Why mussel should not be feed to Congo spotted puffer?

[SourAngelfish]

Ah! Thank you! A possible explanation for his warning that makes good sense, and lends "some" credibility to the comment. I emphasize "some" because, as SourAngelfish states, a food containing thiaminase can be undesirable if it makes up a large percentage of the diet.

But...here's the actual statement:

This species should not be offered cockles, mussels, clams, oysters or similar mollusks.

Now, look at the emphasis: underline the whole thing, and italics on "not". Never, ever offer this stuff.

Sorry, not appropriate. Using these foods as one element of a varied diet would be completely acceptable, especially with vitamin supplementation. A warning regarding the use of these shellfish as a major component of the diet, along with a brief mention of thiaminase and its effects, would have been more useful...if that is indeed, his reason for the warning. As it stands, it seems suspiciously like one of the numerous cautions, warnings and statements that are copied and repeated ad nauseum on the internet without any actual understanding of why/if they are or are not actually true.

When someone makes a proclamation that is entirely untrue, or even questionable without clarification...it tends to throw doubt on anything else they state as fact.

agreed that this is a likely case of misinformation being repeated. Something that is far too common in this hobby.

 

[Fishman Dave]

My unfortunate view on this is pretty similar - if someone states “Not” to feed something, this to me says ever, and hence I want a pretty good explanation to follow, especially if this is within a care guide for keeping a fish. If no explanation is then provided, in my own opinion, the whole care guide is way less use than the white roll I find at the side of my toilet!
To me, It means all the rest of the information was probably copied and regurgitated from elsewhere.

My guess is that since these are freshwater puffers, then they wouldn’t come across mussels in nature so that’s a good reason not to include much of them in their diet, but I don’t know many tropical fish that frequently eat flake foods in nature either.

If someone could give a valid reason for “not” feeding mussels ever to this puffer then I would listen.
If you have fed it mussels already and it didn’t drop dead - then maybe as John says this maybe ought to have said “feed sparingly” and of course had an explanation why.

Cooked Mussels 100% of the time will no doubt have deficiencies in some vitamins, but there are fish out there that have developed to live on just one food only, and survive, that’s nature, nature finds a way. Doesn’t mean I condone just feeding one food by the way! But we often find some fish that will accept nothing else (or seem to, as I don’t watch them 100%of the time), and that is my tyre track eel.

Note how I just regurgitated everything everyone else has said above! ?

 

[Midwater]

...contain thiaminase ...

I have often wondered about Thiaminase. I understand that it is an 'anti nutrient'.

It does seem though, that most aquatic predators would naturally consume quite some quantities of Thiaminase rich live food continuously. Do predators have a lesser effect, and is the danger of Thiaminase over exaggerated?

I have long time fed most of my fish with a fair proportion of live ghost shrimp. With my predators, I alternate with live tilapia fry (apparently low in Thiaminase).

 

[Kieraivingston]

I feed them mussels that are without shell

 

[SourAngelfish]

I have often wondered about Thiaminase. I understand that it is an 'anti nutrient'.

It does seem though, that most aquatic predators would naturally consume quite some quantities of Thiaminase rich live food continuously. Do predators have a lesser effect, and is the danger of Thiaminase over exaggerated?

I have long time fed most of my fish with a fair proportion of live ghost shrimp. With my predators, I alternate with live tilapia fry (apparently low in Thiaminase).

The subject seems to be clouded in a lot of mystery and confusion. Best way to avoid it is to keep a varied diet. Even then, some fish seem to function fine fed full diets of thiaminase rich foods on occasion so I find it to still be very confusing.

Some predators, gar for example, naturally produce thiaminase. Are these fish immune to its effects when ingesting thiaminase rich fish?

Potentially some fish are more vulnerable to thiamin deficiencies? I’d point particularly to south and Central American cichlids as many environments that these cichlids reside in have little to no thiaminase carrying fish. Characins and cichlids for example tend to not carry the enzyme.

 

[jjohnwm]

On the face of it, it would seem reasonable to assume that certain predatory species, which naturally feed upon thiaminase-containing prey species, would be more resistant to the effects of low thiamine levels than others that don't normally encounter the enzyme in nature, at least not in large quantities.

I don't understand many of the details of thiaminase poisoning. Are some prey species so rich in the enzyme that feeding them not only provides no thiamine to the predator, but also degrades the thiamine present in other foods which are also eaten? Does the enzyme accumulate in the predator's body and remain active for some period of time after ingestion, thus affecting other foods? Or does thiaminase only degrade the thiamine that would otherwise be present in the thiaminase-containing food item, leaving the predator free to derive thiamine from other foods eaten at the same time?

Whichever the case may be, it might be a stretch to assume that the "care-sheet" in question has enough of a basis in actual science that we even need to interpret what it means, or to extrapolate back to find out if its "data" is based upon any actual fact. Sure, it might be...but it might also be just plain wrong. Usually, the simplest answer is the correct one.

 

[kzimmerman]

I think that it may be because they don’t need their teeth ground down as much, so they shouldn’t be fed hard foods. Mussels on the half shell or no shell is fine.
As I recall, thiaminase is found primarily in saltwater organisms. I have a good book that deals with the subject somewhere, I will try to dig it up today. They show fish that were fed a normal diet and the fish that were fed a diet rich in thiamine. The control group looked good and healthy, the experimental group looked sick and starved. I wish I could remember more, I will try to come up with that book to get the full scoop today.

 

[kzimmerman]

Wasn’t exactly as I remember, but there it is.

 

[Midwater]

I have been live feeding for twenty years, and never seen anything like that picture.

 

[jjohnwm]

The caption states "when raw seafoods are used as feed regularly..." and then displays that sad little fish showing us what will supposedly occur. It's a predatory salt-water fish; if it doesn't spend its entire life in nature eating "raw seafoods"...just what exactly is it supposed to eat? Tofu??? Do Snook typically carry around little waterproof Hibachis to cook their food and eliminate the thiaminase boogeyman?

Again, a poor presentation of the facts by that author. Thiaminase isn't limited to marine fish, and isn't present in all species. As long as the diet contains a good percentage of non-thiaminase items, it isn't a concern, according to literally every article I have read. Does this stuff occur to fish that are fed a diet consisting of just one species of prey item, which happens to contain thiaminase? Sure, maybe...that's just another reason to avoid feeding predators that way.