FAQs on Thiaminase and Aquatic Nutrition
Related Articles: Feeding "Feeder" Goldfish by Bob
Fenner, The Feeder Fish Debate: Are
They Essential, Cruel, Or Dangerous? by Neale
Monks, Thiaminase
and It's Role In Predatory Pet-fish (& Other Piscivores)
Nutrition, by Marco Lichtenberger, Culturing Food
Organisms,
Related FAQs:
Nutritional
Diseases,
Brine
Shrimp, Algae as Food,
Vitamins, Feeding Lionfishes, Frozen Foods, Culturing Food Organisms,
|
|
Thiamine deficiency in large fish /Marco
10/31/17
Having a problem with a client who has number of large tanks containing
predatory fish. Have lost a number of large fresh water fish such as
peacock bass, Arowana, and tiger shovelnose catfish, all fish were long
term inhabitants two+ years. Symptoms are bloating, lost of balance and
stoppage of eating.
<Especially bloating is not a typical symptom of a thiamine deficiency
syndrome (see
http://www.wetwebmedia.com/ca/volume_6/volume_6_1/thiaminase.htm ).
Maybe something else is the culprit here.>
Within a week or two the fish perish. After doing research I suspected
thiaminase poisoning, fish were being fed strictly smelt. I have since
changed food to a silver side that does not contain thiaminase and some
Hikari Pellets.
<Keep it as varied as possible.>
This week there is a saltwater Queen Trigger that’s showing the same
symptoms is there a good way to get Thiamine (Vitamin B1) into the fish?
Injectable? In a bath? Do realize this fish is about 18-20” and weighs
4-5pounds.
<Injections (by a vet) are possible but the usual way is to add it to
food. Most vitamin substitutes for fishes contain sufficient amounts of
thiamine.>
Thanks in advance for any help. Jeff
<Good luck. Marco.>
Thiamine deficiency in large fish /Neale
11/1/17
Having a problem with a client who has number of large tanks containing
predatory fish. Have lost a number of large fresh water fish such as
peacock bass, Arowana, and tiger shovelnose catfish, all fish were long
term inhabitants two+ years. Symptoms are bloating, lost of balance and
stoppage of eating. Within a week or two the fish perish. After doing
research I suspected thiaminase poisoning, fish were being fed strictly
smelt.
<A single food item, regardless of what it is, would easily explain the
symptoms you describe; i.e., some sort of vitamin or mineral deficiency.
Whether thiamine (vitamin B1) deficiency or some other, hard to say; but
I do believe your analysis here is a good bet.>
I have since changed food to a silver side that does not contain
thiaminase and some Hikari Pellets.
<These latter are excellent, among the best foods in the business, and a
combination of them (for all-round nutrient balance) and frozen food (to
keep the fish interested) is the way to go with all predatory fish in my
opinion. Even better if you can stuff some pellets inside the
silversides, especially plant-based foods such as Spirulina. Do remember
that carnivores consume a lot of fresh greens -- albeit via the
intestines of their prey!>
This week there is a saltwater Queen Trigger that’s showing the same
symptoms is there a good way to get Thiamine ( Vitamin B1) into the
fish?
<There are marine aquarium vitamin supplements, such as those from
Selcon, Kent Marine, Waterlife and others. Some, like the Kent-C
product, are added to the water (bear in mind fish drink continually, so
this is more effective than it sounds) while others, like the Selcon
vitamins, are used to "soak" freeze-dried foods before use. Basically,
follow the instructions on the packaging. Short-term,
stuffing/gut-loading frozen or live food, such as cockles or river
shrimp, with Spirulina flake is a good way to quickly get a bunch of
vitamins into a fish. Because many vitamins, including B1, are water
soluble, the body can't store them, so you can't get more into an animal
faster than it can assimilate and use them. So while injections do exist
(a vet will have to do these) they have a short-term effect and are more
about crisis management than recovery. For a fish that's basically fine,
if a bit off-colour, a day-to-day offering of vitamin-enriched food
should gradually turn things around. Fresh greens always help, though
Triggers aren't particularly herbivorous beyond a bit of calcareous
algae, so you might need to shove something like Sushi Nori or Spirulina
into a cockle or mussel and hope he takes them that way. Vitamin
deficiencies aren't normally fatal if caught early enough, though
deformities caused by them may be.>
Injectable? In a bath? Do realize this fish is about 18-20” and weighs
4-5 pounds.
<Vitamin-enriched food as described above should do the trick.>
Thanks in advance for any help.
Jeff
<Most welcome. Have asked Bob to chime in if anything missed. Cheers,
Neale.>
Avoiding Thiaminase 9/7/17
Hello crew,
I read the article on Thiaminase and I found it very informative. I was
left with a question, what am I supposed to feed my porcupine puffer? I
see that there are some non-Thiaminase fish offerings, but puffers do
not eat fish.
<Mmm; assuredly they do. Have seen several species of puffers consume
fish in the wild and captivity>
It caused fatty liver disease over time.
<Do you have reference/s for this assertion? Your intuition,
experience?>
It seems that everything I feed him is high in Thiaminase. Squid,
scallops, clam, mussel, oyster, shrimp is always in the mix. I do add
Boyd's Vita Chem to the food. Is this enough to counteract the effects
of the Thiaminase.
<To some extent; yes. B vitamins can be added to foods, water...>
I used to use Selcon, but the Boyd's seems to be a more complete multi
vitamin.
Thanks,
Jason
<I'd add in some whole (small) fishes or bits of fillet in this mix of
invertebrate fare. Bob Fenner>
Re: Avoiding Thiaminase 9/8/17
Thank you for the response.
<Glad that we're sharing Jason>
This is a quote from an article by Kylyssa Shay. Do you think that this
is not true in all cases? Maybe puffers cannot have fish as their main
diet, but can have it as part of a diet?
https://pethelpful.com/fish-aquariums/porcupine_puffer_basics
"Balloonfish are not piscivores. That means that, in nature, they don't
eat fish. Do not feed fish, live or dead, to them. Feeding fish to pork
puffers may cause something called fatty liver disease, a usually fatal
ailment.
Not only that but the nutrient balance found in fish is very different
from that found in mollusks and crustaceans, their natural prey. Feeding
fish, especially live feeder fish, to your porcupine puffer can also
unnaturally
accustom him to eating fish, making him a danger to future tank mates.
Carefully read the ingredients of any prepared fish foods you give your
pet.
Choose those with invertebrates such as shrimp, krill, squid, clams, or
mussels listed as their first ingredient. Avoid all prepared fish foods
with any type of grain or fish meal listed first in the ingredients."
Jason
<Mmm; well... will have to look further for input; but though I agree
that Diodontids are principal feeders on hard-shelled invertebrates in
the wild; have seen them eat Seastars, fishes... BobF>
Re: Avoiding Thiaminase 9/15/17
This is a snap of the ingredients of the main food I feed all my fish.
There is some whitefish and Pollock in it which is on the no-thiaminase list.
Maybe this food is better than I thought??
<I suspect you'll be fine here w/ this mix; as long as it isn't overfed, and you
supplement with B vitamins. Bob Fenner>
Jason
|
|
Thiaminase 1/4/12
Hello and Happy New
Year to the Wet Web Crew,
<Hi Richard and a happy new year to you, too.>
I've been doing research on Thiaminase in fish as it
relates to feeder fish and in so doing have contacted a
number of fish nutritionist and the author of a study on
Thiaminase in Lake Trout. Here are some
interesting facts:
1) Amazingly, there are no known examples of warm water
species of fish or reptiles suffering from thiamin
deficiency when consuming live prey. No references
period.
<No scientific references maybe, since there is little
interest in this topic so far. There is also no
scientific study showing that consuming live, Thiaminase
containing food has no impact on warm water fishes. What
we have is empirical evidence from decades of keeping
predatory fishes (including some mostly fed with
feeders, although is is done not that often and with a
lot of species), which can be linked to malnutrition and
at least symptoms similar of those suffering from a lack
of thiamin, just have a look on the disease FAQs of the
common predatory fishes at WWM.>
Thiaminase became a concern after it was discovered that
fish in the Great Lakes and Baltic suffered low
fertility rates as a result of consuming non-native
species of Thiaminase containing fish. This
phenomena is strictly limited to these studies and it is
postulated that it is temperature related and associated
with the amount of time prey is in the stomach prior to
digestion. Thiamin is released upon destruction of
tissue and will begin to degrade thiamin in the gut. In
warm-water species enough thiamin is absorbed in the gut
prior to its deactivation to make it a non-factor.
<If this was that simple no animal with a fast
metabolism would suffer from eating Thiaminase rich
food, but they do, even mammals with much faster
metabolisms than warm water fishes.>
Fish that contain Thiaminase are often actually rich
sources of B1. It is the digestion rate that effects
uptake of B1 in lake trout which is why you see higher
thiamin content in Lake Trout in the summer months even
though the Thiaminase levels in alewives are at their
highest.
2) Feeding an exclusive diet of frozen fish that contain Thiaminase over
many months will be the surest way to produce
B1deficiency.
<That's actually what can be observed most often in the
hobby.>
This has been demonstrated with mink, foxes and
alligators. All of which were fed frozen
Thiaminase containing fish and after a number of months
developed beriberi. However, if someone had to
feed frozen, simply using a varied diet of multiple
species of fish that included non-Thiaminase species
would prevent malnutrition.
<Just what is recommended in the WWM article.>
The mink and fox farmers learned to cook their fish soon
after landing to neutralize Thiaminase. Ice
crystals rupture cell structures that then releases
Thiaminase into the tissue. Even in a freezer
Thiaminase will deactivate thiamin rather quickly.
3) Thiaminase does not cross the blood barrier but remains in the gut.
Some species of fish appear to sequester Thiaminase in special cell
vacuoles, but with predatory fish the Thiaminase does
not cross the blood barrier and remains in the gut.
Thiaminase passes out of the gut with the undigested
food. Thiaminase does not build up in the system
and as long as a varied diet is followed that includes
non-Thiaminase containing species fed at different
times, even cold-water species will thrive. There is no
science or evidence that feeding live has ever caused
thiamin deficiency in warm-water species. The fish
nutritionist that I have contacted, the author of the
Lake Trout study and all the literature concur on this
point. Only feeding an exclusive diet of frozen
Thiaminase containing fish will cause vitamin B1
deficiency in
warm-water species. And, only if continued for prolonged
periods of time.
Your discussion on Thiaminase is extensive and mostly
accurate, but I do not believe that it takes these
subtleties into mind, which leads to consequential
conclusions on the part of the reader.
<We'll add your opinion to the FAQ.>
It is important to emphasize that this is a cold-water
disease as defined by the literature, and that there is
a monumental difference between feeding live vs. frozen
in regards to nutritional quality in many respects.
<See my opinion above.>
Thank you for your time.
<Welcome. Marco.>
Sincerely, Richard Rombold
Re: Thiaminase 1/5/12
Let me say first, you guys rock that you take this issue
so seriously.
<Thanks for your kind words. My intention was seeing
predatory aquarium fish suffering from symptoms known
from thiamin deficiency for many years.
Those belong to two groups: A big group being fed frozen
food (mostly one type of fish or shrimp or bivalve) and
a small group being fed goldfish and minnow feeders. I
am not aware of apparently Thiaminase related problems
with feeder mollies (as noted in the article), though.>
Let me try to review this article and put some thought
into your good points and get back to you in a couple of
days.
<OK.>
I greatly suspect that the Barramundi were not fed live
fish.
<That's probably right. My point in sending this article
citation was mostly to show a scientific study, which in
addition to empirical evidence, states if Thiaminase can
be a problem for tropical fish, since you suggested
their faster metabolism and faster uptake of thiamin
would prevent them from the consequences. Based on the
cited article and empirical evidence I cannot confirm
the idea of a fast metabolism making Thiaminase
completely harmless in tropical fishes, and it seems it
cannot be confirmed for reptiles and mammals. The
digestion period of small to medium sized morays for
example is between 24-72 hours depending on the food
composition and the activity and size of the fish (much
slower than in a mink, which can show Thiaminase related
diseases). Inside a tropical fish or warm blooded animal
the breakdown of thiamin by Thiaminase can be faster
than inside a cold water fish.
With regard to feeding live or fresh fish, I do concur
that the relation of thiamin to Thiaminase is better
than on frozen food (I stated this in the article).
However, I would not claim it to be safe. There is no
study I am aware of analyzing the use of e.g. minnows as
feeders and thiamin supply. I can only offer empirical
hobby evidence of fish being fed goldfish and minnows
leading to possibly/probably Thiaminase related diseases
with the known results. I did not observe this with
homebred mollies as feeders. My resulting measures and
recommendations from working on the Thiaminase topic
were simple: feed a varied diet, prefer Thiaminase poor
food when possible and add vitamins to frozen food. I
generally do not recommend feeder fish and rarely used
them myself. Neale has a good article about the feeder
fish topic:
http://www.wetwebmedia.com/fwsubwebindex/fdgfdrartneale.htm
.
I remember another study on tropical groupers, which
came to the conclusion that internal organs should be
removed of food fishes to avoid Thiaminase, this would
also indicate that using feeders is not considered safe
by the author, but I don't have it at hand right now. I
think it was by Sih-Yang Sim et al., who wrote the "A
Practical Guide to Feeds and Feed Management for
Cultured Groupers" in which the Thiaminase avoidance
recommendation is also briefly noted.>
Thanks for the quick response, Rich
<Welcome. Cheers, Marco.>
Re Thiaminase 1/5/12
PS: A quick look at my literature re thiamin deficiency
brought up a reference of a tropical fish species
showing symptoms of thiamin deficiency likely due
to high thiamine activity in a food fish. It's
Glezebrook an Campell "Diseases of Barramundi L.
calcarifer in Australia: A Review". I'm citing :
"Nutritional deficiencies have begun to appear in
cultured barramundi. Six out of a group of 60
fingerlings being reared in a plastic lined swimming
pool in Cairns were exhibiting abnormal swimming
behaviour, i.e. nearly vertical with exaggerated tail
movements. These fish were not interested in food and
showed no obvious internal or external lesions.
Microscopically, bilateral degenerative changes
(vacuolation) had occurred on both sides of the brain
and the peripheral nerves were also affected. In the
spinal cord, gliosis, i.e. swelling of the glial cells,
was evident, particularly ventrolaterally. There was
strong evidence to suggest that fish being fed to the
fingerlings was high in the enzyme Thiaminase. A dietary
change has since corrected the problem." So apparently
tropical predatory fishes can suffer from Thiaminase! I
don't know if they've been fed live or frozen fish,
though.
Re Thiaminase 1/7/12
This email was an addendum to an answer I send to
Richard re Thiaminase. It should go to where the earlier
answers went. I could not answer his original email at
this point, because I had it already answered and
deleted and couldn't find it in the deleted emails'
folder. Hope that's no problem.
Marco.
<Real good Marco. Will do. BobF>
Thiaminase... repeated
<PS: A quick look at my literature re thiamin deficiency
brought up a reference of a tropical fish species
showing symptoms of thiamin deficiency likely due
to high thiamine activity in a food fish. It's
Glezebrook an Campell "Diseases of Barramundi L.
calcarifer in Australia: A Review". I'm citing :
"Nutritional deficiencies have begun to appear in
cultured barramundi. Six out of a group of 60
fingerlings being reared in a plastic lined swimming
pool in Cairns were exhibiting abnormal swimming
behaviour, i.e. nearly vertical with exaggerated tail
movements. These fish were not interested in food and
showed no obvious internal or external lesions.
Microscopically, bilateral degenerative changes
(vacuolation) had occurred on both sides of the brain
and the peripheral nerves were also affected. In the
spinal cord, gliosis, i.e. swelling of the glial cells,
was evident, particularly ventrolaterally. There was
strong evidence to suggest that fish being fed to the
fingerlings was high in the enzyme Thiaminase. A dietary
change has since corrected the problem." So apparently
tropical predatory fishes can suffer from Thiaminase! I
don't know if they've been fed live or frozen fish,
though. Marco.>
Re: Thiaminase 1/7/12
Marco,
<Richard.>
I appreciate seeing others who take the responsibility
of keeping fish equally as seriously as I do. In
reading the wet web’s report on Thiaminase and other
topics I could tell how much thought and work went into
each report, which I respect. I have
a prejudice towards feeders, but if they truly are
harmful to a tank then I’ll beat that drum. I feel that
the problems associated with feeder fish are more
related to poor tank management and ignorance than in
the value of feeders. However, if
nutritionally they are inferior, or even just equal to,
pelleted diets, then there is no real use for them other
than to stimulate natural behavior. I think that
has to be the starting point.
<I agree.>
I found the paper you cited and yes there is no way of
knowing if the Barramundi were fed live or not. In my
experience older research did not see the relevance of
the distinction.
<No it didn't. The only thing you will find is that
fresh fish (and therefore feeders as well) has a higher
relation of thiamin to Thiaminase and therefore is
better than frozen food. The question is: is it safe?>
Several months ago I had a conversation with Jim Zajicek
of the USGS. He is a wealth of information on
Thiaminase research and was co-author of the Lake Trout
study. Very open individual and more than willing
to let you bend his ear. His email is
jzajicek@usgs.gov and I’d introduce yourself. His
bottom line was that unless you were interested in
breeding cold-water species, feeding live Thiaminase
containing fish was not a nutritional concern.
With regards to warm-water species, he
said it was a non-factor. I also contacted Andy Goodwin
at the Pine Bluff aquaculture facility and he put the
question to a panel of fish nutritionist and no one on
the panel voiced a concern. But, I fear you are correct
in saying that the research on the topic as it relates
to tropical fish is nonexistent.
<Yes, that's the problem. We have good points for both
opinions.>
This spring I am setting up an old tank system and should have some extra
space. I thought it would be fun to run a trial.
I want to take three groups of fingerling bluegill and
raise them on three unique diets and then compare the
results in the Fall. One group I would rear on
Gambusia (non-Thiaminase species), one on goldfish
(Thiaminase containing species) and a control on a
pelleted diet. Some feedback on what you think a
fair trail would look like, and any other comments,
would be very useful.
<This sounds like a very good idea. Results should be
published. Your control group will let you distinguish
between live vs. pelleted food, personally I'd add a
group fed with frozen, Thiaminase containing food to see
if the bluegill are affected at all during the
experiment (the barramundi apparently were affected much
quicker than trout). What also would be highly
interesting is the respective Thiaminase activities of
the food types used (I don't know if properly raised
goldfish fed with a healthy diet have a better
thiamin/Thiaminase relation than the ones you get from
crowded store tanks). I'd also add a second stage to the
experiment where fish showing symptoms are fed (if they
still accept food) a varied, thiamin rich and Thiaminase
poor diet to see if the deficiency diseases are
reversible at an early stage.>
Thanks. Sincerely, Richard
<Cheers, Marco.>
Re: Thiaminase
1/9/12
Marco,
<Richard.>
I’ll keep you informed on plans for a feed trial as they
develop. It is planned to begin in March when the
weather warms up. The first priority will be to
address Thiaminase. I like your idea of feeding
one group a diet known to be thiamin deficient. I
worry though as the number of unique diets increases
that the answers may get more muddled. I am
fortunate to have contact with some great people in the
industry. I don’t know where you are located
<Germany.>
but I spoke with Steve Lambourne from LA last week about
my plans. Steve’s family has been importing and
selling tropical fish wholesale for nearly 50 years.
He has one of the best reputations for quality on the
West Coast. He reminded me that for many years
goldfish were believed to be the perfect food.
Oscar owners fed their fish a goldfish exclusive diet
for years on end. This began to change when Jack
Gratzek and the University of Georgia linked a goldfish
exclusive diet to HITH. Adding variety to the diet
cured the symptoms. This is a point that we all
take for granted now. What is interesting though
is that we
forget that an all goldfish diet use to be the norm and
that it supported good health and achieved good
growth for many hobbyist. If Thiaminase is an issue with
feeding live then why did those keeping Oscars not then
find their fish lethargic, listless and dying after a
few months?
<A lot hobbyists did observe according symptoms... see
FAQs. Also, not all species are affected equally, we
don't even know if all goldfish contain thiamin and
Thiaminase and to what extent (this likely will depend
on the goldfish diet.>
What we have is a study of the effect of a Thiaminase
heavy diet on Lake Trout,
<and others...>
and an awareness that feeding frozen feeders leads to
thiamin deficient like symptoms, leading us to make the
illogical leap that feeders fed live will also cause a
thiamin deficiency. I say illogical because there
are decades of practical fish keeping experience which
say otherwise.
<Definitely disagree here as explained in detail
before.>
The problem is that in the absence of good information
we begin to draw conclusions that are not supported in
the literature
or in common practice, but that is the point and the
reason for the need for someone to step and start
conducting feed trials. Think about it though. Why
in the 80’s and 90’s were Oscars fed an all goldfish
diet able to
survive and grow to the size they did?
<Many did not.>
The symptoms of beriberi develop in months and are
pronounced. If thiamin deficiency was occurring it
would have been well documented, but it wasn’t. At
that time we didn’t know that goldfish contained
Thiaminase. If feeding live caused beriberi we
wouldn’t have needed to wait until 2005 for a study of
Lake Trout to bring it to our attention.
<It wasn't that study, which brought this to my
attention, but observed symptoms. The study along with
others only helped to explain the symptoms so far
without a definite cause.>
It would have been studied and we would already have the
data. The fact that the question hasn’t been asked has a
lot to do with the fact that the problem didn’t exist.
<Definitely disagree here, too, for the obvious reasons
written earlier.>
But, still the question has never been asked and studied
directly and until it is there are going to be
questions. Sincerely,
Rich
<Agree here. Cheers, Marco.>
Re: Thiaminase 1/10/12
Marco,
<Rich.>
Points well taken and I'll get started on a trial as
soon as the weather warms up.
I propose to use five unique diets on the trial:
Group A) Top quality commercial pellet
Group B) Exclusive Thiaminase containing live diet
(goldfish)
Group C) Exclusive Thiaminase containing frozen diet
(goldfish)
Group D) Exclusive non-Thiaminase containing live diet
(Gambusia)
Group E) Varied diet (goldfish, Gambusia, worms, snails
etc...)
Each group will contain 10 bluegill in 75 gallon plastic
tanks. Each group of ten will be weighed and
photographed prior to beginning the trial.
Periodically each group will be sampled. In the
Fall the entire group will be weighed and photographed
with an average weight and length given. If there is a
need individual fish can be dissected and inspected by a
vet.
I suspect that the live diets will outperform the
pellets.
<Bet the latter will be the most healthy group.>
That can't be assumed and I'll invest in an auto-feeder
to ensure the pelleted diet gets fed at regular
intervals. It will also be interesting to see how
the various live diets perform in relation to each other
and how long it will take for thiamin deficiency to
manifest in the frozen goldfish diet and or the live
goldfish diet.
<Yes, I'm very interested if/when fish show any
symptoms.>
The point of the trial is to get hard data. I
appreciate your interest and encouragement and will send
you updates as the trial develops. I also want to
encourage your sincere critique of the trial both as it
unfolds and in the planning stage.
<The only thing I can add at the moment is: With your
contacts to scientists that have worked on the topic, do
you have the possibility to get a measurement of
Thiaminase activity in one or two of your specific live
and frozen goldfish samples? In case symptoms occur one
could roughly compare them to other Thiaminase
containing types of food.>
You are not going to hurt my feelings by pointing out
something that I overlooked. Thanks.
<Kudos to you for undertaking such a study.>
Sincerely, Rich
<Cheers, Marco.>
Re: Thiaminase 1/10/12
<"Bet the latter will be the most healthy group." should
be the "last", being the varied diet (group E), not the
pellets. I don't know how good the pellets will perform,
but a varied diet in my opinion/experience should work
best.>
Re: Thiaminase 1/11/12
Marco,
<Rich.>
The author of the Lake Trout study said he could do the
testing for thiamin levels but that it was difficult and
expensive. Only maybe two labs in the world have
the experience to pull it off. You have to be able
to isolate the Thiaminase in the tissue so that it does
not interfere with the thiamin measurement. It is out of
my price range.
<Okay. So, let's assume the goldfish do contain a
similar activity as measured in earlier studies.>
However, most fish are a good source of protein and
muscle contains a lot of thiamin so it is assumed that
when feeding live of any species that there is an
abundance of thiamin available from muscle tissue.
It is simply a question of how much is absorbed in the
gut before Thiaminase deactivates it. As it was
described to me, "its all a matter of timing".
Also of note, fish require only a very small
amount of thiamin. Their needs are measured in
micro moles of B1. In your experience with thiamin
deficiency was it caused by using a frozen diet or did
you see a deficiency using a live diet?
<Mostly frozen (including various warm water aquarium
species). For live diets there are suspected cases of
Scorpaenoids, Morays and Antennariids and a small number
of freshwater predators such as Oscars fed exclusively
goldfish.>
Also, how long did it take for symptoms to appear?
<My final words in the article: "Thiaminase-containing
food will not be instantly lethal to your pets, but over
the long term can result in a slow decline in health." A
few months to about a year. I suppose with diets having
at least a very little variation, it could take longer.>
One more thing, I was rereading your article on
Thiaminase on the web last night. It is inaccurate
to say that Thiaminase will deplete existing B1 stores
in a predator fish (if I understood you correctly).
<I think you refer to the sentence: "Furthermore, any
fish fed such frozen fish will be consuming the
Thiaminase, and that will destroy some of the Vitamin B1
it already has." An "eaten" or "in the gut" at the end
would clarify that. This is about vit b1 in the stomach,
gut.>
Thiaminase does not cross the blood barrier and remains
in the gut where it passes out with the prey item.
<Yes, that's how I understood it.>
When feeding a varied diet it would then be important
not to feed Thiaminase containing diet at the same time
you feed a non-Thiaminase diet. Any B1 already in the
predator fish is unaffected. The concern with using
Thiaminase containing feeder fish is if enough B1 is
absorbed to meet the future metabolic needs.
<Yes. See the fish groups noted above: Scorpaenoids,
Morays and Antennariids: all have a slow digestion in
relation to the temperature they live in. Plenty of time
for Thiaminase to be active in the stomach. Barramundi
on the other hand as well as mammals seem to digest
faster compared to this group and still can suffer from
the deficiency syndrome ( I assume they were fed frozen
food, but don't know for sure for the barramundi). The
species seems to play a role with Thiaminase: I remember
a study where carp eggs (rich in Thiaminase) were fed to
catfishes and sunfishes, and only the catfishes
developed severe symptoms in the time of the study (a
few months as far as I remember, will look it up if you
want to read the study yourself). However, I have too
little information on specific pet fishes to make even
suggestions on which are more affected by a Thiaminase
rich diet and which are less.>
Rich
<Marco.>
Re: Thiaminase 1/11/12
Marco,
<Rich>
Sorry to have challenged some of what you wrote, but the
more we poke at this the more it make sense. That
is except for the barramundi paper which is an outlier.
I hadn't considered cold-water species of saltwater
fish.
<Me neither, the groups I named are subtropical to
tropical.>
That would be inline with the Lake Trout study. In
casual reading of claims of thiamin deficiency it would
also appear that juveniles are more susceptible than
adults. I haven't seen a paper supporting this, but it
would make sense too. With cold-water species it
would be important to not feed a continuous diet of
Thiaminase containing fish but to alternate weekly or
find an economical source of non-Thiaminase containing
fish. That seems to be a problem. Non-Thiaminase
containing species are usually more expensive and often
frozen which cause other nutritional concerns. For fry I
would recommend not feeding Thiaminase containing food.
Fry usually feed on insects and other high protein items
and don't have the opportunity to feed on other fish.
So there are good situations where Thiaminase can be a
problem. A manageable problem, but something that
we need to be aware of. But, I think we are
painting in very broad strokes because of a lack of
understanding of how Thiaminase works and that with
warm-water species Thiaminase is not an issue.
<I doubt the latter as explained earlier. Just think
about how long digestion takes at a frogfish or moray.>
Would you like me to recontact Jim at USGS and ask that
question of him specifically?
<Question? You mean if warm water fishes such as
barramundi or morays can be affected? Feel free to ask
for his opinion and maybe link him to the barramundi
study.>
I think he would be very interested in your observations
as well.
Sincerely, Rich
<Cheers, Marco.>
Re: Thiaminase 1/12/12
Marco,
<Rich.>
I'll put the question to him. It might be a while before
I get an answer.
<Okay.>
Should be interesting.
<Certainly.>
How are things in Germany?
<Quite fine. Thanks for asking. Surprising amount of
work even for geologists like me. Also an interesting
aquarium hobby scene with a lot in common to the US
scene, but also differences.>
I've never made it there. I bicycled once up from
Madrid to the edge of the Rhine but then headed back to
Paris for a flight out. I've always wanted to get back.
Rich
<Hopefully you'll find the possibility. Cheers, Marco.>
Re: Thiaminase 1/24/12
Marco,
<Rich.>
How are you? Hope all is well.
<Yes, thanks.>
Jim called from USGS and we talked about the barramundi
paper briefly before he had to go to an appointment.
As you know there is a lot of detail missing in the
account and he wasn't able to make much of it. He
is requesting the full article and some of the papers
cited but he noted that none of the cited literature
dealt with thiamin but rather B6 and B12.
<There are no citations within the paragraphs on
Thiaminase in this article...>
He wanted to be clear that I understood that even though
there was no definitive study that shows a link between
feeding tropical fish live Thiaminase containing fish
and thiamin deficiency that does not mean it does not
exist.
<As noted before I don't think there is such a study.>
He went further to explain that not all Thiaminase is
the same and its origins and purpose are very unclear as
well as how it is stored. In my opinion though, I
don't think the article should be elevated to the level
of being cited as a scientific reference to Thiaminase
as its conclusions are anecdotal and the literature
cited does not support the conclusion.
<I think you shouldn't simply exclude those references
of which you don't like the results... It's not much,
but it is as far as I know the only study at least
touching the topic of Thiaminase and tropical fishes.
And what needs to be noted, there is no study to my
knowledge (anecdotal or not) that shows Thiaminase is a
non-factor for tropical fishes.>
It gives the paper too much weight for what it is. If I
find a good citation that shows a link I will pass it on
to you.
<Okay.>
He agrees that feed trials would be a good place to
start and hopefully that will lead to a better
understanding of the utility of feeder fish and their
value. In reference to the saltwater species we didn't
discuss those. The reason I think was that he had no
experience and knew of no literature concerning them and
Thiaminase and so he saw no point in discussing it. We
are going to continue to communicate and I swap
citations. Take care, Rich
<Okay. Thanks for the update. Marco.>
PS: And again I have to send a second mail due to a
literature reference I did not mention: The book Marine
fish culture deals with Snooks and notes thiamin
deficiency (page 410). On page 515 it is also mentioned
that "Thiaminase-induced athiaminosis could occur in in
juveniles given fresh or frozen foods." I think more is
found in "Snook and Tarpon Snook Culture and Preliminary
Evaluation for Commercial Farming" by the same author
(1987), but I don't have it at hand at home (likely
would have to visit the lib). In addition to the one on
groupers (one of the earlier mails) this makes 3 studies
noting probable Thiaminase related problems with
tropical fishes.
Fresh Water Fish Roe as Food for
Salt Water Fish /RMF 7/19/11
Is fresh water fish roe a bad thing to feed to the inhabitants of a
reef?
<In general no; it's fine; though there are some toxic species...>
I ask because I want to start making my own fish/reef food and since I
like to fish, I would hate to waste the roe of fresh water fish that I
catch.
Thanks,
Chuck Furr
<If you/d eat it, it's fine for your marine fishes. Bob Fenner>
Fresh Water Fish Roe as Food for Salt Water Fish /Neale
7/19/11
Is fresh water fish roe a bad thing to feed to the inhabitants of a
reef? I ask because I want to start making my own fish/reef food and
since I like to fish, I would hate to waste the roe of fresh water fish
that I catch.
Thanks,
Chuck
<As an occasional addition it's unlikely to do harm and should provide
useful fats and proteins in particular. Certainly, feeding marine roe to
freshwater fish does no harm at all. But at a broader level, do
understand that many freshwater fish contain thiaminase, and that makes
them best used as occasional rather than regular additions to the diet,
and furthermore, there's a subtly distinct nutrient make-up in
freshwater animals when compared to saltwater ones. While freshwater
animals seem to be extremely
adaptable, many marine animals seem to depend on specific nutrients they
receive directly or indirectly from marine plankton, so foods with a
marine origin are crucial to the long-term success of marine livestock.
Hope this helps, Neale.>
Quick Food Question. Mysis/Mysids; Thiaminase content
6/24/17
I read through the articles and posts on the WWM site on this food, as well as
the article by Marco Lichtenberger regarding Thiaminase, but I couldn't find the
answer to this question; do Mysis shrimp contain Thiaminase?
<Yes, they do in moderate amounts following a study by Hondorp et al. (2005). In
my opinion they can be part of a varied diet, but should not be the only type of
food. Cheers, Marco.>
Re: Quick Food Question
Thank you! Avoiding Thiaminase 9/7/17
Hello crew,
I read the article on Thiaminase and I found it very informative. I was
left with a question, what am I supposed to feed my porcupine puffer? I
see that there are some non-Thiaminase fish offerings, but puffers do
not eat fish.
<Mmm; assuredly they do. Have seen several species of puffers consume
fish in the wild and captivity>
It caused fatty liver disease over time.
<Do you have reference/s for this assertion? Your intuition,
experience?>
It seems that everything I feed him is high in Thiaminase. Squid,
scallops, clam, mussel, oyster, shrimp is always in the mix. I do add
Boyd's Vita Chem to the food. Is this enough to counteract the effects
of the Thiaminase.
<To some extent; yes. B vitamins can be added to foods, water...>
I used to use Selcon, but the Boyd's seems to be a more complete multi
vitamin.
Thanks,
Jason
<I'd add in some whole (small) fishes or bits of fillet in this mix of
invertebrate fare. Bob Fenner>
|
|