with the parasitic dinoflagellate Hematodinium perezi. Bulletin of Marine Science 72: 519-535.

Wilhelm, G. and V. Boulo. 1988. Infection de l'etrille Liocarcinus puber (L.) par un dinoflagelle parasite de type Hematodinium sp. International Council for Exploration of the Sea, Shellfish Committee CM.1988/K41: 9 p.

Wilhelm, G. and E. Mialhe. 1996. Dinoflagellate infection associated with the decline of Necora puber crab populations in France. Diseases of Aquatic Organisms 26: 213-219.

 

Citation Information

Bower, S.M. (2003): Synopsis of Infectious Diseases and Parasites of Commercially Exploited Shellfish: Hematodinium perezi and Hematodinium sp. of Atlantic Crabs.

URL: http://www.pac.dfo-mpo.gc.ca/science/species-especes/shellfish-coquillages/diseases-maladies/pages/hphacb-eng.htm

Date last revised:   June 2003
Comments to Susan Bower