Nematodes in CB SH

[Labdoc]

I found this parasite in the tail of a CB SH. First time in over 60 cases I have seen such a finding in a CB horse. Does anyone have any information on the subject?

http://forum.seahorse.org/index.php?act=Attach&type=post&id=12903

 

[LisaD]

Do you know the history of the seahorse? Was it kept with wild caught fish in a tank? I suppose it is possible for breeding stock of CB seahorses to carry and pass on non-lethal parasites.

 

[Labdoc]

This is what the owner told me.

I have a 54 gal tank that has been set up about 5 years. About a year ago I noticed a growth on one of my horses. It started as a swollen spike on the tail and then grew larger. See the Pic for image. Now they have spread. This horse has 2 growths, and I have spotted a few starting on my other horses. I've quarintined and treated with Kanacyn and also Tetracyclin at different times. Neither seemed to make much difference.

Salinity - 1.021
Ammonia - 0 (Red Sea Test Kit)
Nitrite - 0.1 ( a little high, for normal)(Red Sea Test Kit)
PH - .78 (Red Sea Test Kit)
KH/Alkalinity 0.5 ml, 8.0 dKH, 2.86 meg/L (Salifert Test Kit)
calcium 350 ppm (Salifert Test Kit)
Nitrate 20-50 ppm (Red Sea Test Kit)
temp 74 deg F

I noticed the water back from the sump had a little too low pressure and found the filter in the pump inlet was dirty so I cleaned it out, and now back to normal flow. Probably the reason for higher than normal Nitrate and Nitrite

4) I've had seahorses for 5 years but bought the last 4 new ones from X about a year ago.

5) I have all captive breed

6) Seahorses were purchased from X

7) I feed them frozen Mysis and Vibrance II from OR. No change in feeding behavior.

They also said they got rare WC shrimp feedings and felt that's when the problem started but not exactly sure of the time frame.

 

[Samala]

Well.. how likely is it that the parasites are reproducing and being deposited in fecal matter, hatching and then reinfecting the other SH? Or is it more likely/do you feel the parasites are being vectored in by WC shrimp feedings that are normal reservoirs for the nematodes in question? I find nematode reservoirs tend to be snails in marine environments, but I imagine shrimp could serve this role as well. Personally I would think the shrimp are the most likely way into the SH. But then they have to find their way into the various positions in the SH.. as you said the tail.

Thanks for sharing the info though, its at least a heads up that it can happen.

>Sarah

 

[Labdoc]

I agree with you, the shrimp are the most likely vector in this situation but without good epidemiological evidence I can't make that claim. I'm very interested to know if there are any other reports of this or better yet some form of ID. There was also an unusual epithelial hyperplasia in the skin lesions.

http://forum.seahorse.org/index.php?act=Attach&type=post&id=12906

http://forum.seahorse.org/index.php?act=Attach&type=post&id=12905

The normal SH skin is only a few cells thick.

http://forum.seahorse.org/index.php?act=Attach&type=post&id=12904

I also thought about relating the two via some sort of cercarial transmission but I am most familiar with human diseases so I have no knowledge base to refer to.

 

[Samala]

Unfortunately I dont do much work in pathology for marine organisms either. I know of a few parasites and reservoir species mainly for human health concerns with laboratory animals actually. Such as cercarial transmission for Ilyanassa obsoleta to seagulls of a nematode parasite. And another fluke type parasite carried by the same snail causing human swimmers itch. There are a few cases in freshwater for this pathway from snails to fish.. I'll post if I can find ref's online because the specifics of them evade me. Its been too long since I had those classes.

The hyperplasia may just be scar tissue forming around the embedded parasite, yes? If the skin lesions were in contact with the parasite that would be my guess as to cause. That in itself isnt too uncommon with terrestrial host/parasite reactions.

This all makes me very thankful that I was screening WC grass shrimp and subjecting them to anti-helminthics before using them in larval culturing tanks for SH.

>Sarah

 

[Labdoc]

The hyperplasia may just be scar tissue forming around the embedded parasite, yes? If the skin lesions were in contact with the parasite that would be my guess as to cause.

Very possible. Thank you so much for the input. I can't find any in-depth texts on these subjects.

 

[LisaD]

both of you lost me some time ago, but I get the idea you think the parasite came in on WC feeder shrimp. would killing and freezing ghost shrimp reduce the risk of transmission?

 

[Samala]

Lisa.. this got a bit buried before I saw your last post.. basically I think that the WC shrimp are carrying in the parasites, just as you said. Labdoc agrees its possible. Unfortunately I havent found anything in my resources about parasite transmission through a reservoir (like the shrimp) to marine fishes (like the SH). The ones for freshwater fish dont seem to apply. I was hoping since grass shrimp tend to be used often in bioassay work there would be something on any parasites they carry, but I havent found much other than flukes.

Freezing the shrimp after sacrificing might downplay the risk of parasites, but I.. as a rule.. treat all wc shrimp (grass, etc) to an anti-nematode/parasitic drug for at least a week before feeding out. I had the advantage of not bringing in lots of shrimp since I was mostly holding them for breeding. This might get tricky if you rely on WC shrimp for a dietary staple. IE: you'd have to know when you were down to a weeks' worth so you could start a new round of quarantined and treated shrimp.

I think all sushi grade food fish are flash frozen to kill parasites.. or maybe I have finally lost my marbles. I seem to remember reading that somewhere.

PS: Did you work out a program for the zebras/glofish? I could keep it in mind and see if any good ideas spring up.

>Sarah

 

[Labdoc]

Flash freezing is practiced in most Sushi restaurants, can't find statistics on how prevelent it is. It does cut down on the number of living parasites. Other strategies include the carefull selection of what is called "Sushi Grade Fish" which supposedly carries fewer parasites. Most SW fish parasites can not be transmitted to humans. One that can is Anisakiasis which is a parasitic disease contracted from infected seafood which is eaten raw or marinated. This is a type of round worm which can be picked up from eating sashimi, sushi, and ceviche.

Symptoms are variable and can range from an acute syndrome with nausea and vomiting, abdominal pain or diarrhea within 12 hours of eating infected seafood to other problems which can last weeks to months. Anisakiasis can mimic other diseases, such as acute appendicitis, stomach tumors, and inflammatory bowel disease.

Fewer than 30 cases of illnesses resulting from the presence of parasites in sushi or sashimi were reported in the U.S. during 1986, and most were on the West Coast. More fish are infected -- and therefore more humans -- on the West Coast than the East because the primary hosts for the parasites are marine animals commonly found in the Pacific, such as seals, porpoises, sea lions and whales

It's important to remember that adequate freezing and/or cooking eliminates infection by the parasites. In commercial freezing, a temperature of -40 Ã"šÃ‚°F kills any parasite in 15 hours. In a home freezer, at 0Ã"šÃ‚° to 10Ã"šÃ‚°F, it can take up to five days to kill all the parasites, especially in large fish.