Interesting Clam Article

[sdcfish]

I thought this was an interesting article. I have seen bad shipments of Tridacna crocea clams in the past from a few bad shippers, but normally we don't have issues. I have a pretty strong feeling that stressed out clams from not being handled properly are the cause.

Best regards....Eric

http://www.medicalnewstoday.com:80/articles/103287.php

 

[swsaltwater]

wow also explains the tranship delays on them.

 

[Kalkbreath]

I saw this article a few weeks ago.....
First of all , Sure every time you mix pathogens from various geographic localities ......it can result in the same outcome as the white man bringing the small pox to our friends the Native American Indians.

But thats not what happened here with the case at Florida U

These clams died from their own bio fauna.
Or did they?

I dont know of any cultured clams out of Vietnam, do you Eric?
We need to establish if they were truly farmed clams or wild.
Because this event sound like a staged happining.
Sounds like an agenda: "Imported farmed clams Bad!" "American farmed clams good!

Maybe this was a way of covering her butt, instead of acknowledging her husbandry short comings .....blame the omnipresent pathogen.


Simply adding too much of any of a number of heavy metals like "Iron" to the captive system can stimulate Vibrio and other Protozoa populations to get out of hand and at the same time these metals cause stress on the bivalve to the point at which the health of the clam begins to fail......

Being that these clams were Deemed "cultured" and by definition farmed clams are less exposed to other worldly pathogens outside their local geography. ( the farm), why would have this particular group of clams died from a pathogen they have had all their clam lives?
More then likely these clams were cared for in less the ideal University systems or were exposed to outside pathogen sources like coming off wild clams at the point export /holding.

Ever notice how some retailers will post photos of themselves clam cherry picking at the wholesalers clam vat......only next time you see this , notice that most often several species of clams from around the world will be housed together in one system and placed together like at a preschool center for five year olds , they swap snot and gems to the point that each and every individual has been exposed to each and every other's micro biological cesspool of illness and ear infections.

A College researcher finding Perkinsus olseni living within Indonesian clams is hardly news.

Do a quick Google search , and you will establish that this has been a common observation for decades.

 

[JeremyR]

Someone send her all the threads on "pinch" and teach her about fw dipping so that they don't all die on her over "several months" next time.

 

[Anonymous]

I dont know of any cultured clams out of Vietnam, do you Eric?

I remember Jeff Majdali bringing in vietnamese clams that were supposed to have been farm grown, back around 2000 or 2001 or so. I seem to recall he had issues with the supplier so he only brought in a couple of shipments.

I can't vouch for whether they really were cultured or not, though.

 

[JeremyR]

There have been bazillions of vietnam croceas on the market for several years now, and generally speaking they are quite hardy. I've heard some people insist they are wild, and some they are farmed.. the colors & sizes are very uniform fwiw. It would be nice for people in the know to clarify this.

 

[chris&barb]

i suspect croceas comming in from Vietnam are wild. cites lists Vietnam as exporting between 35,000 to 45,000 wild croceas and 2,500 to 7,500 cultured per year but whether they are wild or cultured is provided by the exporter. regardless its pretty easy to tell a wild crocea from a cultured one by just looking at the shell and all of the ones ive seen are wild

 

[sdcfish]

Kalk,

You are correct to point out that the Florida report had tested "Aquacultured" clams". Now some one needs to clarify whether or not these clams are different than what the aquarium industry is importing.

I double checked our cites from Vietnam, and we are and have always been importing "Wild-Caught" crocea, maxima, squamosa clams. No aquacultured clams have made it this way.

We do get a consistent sizing in 2" up to 4" but I highly doubt any of the clams we receive are aquacultured.

So the questions are:

1. Is the study inaccurate or misleading?
2. Does the problem extend out to all clams? I would suspect yes.
3. Shall we contact them to clarify? I will....yes. Get back to ya'll.

 

[treeman]

Eric,

Also talk to Craig Watson. He was at MO 08 in Orlando and we talked about this there. There was a presentation on it but I don't remember who gave it.

 

[sdcfish]

Well.....I had a very nice conversation with the author Dr. Sheppard. I have invited her to visit this forum and participate. I think everyone will really appreciate her expertise and perspective.

Hope to see her soon! Stay tuned. If we don't hear from her shortly, I will share her comments to me on this thread.

Best regards.....

Eric

 

[spawner]

MO 2008 abstract

Voluntary quarantine program to establish Perkinsus-free stocks of imported Tridacnid clams in Florida

Craig A. Watson*, Denise Petty, and Kathleen Hartman
University of Florida
Tropical Aquaculture Laboratory
1408 24th Street S.E.
Ruskin, FL 33570

Tridacnid clams are an important marine ornamental mollusk imported into the U.S. from several Indo Pacific countries. In 2007, several Tridacna crocea were found to be infected with Perkinsus olseni, a protistan organism listed as a notifiable pathogen for molluscs by the World Organization for Animal Health (OIE). Prior to this finding P. olseni had not been reported in North America. After a meeting which included representatives from Federal and State of Florida agencies, University of Florida faculty, and representatives from relevant aquaculture industries, a plan was developed to establish a voluntary quarantine program which would allow for testing of quarantined Tridacnid clams to determine the presence or absence of Perkinsus spp. prior to distribution. Currently, there are no Federal health requirements for imported ornamental molluscs entering the U.S.; however, by appropriate quarantine procedures and testing the risk to commercial and wild susceptible livestocks is greatly minimized. This presentation will address concerns related to this pathogen as well as present an overview of the protocols recommended for quarantine and testing for Perkinsus in tridacnid clams.

 

[sdcfish]

Ok......

Dr. Sheppard has a few concerns about posting here on the forum after reading some of the comments, but has agreed to allow me to post her thoughts on the matter.

If we can have this discussion move forward in a civil manner, and work towards a common goal, then I think Dr. Sheppard and others will be more willing to participate here with us all. So here are her comments:

Dr. Sheppard Wrote:
They are correct that animals dying of something infectious, even if they are imported, is not a general cause for concern and does reflect stress (some of which is avoidable with expert husbandry). It would generally just make this a finding for us veterinary pathologists to like having a quick reference paper on so we knew quickly what it was and could move on to other work that day. That was the original reason for writing this up. The number of organisms and amount of tissue damage are absolutely spectacular and the finding helps to explain the mortality observed by hobbyists. Even heavily infected animals with severe tissue damage to their visceral mass structures have extended mantles and look fantastic until a day or two before becoming completely moribund and dying. This is a frequent pattern in chronic infections of pathogens, such as Perkinsus, which are highly adapted to their hosts. It is a solid practical strategy to avoid killing one's host.

Unfortunately, the thing that makes this finding the focus of wider interest is that this is a pathogen causing financial issues for shellfish industries in other parts of the world in a variety of shellfish hosts such as abalone in South Australia, cockles in New Zealand, etc.. That means that it has the potential (albeit unproven since it is not in US waters- knock on wood) to cause damage to our domestic ecosystems and associated oyster industries. For that reason, finding it meant that it had to be reported to the USDA and international authorities by the editor who is involved in policy regarding the oyster industry and international trade of shellfish. His concern reflects his extensive expertise in this organism and his concern for the people who could be affected.

Our domestic shellfish industries, while not typically interested in ornamental clams or their husbandry-associated diseases, already face economic hardship from the North American form of this pathogen called Perkinsus marinus which causes heavy losses during harvesting and hot weather. Their representatives are concerned by the possibility that the Indo-Pacific form of the pathogen, P. olseni, has a potential source of entry in the form of ornamental clams. As you know, ornamental species are not subject to the testing etc experienced by the heavily regulated shellfish industries in our country.

Although hobbyists will point out that they discard their tank water down a drain leading to a water sanitation system of some type with virtually no exceptions, the presence of exotic species of animals and plants in various habitats including the Everglades and domestic waters is well-documented and solidly linked to inappropriate releases by the public.
The EU, for example, can request restrictions on export of live agricultural products citing concerns over the pathogen status of the US. That means a loss of revenue. The shellfish industry, and possibly environmentalists, may request new restrictions for entry of animals with pathogens that endanger their industry and foreign trade. This is reflected in voluntary efforts spear-headed by a consortium of USDA and industry stakeholders in Florida to test for Perkinsus. Heavy infections of this pathogen have subsequently been found in many T. crocea tested from 2005 to the present even upon immediate arrival. Perkinsus, a single cell protozoa with some physical similarities to organisms such as intestinal coccidia and malaria, is a chronic pathogen which infects animals long-term with rapid increases in the associated morbidity and mortality when the host is stressed. This means that the hosts arrive infected regardless of the good intentions of the importers or the husbandry skills of the consumer. It is a pathogen causing disease and is not a component of normal flora. It is not a bacteria or fungus and is not found long-term in water lacking an appropriate host.

The effect of the pathogen on the ornamental clams, while important to people who sell, buy and enjoy beautiful tridacnid clams, is of absolutely no significance to the shellfish industry or our foreign trading partners. The issue is based completely on their role as hosts to a foreign pathogen which could impact our domestic shellfish industries and acceptance of our products by international trading partners that have stricter regulations. Vietnam's geographical proximity to the P. olseni-infected waters of China and the Gulf of Thailand makes the finding of P. olseni in shellfish living in Vietnamese waters less than surprising, although unfortunate as their T. crocea are genuinely beautiful.

The original set of T. crocea are designated as aquacultured, a designation devoid of political meaning by the author, due to their origin from facilities maintained by those regional industries although it is my understanding that the stocks are collected from the wild; their exposure to the infected waters of that region whether during time spent in the wild or a contained area is the key element. Any clams co-housed with an infected clam can become infected and the water will contain infectious forms- this is because every known life stage of P. olseni is infectious, it does not require intermediate hosts such as snails or fish to replicate, and it releases infectious forms into the water while alive from its damaged internal tissues and after dying.

Identifying a source of tridacnids from a geographical location that does not have endemic P. olseni (perhaps isolated islands?) would be a constructive focus for the ornamental industry and its supporters.

I encourage your participants to move past their initial frustrations to become aware of the core issues, help find alternatives, and seek to educate enthusiasts on safe disposal of water/carcasses. I can make recommendations with regard to hygiene and potential strategies for removal of the organism based on its biology if requested. I believe your industry leaders and the hobbyists can make a positive impact on future decisions if they move forward in these areas.

I appreciate your making the step to call me and I hope I can help you all find some good alternative sources.
Thanks again,
B

Ok...me again....Pretty deep stuff there, and honestly I feel that we need to work with some suppliers to gather specimen samples from many regions, to do more studies. Dr. Sheppard was willing to do the lab work to further the study. Seems like this nasty pathogen is region specific, so if we can prove that same species are not all infected, then we stand a chance to continue importation. I have discussed this with the good Doctor and we have a plan on how to handle water samples, tissue samples and specimens etc.....

Open for comment.

 

[Kalkbreath]

This answers their agenda.......
But I have a few more ideas to ponder.
Why the Croceas clams died in their custody?
All Veitnam Croceas pretty much carry this particular Protazoa but not all die form it in such rapid succession asin their lab.
What did the University do to set off the Perkinsus?( tap water high in lead will do it)
Does the Author have any thoughts as to why Croceas in the wilds of Vietnam dont seem to have the rampant mortalities stemming from Perkinsus
as they (the UF) do in their Florida labs?

How about a microscope video of Perkinsus activly causing tissue damage to the clams, for all of us pseudo intellectuals out here?

The cause of death by Perkinsus is usually by suffocation as the population gets so extreme/great that the micro basterds agitate the clams gills and this over stimulates mucus production by the bivalve and this chokes off the gills ability to carry out proper respiration.( gaping)
A tridacna's tissue begins to decompose pretty quickly after death.(every hobbyist who looses a clam knows this and the odd smell only a rotting clam can emit){Dimethylsulfoniopropionate}

If the clams died prior to being examined, how can you be sure the tissue damage was not simply due to this quite normal rapid decomposition?


The chances of Perkinsus surviving a freshwater sewer treatment plant
is about the same as Nemo making it through the Sidney system.
(but who pays attention to hypo salinity anyhow?)(I saw it in a movie so it must be true)

Prove Perkinsus able to stand a stint through a sewage plant and you might have plausible room for concern.

And lastly please share the University's thoughts on why "Pinched Mantel"
only shows up in certain circles of the trade?

 

[chris&barb]

And lastly please share the University's thoughts on why "Pinched Mantel"
only shows up in certain circles of the trade?

what circles would that be? Ive read and participated in just about every pinched mantle thread i could fine on the net since the name pinched mantle was coined. Ive corresponded with people from the US, Canada, UK, Germany, Hong Kong, Singapore and Kuwait that have had it. Thats a big circle.

 

[JeremyR]

FWIW, the oscars in the everglades are because misguided people let unwanted fish go , and our wonderful govt introduced various non-natives intentionally for one reason or another. I'm not sure how many people are returning their clams to the ocean, I don't think people have the same "give it a better life" feeling for them.

 

[Anonymous]

FWIW, the oscars in the everglades are because misguided people let unwanted fish go , and our wonderful govt introduced various non-natives intentionally for one reason or another. I'm not sure how many people are returning their clams to the ocean, I don't think people have the same "give it a better life" feeling for them.

Tilapias to eat the excess vegetation from nutrient runoff, Peacock bass to eat the excess tilapias and oscars, of course the peacock bass loves to eat largemouth bass. I wonder what they will introduce next to eat the peacock bass.

 

[Caterham]

I dont know whether the crocea clams coming out of Vietnam are cultured or not. I do know that I lose less than 10 for every 1000 that I bring in.

The less colorful ones end up staying with me for an extended period of time and they do fantastic. No problems whatsoever. I love the clams out of Vietnam.

 

[sdcfish]

Here is the link for the OIE (French for "international animal health organization") website and for the pages specifically about P. olseni (the pathogen not known to be in the USA/Canada) and P. marinus (the pathogen affecting the oyster industry in the USA). These pages provide a wealth information about the organisms which are both extremely well-studied and documented due to their economic importance.

Note that the Vietnamese T. crocea have a dual infection with P. olseni and a previously uncharacterized putative new species of Perkinsus. The observation of dual Perkinsus infections in shellfish in Japan, China, and Vietnam may reflect the highly adaptive character of this pathogen once chronically established in a host. That "new" Vietnamese species is not internationally reportable but is a concern as no one has data on whether it can infect our domestic oysters thereby giving no solid basis for an informed assessment of risk. I have those studies underway. T. crocea have been submitted to a few of my veterinary colleagues at different diagnostic labs in at least two other states over the past few years by unhappy and curious owners - the diagnosticians suspected or verified a heavy infection with an organism but were unable to fully characterize it (genetically etc). My samples were fresh and I sacrificed some animals to get optimal samples. Diagnostics including genetic techniques have been exhaustively repeated by my lab and the international reference lab to verify the presence of the pathogens.

OIE website with lists of internationally reportable pathogens and links to chapters describing each pathogen: http://www.oie.int/eng/normes/fmanual/A_summry.htm

P. olseni page: http://www.oie.int/eng/normes/fmanual/A_00043.htm

P. marinus page: http://www.oie.int/eng/normes/fmanual/A_00042.htm

Cheers,
B

 

[JeremyR]

I would like to see clarification as to whether these clams were a direct tranship from vietnam, or whether they were mixed with other clams at any point in LA, and if so where.

 

[sdcfish]

Jeremy,

What I remember her telling me, is that she got the clams from a Tampa, Florida based wholesaler. The clams were thriving in their reef system for well over 30 days before the studies were done. They did notice that one clam showed signs of stress, the others also began to look bad too within days of each other. I have seen that reaction too.

What was interesting that I don't think I mentioned yet, is that the term "Aquacultured" could also mean "grown-out". I think it's more important to know whether the specimens were in contact with natural seawater rather than if they were hatched in captivity.

We are to receive tomorrow a new batch of T. crocea, and we have our biologist do some necropsy study's and see if we can find the same Perkinsus. More to come.....stay tuned.

Best regards