Hermit crabs, human hlth.  5/1/08
Hi
I just have a few quick questions. My daughter is very ill and can not be around any disease carrying pets someone suggested a hermit crab to her and she has been searching to see if she can have one. Do they carry any diseases that can be transmitted to humans?
<Mmm, not unless the human is badly challenged immunity wise... some waste bacteria...>
Are they expensive to take care of?
<Mmm, no>
I hope to hear form you soon. I would like to purchase a couple as soon as I know if they are safe for her because we don't know how much longer she will be with us and I want to give her what ever she wants but sometimes I can't. She is just recently without her dog due to this illness and now she just wants something she can love. Also if they are safe where is the most reputable place to buy them? I only have corporate pet stores near me like Pet smart and Pet co.
<Some of these (due to individual staff) are excellent. I would visit, engage them in conversation... purchase a small book on Hermit husbandry, read it with your child. Oh, and do read here: http://wetwebmedia.com/FWSubWebIndex/hermitcrabfaqs.htm
for some general care input>
Thank you
Valeri
<Welcome. Bob Fenner>

Zoanthids, palytoxin, human contact  4/9/08
Mr. Fenner,
I have a disease called scleroderma that effects my autoimmune process and need to be cautious. I have read about the neurotoxin called palytoxin that occurs with Zoanthid polyps. I read about the need for caution and it's effects but on the other hand I get the impression its occurrence in the aquarium hobby seems rare. With this in mind I have what I believe is a Zoanthid Palythoa that looks like the common type with green polyps. I'm new to the hobby and need to know if I have a serious concern. I intend to use gloves if the need comes to physical touch it, but do I need to be concerned about making contact with the aquarium water with my hands.
Your input will be appreciated.
Steve C.
<Mmm, always best to be cautious when dealing with Zoanthids... particularly in handling directly, as in asexual propagation/cutting. I do advise that you, actually most everyone wear good gloves whenever they place their hands in their tanks... to prevent possible troubles for themselves during exposure, as well as to disallow contamination. Cheers, Bob Fenner>

Help - my son ingested Tri-start!! – 03/13/08
Hi
I have a fresh water aquarium and treat my water with Tri-start when I do a water change. Today my two year old son got into my fish equipment cupboard and had a sip of my tri-start. I panicked and called poisons info (I am in Australia) but they couldn't find any information on the ingredients of tri-start. They did eventually find one database that said water conditioners are mostly sodium chloride. I was wondering if you could tell me if that is the case, and if not, what the main ingredients are for Tri-start or similar products.
So far my son seems fine but I am worried and surprised that manufacturers do not have to list at least an active constituent. The poor man at poisons agreed as it makes their job very difficult!
Thanks a lot. Hope you can help me.
Regards
Sarah
<Sarah, water conditioners -- dechlorinators -- are mostly sodium thiosulphate. That's what you need to tell your medical practitioner. My understanding is that sodium thiosulphate is relatively harmless unless consumed in large amounts, though it is an irritant and emetic, and you should certainly get in touch with your MD. Cheers, Neale.>

IMPORTANT .....my cat drank medicated fish water!! 01/26/2008
NEED INFO:
<<Hello, Andrew here>>
I turned my back for one second, and my cat was drinking the medicated fish water I'd just prepared!
It was Furan (1/2 tablet in a 5 gallons of water) for 1 sick fish.
He couldn't have gotten more than a few licks......will this hurt him??
I've searched the net, and can't find any info
Thanks so much Carol Herard.
<<This medication is classed as not harmful by ingestion/swallowing. I would not be overly concerned. Just keep fresh drinking water available for the cat.
<<Thanks for the question. A Nixon>>

Rabbitfish question, handling  12/15/2007
Hello.
I've got a one-spot Foxface Rabbitfish and we've had it for some time now. It's doing well and growing like crazy.
We bought him in town and nobody told me that the spines could be dangerous.
<Oh yes>
Needless to say, we moved him between 3 tanks now and didn't know. I held him in my hand at one point and even helped him get his gills going in the new tank when the smaller tank he had been raised in crashed. (We had numerous newbie fish disasters throughout the year, but everything is a+ stable now).
I am concerned after finding out that they are venomous, quite by accident, because nobody took the time to tell us, knowing we were newbies.
I've searched the site thoroughly and read the Rabbitfish FAQs, and I see that it mentions that they have a painful sting and are venomous. It does not, however, tell you how venomous they are (from what I saw, but I may have missed it somewhere) or if they are actually fatal, such as the lionfish can be.
<Somewhat less than Pteroines... more than bees... Can be dangerous to folks who have aversion to proteinaceous stings>
I am concerned, needless to say, because he's grown to about six inches long and he's quite the boss of the big tank, with the exception of a few of our tangs, who rule the roost.
Thank you
<I too have hand-handled many Siganids... one just needs to be careful to keep their hands away from the spiny (anterior) portions of their dorsal and anal fins... Bob Fenner>

Snowflake Eel Bite – 11/28/2007
Hi!
<Hello.>
I have read through the posts on snowflake morays. I could not find an answer to my question. I care for a 300 gallon tank at the junior high where I teach science. I have had a snowflake eel in my home aquarium and have never had a problem like this. Today while trying to feed the inhabitants of the tank, at school, the snowflake eel was wildly thrashing in and out of the tank. I had some silversides for him and the lion fish so I grabbed one with me fingers to give him (I know, not recommended ) anyway, he latched onto my finger and would not let go without some coaxing. After he let go I had several small piercings in my finger, and was bleeding. I cleaned the injury with peroxide, but was wondering - do they carry any weird bacteria that could be infectious.
<Several dangerous bacteria have been found in the mouths of moray eels, among them Vibrio and Pseudomonas. If the wound swells, is becoming severely red or you feel insecure about what to do, visit a medical doctor. In addition many (probably all) moray eels possess a weak toxin produced by club shaped cells in their skin, that might be transferred by a bite. Dizziness and tremendous pain are reported symptoms, but the toxin is so far not considered very dangerous (perhaps only to allergic persons).>
I don't know where else to seek an answer.
<The aquarium magazine TFH had an article on moray bites in its September issue. Possibly will be at WWM some day, too.>
Living in Cheyenne, Wyoming doesn't afford me a wealth of expert advise.
<So far I am not aware of anyone, who died due to a moray eel bite, but I am aware of some people, who had to go to the hospital, some because of infection, some because of massive loss of tissue (larger eels). Although most moray eel bites heal without infection and further problems, I’d stop hand feeding. Fingers and silversides are not the healthiest diet anyway. Clam and mussel meat, squid and crustaceans should be used to alter the diet.>
Thanks in advance for any info you can provide.
<Hope that helps. Cheers, Marco.>

Human Lung Disease?  11/26/07
Dear Dr. Fenner,
<Just Bob please... I have no doctorate>
Friday I spent several hours cleaning my sump, pumps, heaters etc. Most of this time was spent hunched over the garage sink with a lot of water vapor rising up into my face. That evening, my lungs felt inflamed. The next day (yesterday) a cough developed and then a high fever followed with all of the usual aches and pains associated. The reason I am writing is because there seems to be a very clear correlation between the cleaning of the sump and the rapid onset of this illness. I read the article posted on your site regarding aquariums and human health, and most of it seemed related to skin infections. Do you know of diseases of the lungs caused by the inhalation of bacteria commonly found in substrate? If so, I would greatly appreciate any references.
Best wishes to you all,
Brad in Basalt
<I do not... but do encourage you to seek out medical attention if you are concerned... I wish you good health. Bob Fenner>

Fire Coral, human hlth.  11/15/07
Just reading your article on fire coral. You mention about getting stung and the treatment, you should also mention that extreme caution should be exercised also, some people like me have extreme allergy to fire coral which can land people like me in hospital, it is not just ouch. I am starting up the salt again soon and I shall do what you say and use gloves at all times. Also I do not know if you mention any other corals that can sting, I know for someone like, I must exercise extreme caution in the hobby now.  By the way I do love your site and your articles, they are very helpful in giving information and giving advice. Cheers Richard South
<Thank you for your input here. Will add/share. Cheers, Bob Fenner... always watching out for Milleporines UW>

Stingray toxicity to humans   10/24/07
Hello
<Hi there>
I was thinking about getting a blue spotted ray and have read on your web site if you are stung that you could have a allergic reaction. How dangerous are they and what percent of the people getting stung have a bad reaction?
<Mmm, folks with allergens to proteinaceous stings might be in trouble... how much, how many? I don't know. Much collateral damage is done physically with such injuries....>
I have read about the blue ring octopus, it's nothing like that is it, or is it more like a lionfish sting.
<More toward the Lion end of the scale>
What kind of ray would you recommend that's not to toxic, if the blue spotted is?
<One of the non-stingray ray species... See WWM, the Net, Scott Michael's popular cartilaginous fishes book re. Rays are not easily kept BTW... as you will find by reading. Bob Fenner>
Thanks Todd

Unshielded DE Metal Halide Bulbs...Danger Will Robinson!!! – 09/10/07
WWM Crew,
<<Rick>>
Your FAQs and dailies have been an invaluable resource. My tank and I thank you for the knowledge.
<<We’re pleased you find the site useful>>
I had two Current SunPod HQI metal halide units (14k w/ 150W, total of 3 original bulbs). When I upgraded to a larger reef tank, neither of the units fit the tank. Rather than purchase a new unit, I removed the contents of each fixture and integrated them into a wooden DIY enclosure.
<<Neat>>
The enclosure utilizes the existing fans found in the original units, as well as an additional and larger fan. The enclosure hangs approximately 13 inches off the tank, with the halides approximately 18 inches off the tank. The tank is adequately covered so as to prevent water splashing onto the bulbs, reflectors or ballast.
<<Mmm, usually little concern with this...better to let the tank “breath” in my opinion>>
The fixture has operated safely for two months now, but I fear the UV/radiation dangers that may be posed by this setup.
<<Oh?>>
My concern is that I have not included any glass/UV shield below the bulbs.
<<Yikes! Yes, this is a “danger”...to you, your livestock, et al!>>
Is this a valid concern?
<<Indeed...please do install UV shields over these double-ended bulbs. Special “UV” glass can be obtained, but simple float glass from the hardware/home store will also afford some protection...or utilize the shields that surely came with the original fixtures>>
Could the bare light exposure be harmful to humans or corals?
<<Not “could be”...”is”... The fact you have the tank “covered” to prevent splash is probably why you haven’t “cooked” your livestock before now...but the potential for damage re, as well as to you and your family, is very high. I have seen “cracked” Mogul-base bulbs do damage to livestock...I can only imagine how hazardous these completely exposed/unshielded DE bulbs must be>>
If so, how can I remedy the situation?
Thank you,
Rick
<<Rick, I can not stress enough the potential danger this unshielded fixture poses to you and your family’s’ health/eyesight. Immediately discontinue use of this fixture until adequate UV shields can be fashioned and fixed in place. Regards, EricR>>

Dangerous Puffers... to human aquarists! SW sel.   7/27/07
Not a question, just a quick story. I was putting an algae sheet on a clip in the tank this morning for my angel and tangs, and my dogface puffer bit the heck outta my finger. Man, those guys have sharp teeth! Beware!!!
Thomas
<Yep, that can happen. If you've ever seen pufferfish feed in the wild, you won't EVER underestimate their power. They can bite off chunks of coral or grind up oysters without any problems at all. It isn't so much the sharpness of their teeth, but the huge jaw muscles. The whole deal with the bug-eyed face and external nostrils you see on puffers is to make space in the head for the jaw musculature. Thanks for writing, Neale.>

Human arms in reef tanks...  7/12/07
Hello,
I was doing some work in the sump of my 300 gallon reef tank (mixed fish inverts) and had to put my whole arm in up to about my elbow. The next day, I noticed several small red bumps on an area of my arm? That I had scraped while it was in the water. It has not spread but it is seriously itchy!!!
<This sounds like an allergic reaction to me. Several types of reef invertebrates produce toxins that irritate skin (just like poison ivy does).>
Some type of fungal or bacterial infection? Any suggestions?
<We certainly can't diagnose you. But this doesn't sound like any of the bacterial infections reef aquarists worry most about.>
I don't have any seahorses but I do have a mixture of snails, crabs, lots of live rock, etc. I am off to the dermatologist tomorrow
<Good idea. You should always see a doctor when you suspect an infection or allergic reaction. And do tell the doctor you have a reef tank.>
but I thought one of you guys might have some insight so I could prevent this from happening again....thx!
<Gloves. There really isn't much else you can do to be sure. There are so many things in reef tanks that can cause reactions like this.
Best,
Sara M.>
Dr Steven R. Cantor

Skin Irritations From Handling Live Rock (Wear Those Gloves!) – 07/12/07
Hi there!
<<Hello!>>
I really appreciate all of your answers, and am currently re-reading Bob's CMA book...wow, what loads of information.
<<Ah yes, and if you like CMA you should really enjoy the bit more updated Reef Invertebrates book which Bob co-conspired with Anthony Calfo>>
Now my question - when I searched, I found info on corals and fish being hurt, and some reference to what I did on a dive magazine's article, but not the exact answer...
<<...?>>
After having hurriedly moved my tank early May (we got new floors, and the tank had to move), I only generally put the rocks back in (I swear, aquascaping can be one of the hardest things about this hobby!)
<<Indeed...tis a matter of “art” as well as function>>
Well, having looked at it now for 2 months, I didn't like the arrangement, and I felt it did not have the nice through-passes I previously had - so on Sunday I carefully redid the aquascaping. No problem with that - except that something on the rocks got me...again!
<<Mmm...is not uncommon...and reason enough to wear some type of protective glove>>
In May, I got the finger tips on my left ring finger and my right pointing finger - very itchy, slight bumps, and after about 10 days, the skin peeled.
<<Yikes!>>
Interestingly, when I went snorkeling in Florida in mid-June, that newly peeled skin would turn white vs. the remaining skin. I thought I had recovered, but I did not yet purchase gloves, not being able to find ones that fit or that I thought would work.
<<Mmm...>>
Well, when I redid the aquascape this Sunday, I got the tips of the thumb through ring finger on my left hand...same as last time. I did not realize it immediately, or I guess an immediate soak in vinegar would have helped, yes? (Dive article solution for majority of stuff you can get while diving).
<<Possibly...but if this is a “Bristle Worm” encounter (would be my first guess), a good wash with soap and water has worked best for me...and then of course some time to allow the “bristles” to dissolve. But, everyone is different and some folks can have quite severe reactions (as with insect stings/bites). And there’s also the possibility you have encountered or contracted something else altogether>>
By Monday morning, my ring finger pad had really swollen (although this time the bumps are actually on the side of the finger) and it has slightly discolored (towards the purple). I have tried the soaking-in-as-hot-water-as-you-can-stand, soak them in Epsom salt water, soak in vinegar, cover with Benadryl (R) cream, cover with an antibiotic cream, taking Benadryl (R) (liquid children's version) - but nothing seems to really help with the periods of itching.
<<If this has continued for more than a couple days I would suggest seeing a Doctor/Dermatologist...being sure to explain/making them understand just how you came by the affliction>>
Just a few minutes ago my thumb had an itch attack - and then it went away again a few minutes after I applied antibiotic cream - but the itching was almost painful in its
intensity, so I am curious what is going on. Any ideas what got me?
<<I can only speculate, but my first inclination is you have been “stabbed” by Bristle Worms. These beneficial detritivores are in and around the live rock you have been handling and the slightest touch/brush will leave the ever so sharp (and possibly toxic) bristles embedded in your skin. These bristles will break off leaving bits that irritate and itch...but in most cases will dissolve away within a few days. There’s also a myriad of other stinging organisms that could have caused this, depending on your sensitivity re...or this could be a secondary infection due to broken/scraped skin exposed to the water. Do have a read here for some more in-depth info: http://www.wetwebmedia.com/Wound.htm >>
Any suggestions for reducing the itching?
<<I find using a topical ointment containing Cortisone to be helpful>>
I have read about toxicity of marine life, but as far as I know, I don't have fire corals - in fact, I was simply touching my rocks, so what is on the rocks that is so toxic?
<<Many things...with exposure to Bristle Worms being very common>>
I realize it is worse this time, so I am working very hard on getting gloves that fit to prevent this in the future - I did learn my lesson, albeit the painful way.
<<Mmm, yes...have heard of some folks developing a more severe reaction with every encounter...so far I have been lucky>>
Thanks again for any inputs you have, and maybe this will help someone else in the future as well.
Kerstin DeRolf
<<I’m sure it will. Do get your wounds looked at/tended if the irritation persists...and get those gloves! Eric Russell>>

Re: Skin Irritations From Handling Live Rock (Wear Those Gloves!) – 07/13/07
Hi again!
<<Hello Kerstin!>>
Thanks for your response –
<<My pleasure>>
I do have bristle worms (while my wrasse seems to have reduced the number, I am not silly enough to believe that they are completely gone),
<<And not necessarily a desirable objective...are quite efficient/beneficial (and largely misunderstood, I think) detritivores>>
but also wonder is something may be growing on some of my rocks that could have done it as well.
<<Certainly, yes...this also is a possibility. Or simply a secondary infection of abraded flesh from exposure to the very concentrated soup of microbes in the system>>
I am glad (?) to hear that this is not uncommon, and yes, I think I am more sensitive to it just from having done a similar thing 2 months ago.
<<Common yes, but without being an alarmist I also don’t want to downplay the “potential” for serious consequences here>>
I did actually read this article on Tuesday, before I wrote to you - and some of the suggestions are the same as in the Dive article I ran across.
<<Ah, I see>>
I think one of my biggest problems is that I did not realize it on Sunday, shortly after it happened, and so waited a long time before really doing any treatments. I stymied my vet (specialized in dermatology, also studied fisheries, albeit freshwater) with it - when I showed my fingers to him this morning, at this point his solution is to do hot super-saturated salt water or Epson Salt soaks, twice a day for 20-30 minutes, water as hot as I can stand it.
<<If this complaint is still bothering/worsening I urge you to see a “people” doctor (no “slight” intended against your friend)>>
I do have the Reef Invertebrates book - like it lots too, has been useful in many ways.
<<Indeed>>
Should get the next edition of Anthony's Coral Propagation book soon, will also be interesting reading, I feel.
<<Very much in agreement>>
Right now I am trying to get Latin/technical names for my corals, many of which I admit I bought based on looks more than anything...not useful when I want to discuss them with anyone.
<<Mmm...also not useful when trying to determine care level/needs/overall suitability for captive keeping...all of which should be done “before” purchase. Eric Borneman’s book “Aquarium Corals” may prove helpful to you...as should this site: http://www2.aims.gov.au/coralsearch/coralsearch.php >>
Thanks again for all your help.
<<Any time>>
I really enjoy reading everything on your website - soooo much information, people coming at it from all various aspects.
<<Indeed...quite the collaborative effort>>
Kerstin:-)
<<Be chatting. EricR>>
P.S. Attached is the picture of my tank after the rearrangement that massacred my fingers - a 29-gallon that I know has lots of corals!
<<Ah yes...looks quite “busy” in there>>
I am working on getting a new skimmer - Aqua-C Remora HOT instead of
the SeaClone I now have.
<<Will be a huge improvement>>
I feel like my tank now has a heavy enough load that it needs more than the periodic skimming
<<Agreed>>
(Bob called it "a natural method" in one FAQ)
<<Indeed...do try a Google search on Lee Chin Eng and the “Natural Method”...you think your tank looks heavily stocked now....>>
where I only run the skimmer as an actual skimmer several times a month, and otherwise depend on the LR and LS to do much of the filtering.
<<Well past that point...in my opinion>>
I think most everyone will be happier
<<Oh yes!...have you heard of/researched the term “Allelopathy?”>>
- and hopefully soon I will upgrade the tank size.
<<Always exciting. Eric Russell>>

Is Metal Halide Lighting Harmful To My Health? - 06/27/07
Hi!!!
<<Hello!!!>>
Hope you can answer my question today.
<<Let's see then...>>
Is being exposed to metal halide lighting bad?
<<Mmm, wish I knew what your definition of "exposed" was here...but generally speaking keeping "direct" exposure to a minimum is a good practice>>
Is there any negative effects on health?
<<I would think any health risks would be very similar to those associated with too much exposure to the Sun>>
Anything I should be worried about?
<<Do take steps to shield your eyes/your families eyes from direct exposure by using proper lamp housings/fixtures and avoid looking directly at a burning bulb...the occasional/accidental glance is not going to permanently "blind" you in my experience, but it will "dazzle" you a bit...again, much like looking at the Sun. I don't think you need to be "afraid" of metal halide lighting, but it is a very intense light source that produces varying amounts of Ultra-Violet radiation that does indeed require your respect>>
Thank you!
<<Happy to proffer my non-medical opinion...I hope it helps. Eric Russell>>

Hebrew Cone (Conus ebraeus), Poisonous? Yes!  Degree of toxicity... ?   5/13/07
Hello crew,
<Hi Jana, Mich here.>
I am trying to find on the Internet how poisonous the Conus ebraeus is?
<Well it does kill it's prey, primarily eunicid and Nereid polychaete worms, by injecting them with conotoxin, a potent neurotoxin that disturbs the ion channels involved in neuromuscular transmission, typically resulting in paralysis.>  
I found information on other cone shells but not on this particular one.
<Yes, I too am having difficulty finding anything specific to this particular species.  There are more than 600 members of the Conidae family and only 30 documented cases of envenomations by Conus in humans, some resulting in death.  The most toxic is reported to be Conus geographus, though C textile, and C marmoreus are also associated with an increased of mortality.  I have been unable to find any reports describing the degree of toxicity of the conotoxin associated with C. ebraeus, but it is certainly something to take seriously and the effect of the conotoxin would likely vary between individuals.  Also worth noting is current research on members of this family for the treatment of pain and conditions such as Parkinson's.>
Is it found in Australia and how poisonous is it.
<The distribution of Conus ebraeus occurs in the Indo-west Pacific and Eastern Australia as far south as Sydney.
Many thanks, kind regards, Jana.
<You're welcome.  Mich>

Re: Lugol's Dip and Gorgonians, Pete, will you take a look at, refer? & bacteria f', human dis.   – 4/10/07
<Yowsa Pete! Thanks as usual for this dissertation! BobF>
Dear Mark:
Bob forwarded your email to me and asked me to lend a hand with your dilemma.  It's very difficult to say what may have caused the demise of  your H. kuda but I would be happy to share my thoughts on the matter with you  for whatever it's worth, sir.
Like all fish, seahorses do occasionally develop various granulomas, malignant neoplasms, tumors and fibrosarcomas associated with certain diseases  or the aging process, but these primarily affect internal organs.   Furthermore, such growths are not characteristic of vibriosis and, judging from  the symptoms you described -- or lack thereof -- it seems unlikely that a Vibrio infection was involved in this case.
I am more concerned about the possibility that the tumor may have been a granuloma symptomatic of a Mycobacterial infection.  Granuloma disease is  caused by gram positive, acid-fast bacteria from either the genus Mycobacteria  or the closely related genus Nocardia invading the tissue and internal organs and organ systems. Both of these bacteria can affect the skin as well as the internal organs, causing nodules and granuloma. And both Mycobacteria and Nocardia can be transmitted to man, causing a localized, unsightly skin rash  after entering through a cut or break in the skin.
Here is an excerpt from my new book (Complete Guide to the Greater  Seahorses in the Aquarium, TFH Publications, unpublished) that discusses mycobacteriosis in more detail, Mark.  It may help give you a better idea  whether or not the tumor you noticed could have been associated with granuloma  disease:
MYCOBACTERIOSIS, A.K.A. PISCINE TUBERCULOSIS
Mycobacteriosis is also known by the following synonyms: fish tuberculosis, piscine tuberculosis, granuloma disease, swimming pool granuloma, fish tank granuloma, and acid-fast disease (Aukes, 2004; Leddo, 2002a). Like all fishes, seahorses are susceptible to Mycobacteriosis. It is not uncommon in wild-caught  seahorses obtained from pet stores and is the second most commonly seen  bacterial infection of syngnathids at large public aquaria after Vibriosis (Bull  and Mitchell, 2002, p20).
Cause:
Fish tuberculosis is caused by pathogenic Mycobacteria, of which two different species are the primary culprits: Mycobacterium marinum and  Mycobacterium fortuitum (Giwojna, Sep. 2003). Unlike most bacteria the plague  fish, these Mycobacteria are gram-positive, and take the form of pleomorphic  rods that are acid-fast and nonmotile (Aukes, 2004). When cultured on solid  media, they form cream-colored to yellowish colonies (Aukes, 2004).
Mycobacteriosis is worldwide in distribution (Giwojna, Sep. 2003). All fish species are considered susceptible to it (Aukes, 2004). Although this disease can in fact infect almost all fish, certain species are more vulnerable than others (Giwojna, Sep. 2003). The most susceptible species are freshwater tropicals such as black mollies, all gouramis, Neons and other tetras, all labyrinth air breathers, and most species of the Carp family (goldfish and koi, for example), Aukes, 2004.
Mycobacteria are ubiquitous and waterborne, and the aquatic environment is considered the disease reservoir for fish tuberculosis (Aukes, 2004).  
Mycobacterium marinum has been cultured throughout the world from swimming pools, beaches, natural streams, estuaries, lakes, tropical fish tanks, city tap  water and well water (Aukes, 2004; Leddo, 2002a). Human epidemics of  granulomatous skin disease have occurred from swimming in infected water, and in  fact, this mode of human infection is far more common than infection from  exposure to infected fish tanks (Aukes, 2004; Giwojna, Sep. 2003).
Clinical Signs:
There is a very severe or peracute form of this disease, in which fish can simply be found dead without showing any telltale signs or symptoms (Bull and Mitchell, 2002, p20), but that is quite rare. In my experience, Mycobacteriosis  is a chronic disease that progresses quite slowly in aquarium fishes (Giwojna,  Sep. 2003). It may take years for an infected fish to develop any symptoms of  apparent illness and much longer before it becomes fatal (Aukes, 2004).
The  glacial progression of the disease makes it difficult to diagnose. Some early  signs to look out for include lethargy, fin loss, emaciation, skin inflammation  and ulceration, edema, Popeye, and peritonitis (Aukes, 2004). There may be  superficial skin lesions that take the form of small subdermal lumps or pus-filled nodules of granulation tissue (Bull and Mitchell, 2002, p21).
These  are simply the outward manifestations of a systemic infection that may already  involve many of the major internal organs (Bull and Mitchell, 2002, p21). In  later stages, nodules may develop in muscles or skeletal structure and deform  the fish. (Giwojna, Sep. 2003).
As difficult as slow-moving TB may be to diagnose while the infected fish  is alive, once the victim expires, postmortem examination will reveal clear, unmistakable signs of Mycobacteriosis (Giwojna, Sep. 2003). The telltale granulomas will appear as gray or white nodules in the liver, kidney, heart  and/or spleen (Aukes, 2004). There is often black, necrotic tissue eating away  at the internal organs, and there may also be skeletal deformities. Diagnosis is then confirmed by the presence of acid fast bacteria in tissue sections (Giwojna, Sep. 2003).
Treatment and Control:
There is no practical method for treating mycobacteriosis or granuloma disease at the hobbyist level.  As discussed below, good aquarium  management can prevent Mycobacteria/Nocardia from becoming problematic.   Prevention is the watchword for this condition.
Transmission:
The bacteria can be transmitted through the water from open ulcers, through contaminated food (including live foods such as shrimp or molly fry), via feces  of infected fish, or through the consumption of infected, dead or dying fish in  the tank (although the latter does not apply to seahorses), Aukes, 2004.
Contributing factors:
This disease is not highly contagious and does not seem to spread from fish to fish readily (Aukes, 2004). However, fish TB it is often associated with poorly kept or dirty tanks with poor water quality (Aukes, 2004). Chronic stress  from factors such as overcrowding, malnutrition, or aggressive tankmates often  plays a role as well (Giwojna, Sep. 2003).
Mycobacterium, the causative organism, is believed to be ubiquitously present, making it very difficult to eliminate it entirely. However, if good aquarium maintenance and management is followed, including vacuuming of the  gravel along with good filtration and regular water changes, combined with a nutritious diet and the addition of an enrichment product rich in vitamins, the problem can be minimized and eliminated as a cause of mortality (Aukes, 2004).  
Any dead fish should quickly be removed and disposed of properly. Diseased live fish should be isolated and treated in a hospital tank (Giwojna, Sep. 2003).
Transmission to Man:
The seahorse keeper should be aware that piscine tuberculosis is one of the few forms of fish disease that is communicable to humans (Leddo, 2002a). This transmission usually manifests itself as an unsightly skin rash involving one or  more granulomas on the arms of the fish-keeper (Leddo, 2002a). In severe cases,  these nodules of inflamed tissue can become large and disfiguring.
They can  spread and be very difficult to eliminate. The granulomas often take some 2-4  weeks after exposure before manifesting themselves, so the individual is  frequently unaware of how he or she contracted them and the condition very often  goes undiagnosed (Giwojna, Sep. 2003). The Mycobacteria that cause the disease  typically gain entry through a break in the skin such as a cut, scrape, or  abrasion on the hand or arm of the aquarist (Leddo, 2002a). Although unsightly,  the granulomas themselves are not a serious problem and are almost always  localized and most certainly curable in healthy individuals. But for those of us  whose immune systems are compromised by AIDS, kidney disease, diabetes, liver  dysfunction, chemotherapy or the like, the infection can sometimes become  systemic or, on rare occasions, even life threatening (Giwojna, Sep. 2003).
Awareness is the appropriate response to the risk posed by fish tuberculosis. The seahorse keeper should be aware of the remote possibility of  being exposed to Mycobacteria via his aquarium, and take appropriate  precautions, but there is certainly no need to be overly concerned (Giwojna,  Sep. 2003).
The aquarist should merely remain aware of Mycobacteria and follow the  usual sensible precautions. Nets, aquarium accessories and equipment, and any other items that may come in contact with the fish should be sterilized between uses to prevent cross-contamination (Giwojna, Sep. 2003). Avoid mouth-siphoning of the water in a Myco-positive tank (use a hand pump instead).   
Mycobacterium cannot penetrate intact skin -- it only causes infection after  entering through open wounds or source, so make full use of aquarium gloves and  don't place your hands or arms in the aquarium if you have any cuts or scrapes (Giwojna, Sep. 2003). Handle sick fish carefully, dispose of deceased specimens properly, and scrub up afterwards. Do NOT dispose of dead fish by flushing them down the toilet, as this is a prime way to spread disease. Place the fish carcass in a plastic bag or wrap it in some foil and dispose of it with the solid waste of the household. And don't feed dying fish to larger carnivorous fish, since this an excellent way to spread infection (Giwojna, Sep. 2003).
One thing hobbyists who are worried about fish TB can do to allay their concerns is to get their seahorses and live foods (crustaceans such as shrimp  are known vectors for Mycobacteriosis) from a High Health facility such as Ocean Rider rather than from their local fish store (Giwojna, Sep. 2003). Seahorses at  OR are routinely screened for pathogens and parasites by independent examiners  from an outside agency (DVMs with the Department of Agriculture), and I know for  a fact that Mycobacteriosis is one of the diseases they specifically check for  (Giwojna, Sep. 2003). Thus far, multi-organ histopathology has found no  granulomas and tissue sections have revealed no acid-fast bacteria -- conclusive  proof that Ocean Riders are free of Mycobacteria. <Close quote>
That's the rundown on mycobacteriosis or granuloma disease, Mark.
The very similar Nocardia is a gram positive, acid-fast, filamentous bacteria and is even more insidious than Myco. Nocardia is closely related to  the Mycobacteria that cause piscine TB or granuloma disease and, like  Mycobacteria, it can affect the skin as well as the internal organs, causing  nodules, granulomas and pyogranulatomous cysts. And like Mycobacteria, Nocardia  can be transmitted to man, so be sure to take appropriate precautions if you  suspect granuloma disease may have caused the death of your H. kuda.
Here is some information from Paul Anderson explaining how professional aquarists typically deal with Mycobacterium/Nocardia:
Fellow Seahorse Enthusiasts:
Mycobacterium is a genus of bacteria that are ubiquitous in almost all environments. Mycobacterium infections occur in many (if not all) vertebrate  taxa (e.g., mammals, birds, fish, etc.). Some studies that have looked at prevalence of infection of Mycobacterium in wild animals have often found that a small percentage of wild animals are infected, even without clinical signs.
The most common Mycobacterium species found in seahorses are M. marinum, M. chelonae, and M. fortuitum. There is currently no cure for mycobacterium infections in fish. The options available are to 1) depopulate and disinfect the system, or 2) maintain the fish but prevent cross-contamination by observing strict biosecurity protocols. The second option is often chosen by public aquaria with long-standing displays, when aquaculture/production of the infected  fish is not an issue.
Many mycobacterium spp. can cause disease in humans, especially if the species is a rapidly growing one and/or if the person is immunocompromised. Of  the three species mentioned above, M. marinum is a slow grower, and grows at 25 degrees Celsius incubation, but not at 37 degrees Celsius. The other two are rapid-growing species and grow at both temperatures of incubation. The significance of 37 degrees is that it is human body temperature. While most infections of otherwise healthy people are limited to lesions on the extremities (even with infection by a rapid-grower), there is a greater risk of the rapid-growers to cause systemic disease (especially in immunocompromised  people).
In a Myco-positive tank, the best option is not to come in contact with water or fish; wear gloves (sleeved gloves if necessary). Avoid mouth siphoning (use a hand pump). Having said that, in an aquarium situation mycobacterium only  causes infection if it enters a wound; it cannot penetrate intact skin.  
Effective disinfectants against mycobacterium include spraying with 70% Ethanol and allowing the equipment to air-dry, and bleach baths (I use 50ppm bleach baths with a minimum contact time of one hour, this has been reported to be effective against M. marinum) followed by sodium thiosulfate neutralization baths. Ultraviolet light sterilization is also recommended in Myco-positive systems. If you've got Myco-positive tanks among other systems, common sense suggests performing husbandry on these systems last in your rounds.
A note on ethanol: I have found in my experience that seahorses are very sensitive to ethanol, so I advise being very cautious to avoid overspray into tanks (while we're€™re on the topic, has anybody else observed this?)
Check out the following for more information about mycobacterium infections in fish/aquaria:
<_http://edis.ifas.ufl.edu/VM055_ (http://edis.ifas.ufl.edu/VM055) >
<_http://www.mdsg.umd.edu/Extension/finfish/FF9.html_
(http://www.mdsg.umd.edu/Extension/finfish/FF9.html) >
Mainous, M.E., and S.A. Smith. 2005. Efficacy of common disinfectants against Mycobacterium marinum. Journal of Aquatic Animal Health 17:  284-288.
Paul Anderson
Ph.D. Candidate
Department of Fisheries and Aquatic  Sciences
University of Florida
That's the situation when Mycobacteria is confirmed in an aquarium,  Mark.
As long as you observe the proper precautions and practice good  aquarium management, it's a problem the aquarist can sometimes live  with...  
Nocardia is a different matter.  When Nocardia is confirmed in an  aquarium, the only real recourse is to break down the entire aquarium, discard  the live rock, substrate, and invertebrates, sterilize everything, and start  over from scratch.  The problem is that Nocardia is saprophytic -- it  doesn't require a host to survive and it will persist in your system  indefinitely. These bacteria live off any kind of dead or decaying organic  matter; in nature they are commonly found in soil and wastewater -- in your  tank, Mark, they are no doubt entrenched in your substrate, live rock, filters,  everything -- where they act as a disease reservoir, ready to infect any new  fish and invertebrates (or careless humans) they encounter when the opportunity  presents itself.
The risk of cross-contamination of your other tanks and specimens is great, compounded by the fact that human health (primarily yours, Mark) is also at risk  from this organism.  If your H. kuda was infected with Nocardia, then everything in your 25-gallon aquarium has been exposed to these bacteria and is potentially a source of infection. Leading the tank lay fallow indefinitely will  not help with Nocardia whatsoever.  If Nocardia killed your kuda, you must consider all the equipment, decor and specimens in the tank to be contaminated,  Mark -- treat them like you would toxic waste or any other biohazard.
Even your  invertebrates are a risk. Your coral, macroalgae, etc,. are all sources of  organic matter, and can therefore harbor Nocardia and carry the infection.
Do NOT disperse your live rock, substratum, Gorgonia and soft corals, macroalgae, equipment or accessories from the 25-gallon tank to your other aquaria, Mark, or you will be inoculating them with Nocardia and spreading the infection to all your tanks! And you must be extremely careful to avoid accidentally cross-contaminating your other tanks from your 25 gallon aquarium.  Any nets, hydrometers, or other equipment used in your 25-gallon aquarium should  be sterilized after every use and not placed into or used in any other tanks.
Avoid working in infected aquarium with your bare hands, scrub/disinfect your hands and arms thoroughly after working on the tank, and do not place your hands in the 25-gallon tank and then place your hands in another aquarium. These bacteria can even be transferred from one aquarium to another by splashing water  droplets or as an aerosol via the mist generated from a protein skimmer or an  airstone. Be careful!
That is what I typically advise hobbyists when Nocardia has been confirmed in their aquaria, Mark.  I hesitate to recommend such drastic measures when Nocardia or Mycobacterium have not been confirmed.  And the tumor that you described is not typical of the pyogranulatomous cysts that characterize Nocardia.  They most often present as greyish-white pimple like lesions on  the skin.  
They are often motile when manipulated and may release a cheesy  exudate when compressed.  That does not sound like the hard mass you  detected beneath the skin near the vent of the H. kuda.
So you're going to need to use your own judgment, Mark.  To be 100%  safe, you could discard the contents of your 25-gallon aquarium, sterilize everything, and start over from scratch.  Or you could dip the live rock,  Gorgonia, and corals with Lugol's solution as a precaution and then trust to  good aquarium management to keep the seahorses in your 40-gallon aquarium  healthy and happy.  Since Mycobacteria and Vibrio bacteria are virtually  ubiquitous, and normally only become problematic when the seahorses have been  stressed and their immune systems have been impaired, I might be inclined to  take the latter course in your case.  If you can provide your seahorses  with optimal water quality, a nutritious diet, and they stress-free environment,  the chances are good that your livestock will not be affected by granuloma  disease or vibriosis.  
Starting out with seahorses from a high-health  aquaculture facility that you obtain directly from the breeder will further  increase your chances for success.  As an added precaution, you may also  want to consider installing an ultraviolet sterilizer on your 40-gallon seahorse  tank after it has cycled completely and the biofiltration is  well-established.
Best of luck with your new seahorse tank no matter how you decide to proceed, Mark!
Respectfully,
Pete Giwojna, Ocean Rider Tech-Support

Re: Lugol's Dip and Gorgonians, Pete, will you take a look at, refer?  – 4/10/07
Dear Bob:
<Pete!>
I'm always happy to help when I can, sir.
<And you do a fine job of it, I assure you>
When I receive inquiries from aquarists regarding Mycobacteria/Nocardia, I feel it is very important to provide them with as much information as possible because of the possibility of human transmission and because they may be confronted with the decision as to whether or not it's necessary to depopulate their aquarium, sterilize everything, and start over from scratch.  So I  make it a point to try to arm them with all the facts they need to make an informed decision in that regard.
<Yes... and one of the principal reasons for my encouraging the publication of your book, your articles (as well as others... including my own!) to get "complete answers" to folks... in a speedily manner>
Hopefully, once we get my new book on seahorses published and into the  hands of the hobbyists, there won't be a need for us to devote so much time discussing these issues on the forums.
<Heeeeee! You'll see...>
Happy Trails!
Pete Giwojna
<And to you, Bob Fenner, out in HI, at times visiting with Carol and Craig and their (now four year old!!!) boys, Dylan and Cooper>