Anisakis worms and peshat in Kukyanei, according to Rashi and Rabbenu Tam

There are two main ways of understanding the gemara's discussion of worm parasites called kukyanei, that of Rashi, and that of Rif and Rabbenu Tam. I would like to explore each.

אמר רב ששת בריה דרב אידי קוקיאני אסירי מאי טעמא מעלמא אתו מתקיף לה רב אשי אי מעלמא אתו לישתכחו דרך בית הריעי איכא דאמרי אמר רב שישא בריה דרב אידי קוקיאני שרו מאי טעמא מיניה גבלי אמר רב אשי פשיטא דאי מעלמא קא אתו לישתכחו דרך בית הריעי והלכתא קוקיאני אסירי מ"ט מינם ניים ועיילי ליה באוסייה 

What are these קוקיאני? They are some sort of parasite. In Berachot 36a, barley-flour is harmful to man in creating tapeworks, kukiani:

But has not R. Zera said in the name of R. Mattena reporting Samuel: Over raw cabbage and barley-flour we say the blessing 'by whose word all things exist', and may we not infer from this that over wheat-flour we say 'who createst the fruit of the ground'? — No; over wheat-flour also we say 'by whose word all things exist'. Then let him state the rule for wheat-flour, and it will apply to barley-flour as a matter of course? — If he had stated the rule as applying to wheat-flour, I might have said: That is the rule for wheat-flour, but over barley-flour we need say no blessing at all. Therefore we are told that this is not so. But is barley-flour of less account than salt or brine, of which we have learnt: Over salt and brine one says 'by whose word all things exist'? — It was necessary [to lay down the rule for barley-flour]. You might argue that a man often puts a dash of salt or brine into his mouth [without harm], but barley-flour is harmful in creating tapeworms, and therefore we need say no blessing over it. We are therefore told that since one has some enjoyment from it he must say a blessing over it.

So too in Shabbat 109b:

R. Joseph said: Hyssop is abratha bar hemag; Greek hyssop is abratha bar henag. 'Ulla said: [Hyssop is] white marwa [sage]. 'Ulla visited R. Samuel b. Judah [and] they set white marwa before him. Said he to them, That is the hyssop prescribed in Scripture. R. Pappi said, It is shumshuk. [marjoram]. R. Jeremiah of Difti said: Reason Supports R. Pappi. For we learnt: 'The law of hyssop [requires] three stalks [each] containing three calyxes'; and shumshuk, is found to have that shape. For what is it eaten? — [As a remedy] for worms. With what is it eaten? With seven black dates. By what is it [the disease of worms] caused? — Through [eating] barley-flour forty days old.

Rashi in Shabbos defines these קוקיאני as worms of the בני מעים. In terms of the gemara in Chullin, though, he understands that the parasitic worms under discussion are in the liver and lungs of an animal. Thus:
קוקיאני - תולעים שבכבד ושבריאה:

Let us first learn the gemara through Rashi's eyes. Once again, it is:

אמר רב ששת בריה דרב אידי קוקיאני אסירי מאי טעמא מעלמא אתו מתקיף לה רב אשי אי מעלמא אתו לישתכחו דרך בית הריעי איכא דאמרי אמר רב שישא בריה דרב אידי קוקיאני שרו מאי טעמא מיניה גבלי אמר רב אשי פשיטא דאי מעלמא קא אתו לישתכחו דרך בית הריעי והלכתא קוקיאני אסירי מ"ט מינם ניים ועיילי ליה באוסייה

There are two versions of the exchange -- I would argue based on the terminology of איכא דאמרי, girsaot -- which are brought down in our gemara.

The first:

אמר רב ששת בריה דרב אידי קוקיאני אסירי מאי טעמא מעלמא אתו מתקיף לה רב אשי אי מעלמא אתו לישתכחו דרך בית הריעי

Rav Sheshet son of Rav Idi said that kukyanei -- parasites found in the lungs and liver of animals -- are forbidden. What is the reason? They came from the outside. Rav Ashi objected to this: If they came from the outside, we should find them by the anus, at the end of the digestive tract.

I have seen some interpretations of this that everyone agrees they would not have come from the mouth, for they would have been digested. Rather, they came from the anus. Perhaps. I have reasons to think otherwise. and so for this post I am operating under the assumption that they think it came from the mouth.

And so, I would assert that the assumption here is that they came from the mouth, and went from there into the trachea and from there into the lungs and the liver. How is this possible? Because Chazal were operating on the different biological assumptions than we are. To get to the lungs from the trachea is trivial. What about the liver?

See the gemara in Chullin 48b:

ההיא מחטא דאישתכח בחתיכה דכבדא סבר מר בריה דרב יוסף למיטרפה אמר ליה רב אשי אילו אשתכח בבשרא כה"ג הוה טריף מר אלא אמר רב אשי חזינא אי קופא לבר נקובי נקיב ואתאי אי קופא לגיו סמפונא נקט

That is, if a needle is found in the liver, it may be permitted if it is facing a particular direction, because we may assume that it passed via the vena cava, which extends from the trachea to the liver. See Chullin 49a, and Rashi there, based on Chullin 45b, which says that the simpon extends from the trachea to the liver. Rashi writes:

מכשר - כיון דבסמפונא אישתכח אמרינן מי מיכוונה להכנס בסמפון זה אלא דרך הקנה נכנסה והקנה וקנה כבד סמוכין זה לזה בהתחלקן סמוך לריאה וגם קנה הלב וקנה הכבד מתחלקין לסמפונות בראשן האחד וי"ל שנכנסה מסמפוני הכבד לסמפוני קנה הכבד ומשם עלתה לכבד דרך הסמפונות:

This does not accord with our modern understanding of biology, and this is a strong question whether we should be mattir for such a needle found in the liver nowadays. But it explains how, according to Rashi, the worm parasite could get from the mouth to the trachea to the liver.

And that is why Rav Sheshet son of Rav Iddi forbids. Rav Ashi argues with him. For if it is ingested in the mouth, we should expect that it would be found all along the digestive tract, including the end of it, for some worms will be swallowed rather than going into the trachea. Therefore, they must have simply spontaneously generated in these organs of the animal.

That was the first of the two versions of the dispute. The second:

איכא דאמרי אמר רב שישא בריה דרב אידי קוקיאני שרו מאי טעמא מיניה גבלי אמר רב אשי פשיטא דאי מעלמא קא אתו לישתכחו דרך בית הריעי

Rav Shisha son of Rav Idi said that parasitic worms -- in the liver and lungs -- are permitted. Why? Because they spontaneously generated. Rav Ashi reinforces this position, by noting that they could not have come from outside the animal, for if so, we would have found them at the end of the digestive tract as well.

In both versions, Rav Ashi permits, though in the first version, he has a disputant.

If Ravina and Rav Ashi were in charge of the chatimas haTalmud, and are sof horaah, it is strange that there are different versions of a dispute involving Rav Ashi. And that the halacha is not like Rav Ashi, and for a reason not explicitly mentioned by his disputant. The next statement, the hilcheta, is presumably the setama d'gemara from Savoraim or later. At any rate, the gemara concludes:

והלכתא קוקיאני אסירי מ"ט מינם ניים ועיילי ליה באוסייה

The halacha is that these parasites found in the lungs and livers of animals are forbidden. For when the animal sleeps, the parasite crawls into its nostrils.

To explain, it crawls into its nostrils, and from there to the trachea, and from there to the lungs and to the liver, as explained above. The animal will not be swallowing it as well, while awake, so it won't be found in the end of the digestive tract.

All this works out well, except for the science of the circulatory system, and of spontaneous generation, being incorrect.

Regardless, worms found in the flesh would be entirely separate, for they would be assumed to have been spontaneously generated. Because the assumption (seen elsewhere) is that worms cannot dig through flesh.

That is one way of understanding the gemara. Rif understands it differently, that it refers to worms in the belly of the fish.

Thus, the Rif summarizes the gemara as follows:

וקוקאני דאינון תולעים

שבמעי הדגים אסירי מאי טעמא מעלמא קא

אתו דמינם נאים כוארא ועייל באוסיה:

Kukaini -- which are worms in the bellies of fish -- are prohibited. What is the reason? They come from the outside. For when the fish sleeps, the parasite comes and enters it nostrils.

This is a good summary of the conclusion of the gemara, but does not give us the meaning at each stage. Perhaps this is influenced by another gemara which speaks of a parasite entering a fish's nose. (Indeed, if it comes from the setama, we should it expect that he gets it from some other gemara, from a statement from a named Amora.) Or else it is influenced by Rabbenu Tam's question:

קוקיאני אסירי. פי' הקונטרס תולעים שבכבד ושבריאה וקשיא לר"ת דלאידך לישנא דשרי תקשי ליה מברייתא דבסמוך דואת נבלתם תשקצו לרבות דרנים שבבהמה אע"ג דמינה קא גדלי אלא אומר ר"ת דבדגים איירי הכא והא דאמר כי ניים עייל ליה באוסיא אשכחן בדגים כי האי גוונא בפ' המוכר את הספינה (ב"ב דף עג:) דאמר רבה בר בר חנה חזינא ההוא כוורא דיתבה ועיילא ליה טינא באוסייה:

According to the second lashon, that they should be permitted, the brayta which follows should have been cited. That brayta, cited within a more general discussion, and ensuing discussion, was:

תולעים דרני דבשרא אסירי דכוורי שריין ... ש

א"ל רב משרשיא בריה דרב אחא לרבינא מאי שנא מהא דתניא  (ויקרא יא, יא) ואת נבלתם תשקצו לרבות את הדרנים שבבהמה 

א"ל הכי השתא בהמה בשחיטה הוא דמשתריא והני מדלא קא מהניא להו שחיטה באיסורייהו קיימן אבל דגים באסיפה בעלמא מישתרי והני כי קא גבלן בהיתרא קא גבלן

Thus, we see that despite spontaneous generation, the worms in flesh are forbidden, since they were initially forbidden because of ever min hachai and shechita did not mattir them. So too, one would think, for worms found in the liver and lung! That the gemara did not ask this indicates that it is not a relevant question, which should indicate that we are not discussing spontaneously generated worms in animals. Rather, we must be discussing fish.

(Since Rashi was not afforded the opportunity to respond, I will offer a response on his behalf. This is a question and proof, but an answer is always possible, no matter how far-fetched. I would note that Rashi has a very precise definition of darnei:

דרני - תולעים הנמצאים בין עור לבשר כשמפשיטין הבהמה ובלע"ז גרביליי"ש:

That is, worms found between the skin and the flesh. This could be very different from worms found within the flesh itself, or within internal organs of the animal. Indeed, if this is all misevara, that first it is ever min hachai and that shechita does not work, why does there need to be an explicit derashah from the pasuk, of ואת נבלתם תשקצו לרבות את הדרנים שבבהמה?! And if it is a derashah, then it makes sense that only the darnei, which the brayta mentions, are included in this novel law and inclusion. This might operate by the derasha informing us that shechita is no mattir for these. Alternatively, leave aside the derasha and operate only on the logic of Ravina. Why should shechita not be good, when it is valid for a shalil? Maybe because these darnei are not actually in and part of the flesh, but are outside it next to the skin. But worms in the flesh or organs would be covered by the shechita. And therefore, only darnei are problematic. Either could be a strong answer to Rabbenu Tam on Rashi's behalf, and so I would not be so quick to dismiss Rashi. This, by the way, could have halachic repercussions.)

Assuming we agree with Rabbenu Tam that we must be discussing fish, then we must be discussing parasites found in the belly of the fish. Why? Not only because this is what Rif explicitly says, but because the brayta he references and the ensuing discussion made clear that darnei in fish, which are in the flesh, or out of the flesh but under the skin, and therefore certainly in the flesh itself, are muttar! It must then be talking about worms found in the stomach of the fish. Let us consider this entire gemara, then, according to Rabbenu Tam.

We can once again assume that the gemara is worried about whether they came from the anus, or else that it comes from the mouth. I will assume that it is worried about them coming from the mouth, which is more straightforward, in my humble opinion.

The first version of the discussion:

אמר רב ששת בריה דרב אידי קוקיאני אסירי מאי טעמא מעלמא אתו מתקיף לה רב אשי אי מעלמא אתו לישתכחו דרך בית הריעי

Rav Sheshet son of Rav Idi declared that parasitic worms -- found in the bellies of fish -- are forbidden. What is the reason? They came from the outside -- for since they were found in the belly, we will worry that the fish swallowed them, rather than their being spontaneously generated. Rav Ashi objected to this: If they came from outside, we should find it by the end of the digestive tract, since they come in with the food, and we do not. Therefore, they must be spontaneously generated, and should be permitted.

The second version of the discussion:

איכא דאמרי אמר רב שישא בריה דרב אידי קוקיאני שרו מאי טעמא מיניה גבלי אמר רב אשי פשיטא דאי מעלמא קא אתו לישתכחו דרך בית הריעי

Rav Shisha son of Rav Idi said: Kukianei -- parasitic worms in the muscle tissue of the bellies of fish -- are permitted. What is the reason? Because they grow from them. Rav Ashi said: This is obvious, for it they came from the outside, we should find them in the end of the digestive tract.

Despite all the named Amoraim stating categorically that these parasitic worms are permitted, and one of them  is Rav Ashi who is sof horaah, the gemara rejects this and rules otherwise, that it is forbidden. On what basis?

והלכתא קוקיאני אסירי מ"ט מינם ניים ועיילי ליה באוסייה

They are forbidden because perhaps while the fish slept, the parasitic worm crawled in its nose. Since I am explaining the gemara up to this point as the concern being that it entered via its mouth (rather than the anus), how is entering via the nose different from entering via the mouth. Perhaps that it stayed there until the fish was no longer digesting its food -- maybe after death or some other time -- and entered the stomach or stomach muscle. Therefore, it would have come from the outside.

How does the setama degamara -- indeed, how do we -- know that a fish has nostrils, and that a parasite might enter into it? Tosafot refers us to the gemara in Bava Batra, daf 73b:

Rabbah b. Bar Hana further stated: Once we were travelling on board a ship and saw a fish in whose nostrils a parasite had entered. Thereupon, the water cast up the fish and threw it upon the shore. Sixty towns were destroyed thereby, sixty towns ate therefrom, and sixty towns salted [the remnants] thereof, and from one of its eyeballs three hundred kegs of oil were filled. On returning after twelve calendar months we saw that they were cutting rafters from its skeleton and proceeding to rebuild those towns.

I would note that a likely assumption -- made by Rashi there -- is that when the worm entered the fish's nostrils, the fish died, and that was why the water cast up the fish.

Now, can we really derive facts about nature from such a fantastic story? Perhaps, either because it is true, intended as true, or is metaphor predicated on true facts. So we can derive that a fish has nostrils, and that a parasite can enter its nostrils.

However, from the story, it seems that the parasite entering its nostrils was fatal. Perhaps because it entered the brain?

A stronger objection. Looking at the actual world, yes, a fish does have nostrils. However, this is purely as an olfactory sense. A fish's nostrils do not lead to the throat; not to the respiratory system and not to the digestive system. If so, there is a major flaw in Rif and Rabbenu Tam's peshat in the gemara.

I would maintain we then have two choices. First, we can simply say that Rif and Rabbenu Tam are wrong, and Rashi is right. I answered on Rashi's behalf, above, and so Rashi is in good standing.

Second, we can say that Rif and Rabbenu Tam are absolutely correct in explaining the gemara, but the setama de-gemara itself was wrong. I would gravitate towards this second explanation. After all, this הלכתא is likely setammaitic, and I have observed on many occasions that the setama draws from other sources. Tosafot was extremely perceptive in identifying the fish parasite in nostril from Rabbah bar bar Chanah. And this could have been an objection to Rav Ashi pulled in its entirety from the gemara, rather than perception of reality in the physical world. (I make a similar claim regarding how White Elephants Can't Jump. Not that Tosafot was wrong about elephants jumping, but rather Tosafot accurately identified the gemara's intent. It was just the setama which had the reality wrong, and pulled some information about elephants from another gemara.)

I will close, for now, with two possible conclusions.

Conclusions
(1) If we revert to Rashi, I would assert that at the least, Rashi considers worms in the flesh itself, rather than between flesh and skin, to be shechted and entirely permissible. This would overturn currently understood halachah. Further, the idea of a parasite entering via the nose is stammaitic, and perhaps we should rule like Rav Ashi who is sof horaah, and permit the worms in the organs as well. Of course, this could possibly clash with modern scientific understanding of how these parasites operate, but I'd like to consider this interaction in a separate post.

Rashi does not even discuss the stomach, and from my reading would consider them (almost) certainly forbidden, but I could imagine arguing for permitting worms found in the stomach via a slight variation of Rashi's presentation. But whatever is said for animals would likely apply to fish as well, and so just as worms in the abdominal cavity of animals are prohibited (according to Rashi), so too in the abdominal cavity of fish. (Except of course that the "nostril" answer would not hold true for fish, but would for animals.)

(2) If we maintain Rif and Rabbenu Tam's reading, then I think we should dismiss the setama. It was post-Rav Ashi, argues with him (the redactor!), and does so based on a mistaken understanding of biology drawn from a mistaken reading of a distant gemara. Yes, it seems that based on modern science the Amoraim are also erring in science, but we might be able to answer this up (in a separate post). Therefore, in both versions of the dispute, we should rule like Rav Ashi, and permit even the worms found in the stomach of the fish.