Lifestyle of a killer

Sep 06, 2012
Parasitic dinoflagellates of the genus Hematodinium are a big problem for crab, prawn and shrimp fisheries across the world. Credit: Dr. Grant Stentiford

Parasitic dinoflagellates of the genus Hematodinium are a big problem for crab, prawn and shrimp fisheries across the world. New research published in BioMed Central's open access journal Aquatic Biosystems has found that, in wild European brown shrimp (Crangon crangon), these parasites have bacteria-like endosymbionts. The presence of these endosymbionts indicates a previously unknown side to the lifecycle of Hematodinium.

Hematodinium sp. and its sister species H. Perezi are a real problem for blue crab fishers , causing 'bitter crab' disease, and are thought to be responsible for the decline of in . But they are not fussy. Over 40 species of crustaceans are known to be infected by these nasty parasites.

A collaboration between researchers at the European Union Reference Laboratory for Crustacean Diseases (CEFAS) and the Virginia Institute of Marine Sciences (VIMS) identified the parasite responsible for causing sickness in wild European brown shrimp, collected from the North Sea, as Hematodinium sp.. These shrimp had lost carapace transparency and their blood (haemolymph) had lost the ability to clot. The invading Hematodinium had also infiltrated the muscles, destroyed , and the infection had damaged the shrimp's ovaries, affecting their ability to reproduce. Adding insult to injury the shrimp were also infected with Crangon crangon bacilliform virus (CcBV).

Further investigation revealed that two of the lifestages of the parasite were present in these shrimp, trophont (the adult, mobile stage) and dinospore (the infectious stage). However, for the first time, the dinospores were themselves seen to be infected with bacteria-like cells both in the cytoplasm and inside the nucleus.

Dr Grant Stentiford from Cefas explained, "The inside Hematodinium sp. appeared to make no difference to the ability of the parasite to infect shrimp. However, for these relationships to survive the endosymbiont must supply an evolutionary advantage. It seems most probable that the endosymbiont in some way increases the chance of the dinoflagellate to survive outside the shrimp, and successfully transfer to a new host. One of the problems with Hematodinium infection is that we do not yet fully understand their lifecycles. The role of this endosymbiont to its survival may be the key to controlling infections in species of farmed crustaceans."

Explore further: Deep sea fish eyesight similar to human vision

More information: Hematodinium sp. and its bacteria-like endosymbiont in European brown shrimp (Crangon crangon) Grant D Stentiford, Kelly S Bateman, Michelle Pond, Hamish J Small and Anette Ungfors, Aquatic Biosystems (in press)

add to favorites email to friend print save as pdf

Related Stories

New shrimp species found in Queensland waterhole

Apr 07, 2011

(PhysOrg.com) -- With the torrential downpours in Queensland this year roadside waterholes are abundant, and it is in one of these waterholes that professor Brian Timms has discovered a new species of shrimp. ...

Invasive Parasite Spreading Among West Coast Estuaries

Feb 26, 2009

(PhysOrg.com) -- A parasitic isopod that scientists identified five years ago has all but decimated mud shrimp populations in coastal estuaries ranging from British Columbia to northern California - with the ...

US tiger shrimp sightings worry scientists

Apr 27, 2012

(AP) -- A big increase in reports of Asian tiger shrimp along the U.S. Southeast coast and in the Gulf of Mexico has federal biologists worried the species is encroaching on native species' territory.

Tiny Shrimp Help to Fine-Tune National Defense

May 10, 2006

Research being conducted by UMaine researcher Peter Jumars of the Darling Marine Center and UMaine School of Marine Sciences has created an unlikely pairing between the U.S. Department of Defense and a tiny ocean-going creature ...

Recommended for you

Male sex organ distinguishes 30 millipede species

12 hours ago

The unique shapes of male sex organs have helped describe thirty new millipede species from the Great Western Woodlands in the Goldfields, the largest area of relatively undisturbed Mediterranean climate ...

Dogs hear our words and how we say them

Nov 26, 2014

When people hear another person talking to them, they respond not only to what is being said—those consonants and vowels strung together into words and sentences—but also to other features of that speech—the ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.