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Worms in Fish - the Recent Tumult

Authored by Rabbi Moishe Dovid Lebovits, Reviewed by Rabbi Benzion Schiffenbauer Shlita

This article first appeared in Halachically Speaking, Vol 6 Issue 9.
Copyright ©' 2010 Halachicaly Speaking. All rights reserved.
Reprinted with permission of the publisher.

This article is intended for limud haTorah purposes and is not to be relied upon halacha l’maseh. One should not draw any conclusions after reading this article without first consulting with his Rav. This article in no way expresses the opinion of the KOF-K.

By the time you hold this article, much time has passed since the tumult regarding the anisakis worm erupted. Many Rabbonim Shlita from Eretz Yisrael1 signed on a kol koreh to prohibit fish with the anisakis worm. On the other hand many Rabbobnim in America and other locales hold that this is not an issue.

According to the stringent opinion, many fish are prohibited, such as wild salmon (see footnote).2 Indeed some kashrus organizations do not permit those fish in their establishments.3 It is noteworthy that the anisakis worm is not the only worm that affects fish. There are tens of thousands of worms in the sea4 which are eaten by different kinds of kosher fish, many of which are eaten by the kosher consumer.5

It is important to realize that the issue of worms in fish is not new.6 This article will present the halachos of worms in fish, and explain the opinions for permitting and forbidding fish which are infested with the anisakis worm. We will discuss the sugya of worms in fish and then deal with the specific worm at hand.


The topic of worms and insects as they relate to food, fish, and water has been discussed for hundreds of years. The Torah discusses the issur of consuming worms in a few places.7 One who eats an insect or worm can transgress numerous aveiros.8 Why the severity of this mitzvah? The Pri Chadash 9 explains that these creatures are found all over, and one needs an extra zehirus to make sure he is not nichshal in this aveirah. Therefore, the Torah placed so many lavin in order to stress the need for particular care in regard to this prohibition.


The Gemarah10 says that fish that are infested with a kukyanei worm are forbidden, while fish that are infested with a darna worm (found between the skin and flesh of the fish) are permitted.11 The difference is that the kukyanei worm enters from outside of the fish as a worm, while the darna worm hatches inside the fish and it is considered part of the fish.12 To demonstrate that the darna is permitted, the Gemarah13 relates that Ravina asked his mother to mix the fish together with the food before serving it so the worms would not disgust him. The Shulchan Aruch14 says worms found in the internal organs of the fish ossur the fish, and worms found between the skin and the flesh or in the flesh are permitted.

Kukyanei15 and Darna

The kukyanei worm is forbidden because it comes from the outside (it enters the nose of the fish while the fish is sleeping).16 The opinion of the Pri Megadim17 (and others)18 is that the kukyanei is forbidden since it is a sofek if it comes from the outside or inside of the fish.

Darna comes from the fish itself and therefore is permitted.

The opinion of the Rashba19 (and others)20 is that darna is permitted because it is “for sure” known that it comes from the inside, as opposed to kukyanei which enters from the outside of the fish. According to this all worms found in the flesh or between the skin and the flesh are permitted (we will see that there are grounds to permit them even if they came from the outside).21

Thus, the kukyanei is forbidden because it comes from the outside, and the darna is permitted (when it is found in the flesh or between the skin and flesh) because it hatched in the flesh itself.22

Opinion of the Rambam

The opinion of the Rambam23 is that the location of the worm in the fish is irrelevant. As long as there is a possibility that it came from the outside, it is forbidden. His opinion is not accepted l’halacha.24 For an explanation as to how the Rambam would learn the Gemarah, refer to the footnote.25

In the Flesh and the Other Organs

Harav Yisrael Belsky Shlita says that all worms come from the outside. However, if the worm can penetrate the walls of the host’s intestines, then it is considered part of the fish. The Hag’oes to the Sharei Dura26 says that a worm which can penetrate the intestinal wall and enter the flesh is permitted. If it cannot, then it is not considered part of the fish, and is forbidden because of a sofek that it is not part of the fish.27 This has ramifications to the anisakis as will be discussed below.

Chazal Permit Worms in the Flesh

From the sources quoted above, we can maintain that when Chazal permitted worms found in the flesh, they were referring to all fish. If certain types of worms in the flesh were prohibited, Chazal would have provided some sign to tell the difference.28

If We Know That it Came From the Outside

As we mentioned above, a worm found inside the flesh is permitted since it came from the inside. Those who prohibit this worm maintain that the Gemarah only permits those worms whose origin is unknown to us, as we can assume that they came from inside. However, if we know for a fact that the worms came from the outside, then they are prohibited even if they are found in the flesh.29

On the other hand, those who permit this worm say that when the Rishonim mention that worms which are found in the flesh are permitted because “we know for sure” they came from the inside, it is not a necessary condition to permit them; rather, it is a reason. If it were the condition, the Shulchan Aruch and all the Rishonim would have mentioned this in their writings. Therefore, the worms are permitted even without the reason.30

Thus, the logic to permit these worms applies even if we can scientifically conclude that the worms originated outside the fish.

Is Darna a Specific Worm?

It should be stressed that darna is not a specific worm, but is a generic term that Chazal used for any worm.31 Others claim that the Gemarah was referring specifically to darna, and if we know of a worm that penetrated a fish it is forbidden, even if it is found in the flesh.32 This opinion is not accepted by other poskim.

Insects on the Skin of the Fish

The Chochmas Adam33 says that insects or worms found on the outside skin of the fish are not allowed, since they do not grow in the fish.


What is anisakis, and how does it end up in fish?

Scientists generally agree that worms have a life cycle.34 The seal eats a fish called a cod which contains larvae. The larvae make eggs in the stomach of the seal, which enter the sea with some of the excrement. The eggs hatch into small larvae which are eaten by crustaceans. These crustaceans (often little shrimp) are eaten by fish, which are in turn eaten by larger fish such as salmon. The entire fish is absorbed in the host fish but the worm is not digested. The worm then burrows through the wall of the gut and encysts in a protective coat, usually on the outside of the visceral organs, but occasionally in the muscle or beneath the skin. The life cycle is completed when an infected fish is eaten by a marine mammal, such as a whale, seal, or dolphin and then the life cycle of the anisakis begins again.35 The worm is white and translucent in the flesh of the fish.36

Is it a New Worm?

Why the focus on this worm as opposed to other worms, and why now? Why didn’t anyone discuss the halachic implications of this earlier?

Some claim that this worm was not around in the time of Chazal. Therefore, it is not included in the heter if it is found in the flesh of the fish.37 They explain that today’s dirtier waters support more species of worms.38 In addition, the anisakis worm has developed in fish more frequently than in earlier years, so it is more common today.39

In truth, the anisakis worm is not a new worm. Actually, there are no new species of worm. The anisakis worm has been discussed in literature at least 700 years ago. This worm was around from time immemorial.40 The only increase in anisakis is the amount of cases reported of humans ingesting this worm (see below).41

In Flesh and Internal Organs

One of the main arguments to prohibit this worm is that since it is found in the internal organs (i.e. stomach) and the flesh of the fish, it is an indication that it penetrated the fish from the outside.42 However, according to the Hag’oes to the Sharei Dura above this is not a reason to forbid the fish at all. Since the worm enters the flesh of the fish through the stomach, it is an indication that this is the permitted kind of worm. Only those worms that are found exclusively in the stomach are ossur, because of a sofek whether they are part of the fish. If we see these worms in the stomach and in the flesh, then it is the permitted kind,43 and there are scientific reports that the worm is found in many cases in the flesh of the fish.44

In addition, some extrapolate the opinion of the Hag’oes to the Sharei Dura as possibly being the opinion of the Tur and Shulchan Aruch as well.45

Coming From the Flesh – Spontaneous Generation46

For years, scientists believed in spontaneous generation, which means that a female and male are not needed to reproduce, and creatures can grow from dirt and rot.47 Louis Pasteur finally disproved this theory in the late nineteenth century. The simple reading of the Gemarah that worms grow in the flesh of the fish would seem to indicate that Chazal held of spontaneous generation.48

However, there is an alternative way to explain the Gemarah.

We find a similar issue concerning lice.

The halacha is that lice may be killed on Shabbos,49 since they are not created from the mating of a male and female.50 Many explain that lice are spontaneously generated. This was the accepted theory for many years.

However, many explain the Gemarah that the reason why lice may be killed is they are so small and unrecognizable (unless they are on a shaft of black hair). Therefore, they are considered as nothing (see below), and viewed as a product of dirt. However, there is no proof from here that there is such as notion as spontaneous generation.51

Some maintain that even if Chazal’s given reason does not apply today, the halacha does not change.52 Others maintain that since today we see that lice do reproduce one may not kill them on Shabbos.53 The custom does not follow this opinion.

>Harav Yisroel Belsky Shlita explains that the lice actually do reproduce. They are parasites, feeding off the host’s protein. In the case of a human it is the head. This is not considered reproducing to the extent that they may not be killed on Shabbos, but they are not considered spontaneously generated.54

Concerning worms in fish, Harav Yisroel Belsky Shlita holds that there is no such thing as a worm being born from the flesh of the fish. All worms come from the outside. However, Chazal tell us that if it is found in the flesh of the fish it is permitted since it is considered part of the fish itself even if it originated from the outside.

Harav Yosef Mordechai Zilber Shlita from Machzikei Hadaas in Eretz Yisroel55 says that the worm lays eggs in the fish, and the larvae make their way into the flesh of the fish and grow into worms. This is considered “comes from the flesh,” even though the egg came from the outside. According to this explanation, there is no contradiction between science and halacha.

Others say that although the scientific facts seem to contradict Chazal, we follow the halacha anyway.56 Chazal permitted the worm based on the logic of spontaneous generation. Even if we reject that concept completely, we cannot change the halacha.57 Therefore, if Chazal said a fish is permitted it is permitted even if the rationale is refuted by science.

Some draw a distinction between worms which are found solely in the flesh (permitted), and those which are found both in the flesh and the stomach (prohibited). Therefore, there is no conflict between science and Chazal.58 This seems to imply spontaneous generation to some extent. It seems odd that the Gemarah would not make mention of such an important point. In addition, we quoted the opinion of the Hag’oes to the Sharei Dura that if the worm goes into the intestine and back into the flesh it is permitted.59

Have Times Changed?60

Some say that various species of worms exist today that were not around at the time of Chazal. These new worms come from outside and are not permitted.61 Chazal do not discuss worms which penetrate the flesh from outside for the simple reason that these worms did not exist during the time of Chazal. The problem with this approach is that the concept of “times have changed”62 only applies to specific ideas, such as people being weaker. In addition, it cannot apply to a worm which was around for thousands of years.63

Entering After Death

One of the principle arguments to prohibit the anisakis worm is that it travels from the stomach into the flesh of the fish after the fish dies (this is known as postmortem migration.) Therefore, the worms in the flesh are prohibited, since the heter only applies if the worm was found in the flesh and not in the stomach.64

It should be noted that this claim is debated in scientific journals, many of which say that there is no postmortem migration at all.65 The reason for any postmortem migration is not know to scientists.66

Can’t Be Seen

The Torah is eternal. Even though there are microscopes and other technological advances that allow us to see things that were invisible until now, we are not required to act based on this new knowledge.

The larvae which enter the bodies of the fish are microscopic. They are about 200-300 microns long and 14 microns wide.67 There are many poskim that maintain that the Torah was not given to malachim, and if the worm is not visible through regular means of sight then one does not have to look for it with a microscope. This notion is quoted by the Aruch Hashulchan,68 Machzei Eliyahu,69 Igros Moshe70 Harav Ovaida Yosef Shlita,71 and others.72 This is another reason to permit these worms.73 There are some who opine that even if one needs a magnifying glass to see the worm it is considered nonexistent.74 This is not the overwhelming custom, since in most cases the magnifying glass merely allows a better look at the insect, but it is visible without the magnifying glass.75

This would apply even if the larvae grows in the fish and is now visible.76 Those who forbid the worms do not consider them “invisible”.77

Everyone agrees that worms which are found solely in the intestines are forbidden, since there are many insects found in the intestines and it is hard to differentiate between those which can and cannot be seen. Therefore, they are all ossur.78

Some forbid anisakis on the assumption that they are visible when they enter the fish. However, one cannot make such a technical difference between the kinds of worms. We cannot differentiate and know which worms are visible when it enters the fish.79

In some fish, the insect can only be seen in the flesh through ultraviolet light; one does not have to go through that process.80

How Did People in Earlier Years Eat These Worms81

If these worms are prohibited, how can it be that so many generations succumbed to this prohibition, as Jews always ate these fish? The Gemarah82 says that Hashem does not bring takala (sin) to tzadikim. Tosafos83 says that this applies to prohibited food, since it is a disgrace for a talmid chacham to eat a davar issur.

Some argue that the anisakis is more common today. In addition, some wish to say that the anisakis infestation is due to the massive shipping of fish. In previous days, fish were caught in the river, brought home, cleaned out and cooked. Today, fish are routinely shipped to markets at a great distance from their origin. Fish often get shipped with the stomach intact and this allows the anisakis to go from the stomach into the flesh.84

However, we have already noted that it is not logical to say that the worm is more common now than in the past. In addition, today’s cleaning procedures is the same as in earlier years.85 Finally, the increase in anisakis is not in the frequency of anisakis, but in the increase of reported calls regarding reactions to eating the worm.86

Grows in a Non-kosher Fish

Those who wish to be stringent argue that the anisakis grows in the body of a non-kosher fish such as the krill, and are large enough to be visible when the salmon eats them.87 There is no conclusive proof for this point. In addition, the worms might grow from the excrement of the krill as well. The Chavos Daas88 says we do not say the concept of ”whatever comes out of a tamei is tamei” to non-kosher fish.

Eating a Worm When Eating Fish

Even according to the lenient opinion, it still is questionable whether one may use a fork to eat the fish, as the worm might be removed from the fish while he eats. Is this still considered “part of the fish”?

Some poskim say that the worms are permitted even after they are removed from the fish.89 Others only permit them if they are mixed with other items.90 However, others prohibit this as well.91

Obviously, one should remove a worm if he sees it, since it is “bal tishaksu.”92

Checking Fish

Those who wish to check fish for these worms may not remove the skin without having a mashgiach present (unless it is salmon) since the fish cannot be identified without the skin.93 Even with a light box, some reports indicate that only 7-10 percent of the worms are found using this method.94

Canned Fish – Cooking Fish

If one forbids fish with the anisakis worm, then canned fish are questionable, as the worms might enter the water during the cooking process.95 One suggestion is to boil the water before placing the fish in the pot, as the boiling water will kill the worms before they have a chance to enter the water.

If worms enter the water from the skin during the cooking process, one should consult with his rav.96

Health Concerns

There is a known health concern from eating an uncooked anisakis worm. This is known in the medical field as anisakiasis. Please refer to the footnote for references.97


Among those who permit98 fish which contain the anisakis worm are Harav Yisroel Belsky Shlita,99 Harav Falk Shlita and other Rabbonim. Harav Vaye Shlita (who has spent twenty-five plus years on the topic of worms and insects in fruits, vegetables, fish etc) is also lenient.100 Other poskim and kashrus organizations prohibit the fish. One should consult with his rav.

I would like to thank Rabbi Gedalya Oberlander Shlita from the Ohr Yisroel journal for providing me with all the Ohr Yisroel journals that cover this topic from many different Rabbonim. Thank you to Rabbi Yehuda Spitz Shlita for his help with this article. Thanks are due to Rabbi Yosef Blumenberg Shlita from the Tartikov Kollel who has provided me with many of the scientific works quoted in this issue.

1. The following are some of the Rabbonim who signed on the kol koreh: Harav Elyashiv Shlita, Harav Shternbuch Shlita, Harav Nissin Korelitz Shlita, Harav Wosner Shlita (Yated – Hebrew -13 Iyar 5770), see opinion of Harav Wosner Shlita quoted in Ohr Yisroel 56 page 51. However, refer to Hameasef (journal) 110:page 114 where Harav Vaye Shlita quotes Harav Wosner Shlita as holding “leaning towards” correct to be machmir not that it is ossur. The same is quoted in the name of Harav Chaim Kanievesky Shlita and Harav Nissin Korelitz Shlita. Refer to Solas Shani 2:pages 210-211.

2. This is the complete list: Butterfish, Cod -Scrod, Hake, Flounder -Yellow Tail, Wild Dabs, Black Backs, Turbot, Yellow Fin, Sole, Halibut, Pollack – Alaskan – Fillet fish sticks or patties, Red Perch, Red Snapper -Pacific Sable a.k.a Black Cod -including Smoked, Salmon, Wild -Fresh/Frozen/(some say canned) – All types Sardines – Norway, Scotland, Sole, Yellow Fin Sole. Refer to Ohr Yisroel 54:pages 64-65, 56:pages 49-50, also see Tenuvas Sadeh 72-75 pages 47-53, Hechsheiros 2:pages 472-485. See http://star-k.org/cons-vegdetail.php?ID=74.

3. Such as The Eda Hachareidis, and Rav Landau Shlita in Eretz Yisroel (Ohr Yisroel 56 page 152), Vaad of Flatbush, Star-K (http://star-k.org/cons-vegdetail.php?ID=74), and a few others. Some of them check the problematic fish and remove the worms.

4. As stated by Harav Vaye Shlita in Hameasef 110:page 115.

5. Teshuvas from Harav Yisroel Belsky Shlita and Harav Moshe Vaye Shlita (the teshuvos are available at http://www.theyeshivaworld.com).

6. There was a question regarding sable in 1978 and the poskim permitted it then (such as Harav Moshe Feinstein zt”l, the author of the Minchas Yitzchok and many others, as per Harav Meisels Shlita (06-01-10) given at the OU, see Mishnah Shlomo 1:31, Ohr Yisroel 6:page 218). Refer to Ohr Yisroel 6:pages 137-250 in great depth about a question which arose in the 90’s about worms in fish. A teshuva from Harav Falk Shlita was written on this around 20 years ago.

7. Refer to Vayikra 11:41, 44, 45.

8. Meseches Maakos 16b.

9. Y.D. 84:53.

10. Meseches Chullin 67b.

11. Rashi Meseches Chullin 67b “darna”. The Darchei Teshuva Y.D. 84:184 says in order for it to be considered found between the flesh and the skin it has to be found under the bottom layer of skin of the fish not on the layer which is directly beneath the scales.

12. Rashi Meseches Chullin 67b “minah”.

13. Meseches Chullin ibid.

14. Y.D. 84:16.

15. The kukyanei worm is a worm which is mentioned in the Gemarah as a kind of worm that is found in the intestines (Refer to Meseches Berochos 36a, Rashi “kukyanei”, Meseches Shabbos 109b).

16. Ohr Zeruah 1:437, Ran Meseches Chullin 67b, Taz Y.D. 84:21. See Sichas Chullin 67b. It is found in the liver and the lungs of the fish (Refer to Tosafos Meseches Chullin ibid “kukyanei”, Rashba Meseches Chullin ibid, Rosh 3:69, Taz 21, Pri Chadash 84:45, Kaf Hachaim 84:147. Rashi “kukyanei” seems to be talking about an animal. Although Rashi would agree that if the worm is found in the inner section of the fish it would be forbidden (Bais Yosef Y.D. 84:16).

17. Sifsei Daas Y.D. 84:43-44. Refer to Darchei Teshuva Y.D. 84:180.

18. Issur V’heter 41:9.

19. Meseches Chullin 67b. See Rosh Chullin 3:69.

20. Ohr Zeruah 1:437, Ran Meseches Chullin 67b, Meiri Meseches Chullin 67b, Hago’es Ashri Meseches Chullin 3:69, Taz 84:21, Pri Megadim 84:43. See Yam Shel Shlomo Meseches Chullin 3:104. Refer to Ohr Yisroel 54:pages 43-44.

21. Teshuva from Harav Yisroel Belsky Shlita.

22. Rosh Meseches Chullin 3:69, Bais Yosef Y.D. 64, Shulchan Aruch 84:16, Taz 21, Shach 43, Levush 16, Aruch Hashulchan 89.

23. Hilchos Machalas Asuros 2:17. Refer to Ohr Yisroel 54 pages 20-21.

24. As expressed by all the poskim (see Ohr Yisroel 6:page 204).

25. The Maggid Mishnah (Machalas Asuros ibid) holds that the Gemarah is talking about a worm which grew in the fish after the fish died and is permitted. However, a worm which is found during the life time of the fish is forbidden because maybe it came from the outside.

26. 47:1:pages 49-50 (new). Refer to V’anochi Solas Hosafos page 6 on this Hag’oes to the Sharei Dura.

27. Teshuva from Harav Yisroel Belsky Shlita.

28. Teshuva from Harav Falk Shlita on this topic.

29. Refer to Ohr Yisroel 54:pages 27-33, and pages 34-41. See Solas Shani 2:pages 199-212, Tenuvas Sadeh 21-25 pages 21-31, Divrei Pinchas 48. See Solas Shani 199-212. Refer to Shevet Halevi 4:83, 7:127, M’Bais Levi 17:pages 97:footnote 30.

30. Ohr Yisroel 54:page 61. Harav Yisroel Belsky Shlita maintains Chazal did not give conditions to the heter in Shulchan Aruch Y.D. 84:16.

31. Teshuva from Harav Yisrael Belsky Shlita. Refer to Meseches Shabbos 54b, 75a, 102b. See Ohr Yisrael 54:page 37. See Aruch on Aruch Daran.

32. Ohr Yisroel 54:pages 43-44. See Kenesses Hagedolah Y.D. 84:101.

33. 38:28. Refer to Darchei Teshuva 84:184, Chazzon Ish Y.D. 14:6, Ohr Yisroel 6:pages 176-177.

34. http://www.dpd.cdc.gov/dpdx/HTML/Anisakiasis.htm

35. http://www.dpd.cdc.gov/dpdx/HTML/Anisakiasis.htm. http://en.wikipedia.org/wiki/Anisakis. Many times scientists can make mistakes as well (Shevet Halevi 4:83, see M’Bais Levi 17:page 97: footnote 30, also see Ohr Yisroel 54:pages 49-53). Refer to European Food Safety Authority Journal 2010 8(4):1543:pages12-13.

36. To see pictures of this worm go to www.hamachon.co.il.

37. Refer to Ohr Yisroel 54:pages 49-50, 56:page 53 quoting the opinion of Harav Revach Shlita.

38. Ohr Yisroel 56:page 48.

39. Ohr Yisroel 56:pages 52-53. Refer ibid pages 53-54 to other reasons why the anisakis may be more common today in the flesh of the fish.

40. Refer to American Microspocial Society April 1986 95:2 (OU handout 06-01-10), teshuva from Harav Yisroel Belsky Shlita. Refer to Shulchan Govah Y.D. 84:51, Kitzur Shulchan Aruch 46:43, Ohr Yisroel 6:page 187.

41. http://en.wikipedia.org/wiki/Anisakis, http://www.ncbi.nlm.nih.gov/pubmed/18400801.

42. Some indications of this is that they claim it is mostly found in the organs of the stomach and less often in the flesh. Other times they were found while penetrating the flesh with the worm partially in the stomach. Refer to Ohr Yisroel 54:pages 54 and 64, 56:pages 52-56, 58:pages 146-152, also see Ohr Yisroel 6 pages 242-244, Lehoros Nosson 9:23-25, V’anochi Solas pages 5-8, Vayan Dovid 1:114, teshuva from Rabbi Bess Shlita (Los Angeles), www. hamachon.co.il.

43. As per teshuva of Harav Yisroel Belsky Shlita, also see Ohr Yisroel 6:page 216. This is the opinion of Harav Falk Shlita as well in a teshuva dated on Erev Shabbos Parshas Bamidbar 5770. Also refer to Rama Y.D. 84:16 who says if the worm is going in and out of the place where it is found in the fish it is permitted (see Divrei Chamudos Meseches Chullin 3:368).

44. European Food Safety Authority (EFSA) Journal 2010; 8(4):1543 page 14.

45. Refer to Ohr Yisroel 57:pages 149-150.

46. Regarding the topic of Torah and Science see the following books on this subject: Torah and Science (Levi) pages 139-157, In the Beginning (Ktav 1990), Challenge: Torah Views and Science and its Problems, The Age of the Universe (Rabbi Aryeh Kaplan), The Heavenly Time Machine, Fossils and Faith: Understanding Torah and Science, The Science in Torah, The Challenge of Creation, Halakah and Scientific Method (www.yutorah.org), Rashbas Attitude Towards Science and its Limits (Torah U’Madda Journal (January 1992 pages 52-81 in great depth). In regard to Rabbis consulting (and/or relying on) scientific experts see Meseches Chullin 77a, Avodah Zarah 28a, Niddah 22b, Sanhedrin 33a, Maharik Shoresh 159, Shevus Yaakov 1:65, Chacham Tzvi 74-78, Pleisi Y.D. 40:4. Regarding Chazals knowledge of science and refuahs (medicine) see Meseches Pesachim 94b, Bava Metziah 83b, Teshuvos Hageonim (Harkaby) 394:page 208 old, Moreh Nevuchim 2:8, 3:14, Rambam Hilchos Kiddush Hachodesh 9:1, 17:24, Aruch Hashulchan E.H, 13:30, Asei Lecha Rav 5:49, Tzitz Eliezer 19:29. Regarding what halacha viewed as a wound which one can not recover and what the Torah has to say about it, see Rambam Hilchos Gerushin 13:16, Rambam Hilchos Rotzeach 2:8. Chazzon Ish E.H. 27:3. Regarding sunrise, sun set and ben hashmoshes how it relates the moving of the sun, see Meseches Pesachim 94a, for many other sources see www.yasharbooks.com/open. There was also a discussion regarding treifos and science. Refer to Meseches Chullin 42a, 46a, Rambam Hilchos Shechitah 10:12-13, Plesi Y.D. 40:4, Yad Yehuda Y.D. 30:3, Rivash 447, Rashba 1:98, Yam Shel Shlomo Chullin 3:80, Shach Y.D. 57:48, Bechor Shor 58a, Igros Moshe C.M. 2:73:4:page 308, Chazzon Ish Y.D. 5:3. For a detailed explanation of how to reconcile science and Torah see Michtav M’eliyahu 4:page 113, www.yasharbooks.com/open. Refer to Meseches Shabbos 135a where it states a baby born in the eight month can not survive and one can not save its life. On this also see Ritvah Yevamos 80b (Harav Kook pages 978-982), Shulchan Aruch O.C. 330:7-8, Y.D. 266:11, Rivash 446-447, Minchas Yitzchok 4:123-19-20, Chaazon Ish Y.D. 155:4. Refer to www.yasharbooks.com/open. For other examples see http://www.aishdas.org/toratemet/science.html.

47. Refer to Rambam Sefer Hamitzvhas Lo Sasei 179, and Moreh Nevuchim 1:72.

48. Refer to Rashi Meseches Chullin 67b “minah”. Refer to Tosafos Meseches Chullin ibid “l’rabos”. See Kovetz Bais Aron V’Yisroel 75:page 83.

49. Meseches Shabbos 12a, 107b, Rambam Hilchos Shabbos 11:2, Shulchan Aruch O.C. 316:9, Levush 9, Eishel Avraham Butchatch on 327 (kama), Ben Ish Chai Vaeira 2:13, Yufei Leleiv 316:1, Lev Chaim 3:17 (end), Mekor Chaim 316:9, Mishnah Berurah 41, Kaf Hachaim 82, Yalkut Yosef 4:pages 546-548, opinion of the Chazzon Ish zt”l quoted in Birur Halacha 316:page 250. However see ibid page 251 who says that Harav Chaim Kanievesky Shlita did not hear the above mentioned pesak of the Chazzon Ish zt”l. Harav Chaim Kanievesky Shlita is lenient in the above as well (see Am Mekadshei Shvi’i 2:page 40:29 and page 180:21). Opinion of the Chazzon Ish zt”l and Harav Shlomo Zalman Aurbach zt”l quoted in Shalmei Nissin (Shabos, Haoreg) pages 161-162. Refer to Birchos Yitzchok 316:pages 382-383 and Rivevos Ephraim 6:458:18. See Chiddushei Basra on Mishnah Berurah 316 and Oz Nedberu 1:79 page 162:117, Bris Olom page 85:11, Tzitz Eliezer 19:29 meluim pages 180-181, Toras Hamelochos Tzad pages 107-108, Minchas Ish page 466:footnote 51 quoting the opinion of Harav Nissin Korelitz Shlita as being lenient. Alos refer to Hishtanus Hativim B’halacha pages 182-184. Regarding other areas which speak about items creating from dirt such as a mouse, see Meseches Chullin 126b, Sanhedrin 91a, Rashi Meseches Chullin ibid “yeish”, Tiferes Yisroel Meseches Chullin 9 Boaz 2, Perush Hamishnayos Rambam to Chullin 9, Ohr Yisroel 6:pages 225-226. See Aprakasisa Deyana 1:20 who speaks about this as well.

50. Refer to footnote ibid, and Ritvah, Rashba, and Ramban on Meseches Shabbos 12a. Also see Biur Halacha 316 “l’harga”.

51. Teshuva From Harav Falk on this topic. Refer to Michtav M’Eliyahu 4:page 355-356 in footnote. See Ohr Yisroel 6:pages 213-214.

52. Dor Revi’i Meseches Chullin introduction page 8 (old), see Yabea Omer Y.D. 10:24, opinion of Harav Zalman Nechemia Goldberg Shlita quoted in (Hishtanus Hativim B’halacha page 286:51, opinion of Harav Herschel Schachter Shlita. See http://www.aishdas.org/toratemet/science.html, www.yasharbooks.com/open. Maybe this is why Ravina (mentioned in the Gemarah in Meseches Chullin 67b) ate the worm in the fish, since he knows people would want to be stringent because science may have a different view than the Torah and perhaps we should follow science. To prove this is not so, he ate the worm to show it is permitted (Ohr Yisroel 6:pages 165 and 211).

53. Pachad Yitzchok (Lampronti) tzeidah pages 31-22, Teshuvos Hageonim Sharei Teshuva 225:page 22, Shevet Hakehasi 3:126, Ashrei Ish 2:page 265. Refer to Birur Halacha (Zilber) 316:pages 250-252. Others quote Harav Shlomo Zalman Aurbach zt”l and Harav Elyashiv Shlita as saying “it is better” to refrain from killing them on Shabbos (Orchos Shabbos 1:page 426:footnote 47). See Chut Shani Shabbos 1:page 125 who is unsure. Refer to Menuchas Ahavah 3:18:Mei Menuchos 13, also Meluim ibid 3:18:6. See Toras Shabbos 316:15.

54. Refer to Ohr Yisroel 6:pages 24-25.

55. Ohr Yisroel 54:page 52.

56. Included are Harav Moshe Feinstein zt”l, Harav Shlomo Zalman Aurbach zt:”l, Harav Weiss zt”l (author of Minchas Yitzchak), Harav Elyashiv Shlita and Harav Chaim Kanievesky Shlita, see Plesi Y.D. 40:4, Kovetz Bais Aron V’Yisroel 75:page 85, Ohr Yisroel 6:page 136, pages 147-148, 155-156, 167-168, 201, and 235-236, Minchas Yitzchak 2:27. Refer to Mishnah Shlomo 1:31, Bedikas Hamazon K’halacha 1:page 110. See Rivash 45.

57. Opinion of Harav Herschel Schachter Shlita as related by Rabbi Ari Zahtz (email 05-26-10).

58. Lehoros Nosson 9:24:page 34. See Ohr Yisroel 54:page 54.

59. Ohr Yisroel 54:page 61.

60. Refer to Hishtanus Hativim B’halacha which is an entire sefer on the topic on “if times have changed”.

61. Refer to Ohr Yisroel 54:page 51. See Chazzon Ish Y.D. 14:8.

62. Refer to Tosafos Meseches Avodah Zarah 24b “para”, Rashba 98, Rama E.H. 156:4, see Ohr Yisroel 6:page 219.

63. Ohr Yisroel 6:page 219.

64. Refer to teshuvos on www.hamachon.co.il. However, see Ohr Yisroel 6:page 140.

65. As stated in the European Food Safety Authority (EFSA) Journal 2010; 8(4):1543 pages 16-17, http://www.onefish.org/servlet/CDSServlet?status=ND0zODE1OS50b3JsaWJJUEUzNDMwNCY2PWVuJjMzPWRvY3VtZW50cyYzNz1pbmZv , and as stated by Harav Vaye Shlita (OU meeting 06-01-10). Refer to International Journal for Parasitology 1975 pages 133-135, Journal of Food Protection 56(9) 783-787 (September 1993).

66. Refer to International Journal for Parasitology 1975 pages 133-135.

67. As per Harav Vaye Shlita (OU meeting 06-01-10), as well as teshuva from Harav Falk Shlita dated Erev Shabbos Parshas Bamidbar 5770, see opinion of Harav Yisroel Belsky Shlita as expressed in an OU memo dated 1-26-10.

68. Y.D. 84:36.

69. 91. Refer to Madrich Lebedikas Tolaim (Falk) pages 92-93.

70. Y.D. 2:146, E.H. 3:33.

71. Yechaveh Daas 6:47.

72. Refer to Darchei Teshuva Y.D. 84:45, Dovev Mesharim 1:1, Tuv Taam V’daas Tanina 53 (kuntres achron), Tlisa 1:160, Shevet Halevi 4:125:2, 7:2:10. See Sheilas Yaavetz 124, Yabea Omer Y.D. 4:20:2, 4:21:7, Beer Moshe 5:16, Ohr Yisroel 6:page 194, pages 227-228, V’anochi Solas pages 8-11. For an entire discussion on this topic refer to Kuntres Ayin Lo Rasa pages 22-30.

73. Refer to opinion of Harav Falk Shlita quoted in Bedikas Hamazon K’halacha 1:page 109. See ibid page 110 quoting the opinion of Harav Shlomo Zalman Aurbach zt”l, Harav Ben-zion Abba Shaul zt”l, Harav Fisher zt”l, and Harav Korelitz Shlita.

74. See Tiferes Yisroel Avodah Zarah 2:Boaz 3, Pleisi Y.D. 84:5, Darchei Teshuva 84:94, Shevet Halevi 7:122.

75. Machzei Eliyahu 91. See Igros Moshe Y.D. 2:146, E.H. 3:33. Refer to Ohr Yisroel 6, pages 227-228, 20:page 97.

76. Opinion of Harav Shlomo Zalman Aurbach zt”l, Harav Ben-zion Abba Shaul zt”l, Harav Nissin Korelitz Shlita (quoted in Ohr Yisroel 6:page 180), opinion of Harav Falk Shlita, opinion of Harav Yisroel Belsky Shlita, Harav Genack Shlita, and opinion of Harav Herschel Shachter Shlita quoted in OU document C-31, see Chazzon Ish Y.D. 14:8. Refer to Kuntres Ayin Lo Rasa pages 27-30.

77. Opinion of Harav Elyashiv Shlita quoted in teshuva of Rabbi Bess Shlita. Refer to Ohr Yisroel 54:page 40, Lehoros Nosson 9:25.

78. As explained by Harav Vaye Shlita (see Ohr Yisroel 56:page 43).

79. Teshuva from Harav Yisrael Belsky Shlita.

80. Ohr Yisroel 54:page 62.

81. Refer to Imrei Yosher 2:11.

82. Gittin 7a.

83. Meseches Gittin 7a “hashta.”

84. Refer to Ohr Yisroel 56:pages 54-55.

85. Opinion of Harav Yisroel Belsky Shlita as expressed in his teshuva on this topic. Also heard from Harav Vaye Shlita (OU meeting 06-01-10).

86. European Food Safety Authority (EFSA) Journal 2010; 8(4):1543 page 11. Refer to Marine Fish Parasites of Public Health Importance Robert E. Olson. Also see European Food Safety Authority (EFSA) Journal 2010; 8(4):1543 pages 46-47.

87. Expressed in the teshuva written by Rabbi Bess Shlita.

88. 61:1page 6b (old).

89. Ravyah 1093, Bais Yosef Y.D. 94, Rama, Issur V’heter 41:9. Refer to Mordechai Chullin 646.

90. Rama Y.D. 84:16.

91. Pri Chadash 84:53, Aruch Hashulchan 84:93.

92. Taz Y.D. 84:23, see Shevet Halevi 7:123:3, Ohr Yisroel 6:page 183.

93. Opinion of Harav Vaye Shlita (See Ohr Yisroel 56:page 43).

94. European Food Safety Authority (EFSA) Journal 2010; 8(4):1543 page 17, http://www.7isfp.com/pdf/workshop.pdf

95. Refer to Ohr Yisroel 54:pages 61-62. For reasoning see teshuva from Harav Yisroel Belsky Shlita.

96. Refer to Divrei Pinchas 48 who discusses some of the halachic background for this question.

97. http://www.fda.gov/Food/FoodSafety/FoodborneIllnessFoodborneIllnessFoodbornePathogensNaturalToxins/BadBugBook/ucm070768.htm, see Journal of Wildlife Diseases Vol 25 No 3 July 1989, http://www.parasitesinhumans.org/anisakis.html.

98. Refer to footnote 1 where others were lenient when asked by Harav Vaye Shlita.

99. For a link to the teshuva see http://matzav.com/rav-belskys-stance-on-the-kashrus-of-worms-in-flesh-of-fish#comment-49286

100. Expressed in OU (06-01-10), and in Hameasef 110:page 115. For the view of Harav Shlomo Miller Shlita, see http://matzav.com/letter-from-rav-shlomo-miller-regarding-bugs-in-fish.

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