FunkieReefJunkie
Member
Well I've now suffered two dead clams due to the clam pinching protozoan. One clam is still undergoing metro treatment. With all that I've learned today about protozoa I'm not sure what to do with him if he pulls through. Can't put him back in the main tank and risk re-infestation. Had I known about this protozoan I would have never purchased the new one which introduced it. The word hasn't got out to everyone yet and this saddens me. Pyramidellid snails have nothing on these guys. They're far more challenging to deal with.
Whatever protozoan this is, it is nasty. Protozoans can become encysted, that is, the cell may assume a fairly round or oval shape and secrete a protective coating around itself. At this stage, the cell may survive a lack of food or moisture, adverse temperature changes, or contact with toxic chemical agents. With a return to favorable conditions, water is absorbed into the cyst, and the organism emerges and resumes its growth. Protozoa result in infection in animals causing chronic to acute disease. Part of the life cycle can start in one animal, and another stage of the cycle in a different host. The guys in our tanks are probably flagellating, i.e., swimming about.
A few protozoans that have wreaked havoc on clams across the globe:
Staten Island(March 23, 2003) = Q.P.X. (Quahog Parasite Unknown), a protozoan that infects a clam's soft tissue, causing an inflammation that prevents it from closing its shell so it becomes unable to pump water, and the bits of nutrients suspended in the water, through its filtering gills. Fatal to clams.
Korea (1996) = Perkinsosis is a shellfish disease caused by a parasitic protozoan in some commercially imported mollusks including oysters, clams, abalones and scallops. Often results in mass mortalities. In Korean waters, Perkinsus sp. has been found in the manila clam, Ruditapes philippinarum. Perkisus trophozited are distributed commonly in gills, digestive glands, mantle and gonadal connective tissues. Relatively scarce in foot and siphons. Studies showed Perkinsus sp. discovered in the clam in Korea could be P. atlanticus in European waters. Highest mortalities during spawning.
Perkinsus marinus and P. olseni/atlanticus = protistan parasites of the genus Perkinsus. Perkinsus is not in the phylum Apocomplexa, but is closely related to the Dinoflagellida. Some authors have placed Perkinsus in the phylum Perkinsozoa, or the phylum Dinozoa subphylum Protalveolata. Although in infection of C. gigas and C. ariakensis is possible, these species seem to be more resistant to the disease. Perkinsus marinus was formerly named Dermocystidium marinum, and then Labyrinthomyxa. Infection by P. marinus is commonly known as Dermo disease. Perkinsus marinus is found on the east coast of the USA from Maine to Florida, and along the Gulf of Mexico coast to the Yucatan Peninsula. In C. virginica the effects range from a pale appearance of the digestive track gland and reduction in condition index, to severe emaciation, gaping, retraction of the mantle, inhibition of gonadal development, retarded growth, and death. Perkinsus olseni was originally described in Australia and P. atlanticus in Portugal. The geographical distribution of P. olseni/atalanticus is eastern and southern Australia, New Zealand, Korea, Japan, Portugal, France, Italy and Spain.
All this has been interesting but frustrating for me to absorb. I'd like to see more information, maybe an article on RKM.
Whatever protozoan this is, it is nasty. Protozoans can become encysted, that is, the cell may assume a fairly round or oval shape and secrete a protective coating around itself. At this stage, the cell may survive a lack of food or moisture, adverse temperature changes, or contact with toxic chemical agents. With a return to favorable conditions, water is absorbed into the cyst, and the organism emerges and resumes its growth. Protozoa result in infection in animals causing chronic to acute disease. Part of the life cycle can start in one animal, and another stage of the cycle in a different host. The guys in our tanks are probably flagellating, i.e., swimming about.
A few protozoans that have wreaked havoc on clams across the globe:
Staten Island(March 23, 2003) = Q.P.X. (Quahog Parasite Unknown), a protozoan that infects a clam's soft tissue, causing an inflammation that prevents it from closing its shell so it becomes unable to pump water, and the bits of nutrients suspended in the water, through its filtering gills. Fatal to clams.
Korea (1996) = Perkinsosis is a shellfish disease caused by a parasitic protozoan in some commercially imported mollusks including oysters, clams, abalones and scallops. Often results in mass mortalities. In Korean waters, Perkinsus sp. has been found in the manila clam, Ruditapes philippinarum. Perkisus trophozited are distributed commonly in gills, digestive glands, mantle and gonadal connective tissues. Relatively scarce in foot and siphons. Studies showed Perkinsus sp. discovered in the clam in Korea could be P. atlanticus in European waters. Highest mortalities during spawning.
Perkinsus marinus and P. olseni/atlanticus = protistan parasites of the genus Perkinsus. Perkinsus is not in the phylum Apocomplexa, but is closely related to the Dinoflagellida. Some authors have placed Perkinsus in the phylum Perkinsozoa, or the phylum Dinozoa subphylum Protalveolata. Although in infection of C. gigas and C. ariakensis is possible, these species seem to be more resistant to the disease. Perkinsus marinus was formerly named Dermocystidium marinum, and then Labyrinthomyxa. Infection by P. marinus is commonly known as Dermo disease. Perkinsus marinus is found on the east coast of the USA from Maine to Florida, and along the Gulf of Mexico coast to the Yucatan Peninsula. In C. virginica the effects range from a pale appearance of the digestive track gland and reduction in condition index, to severe emaciation, gaping, retraction of the mantle, inhibition of gonadal development, retarded growth, and death. Perkinsus olseni was originally described in Australia and P. atlanticus in Portugal. The geographical distribution of P. olseni/atalanticus is eastern and southern Australia, New Zealand, Korea, Japan, Portugal, France, Italy and Spain.
All this has been interesting but frustrating for me to absorb. I'd like to see more information, maybe an article on RKM.
