The story of bugs in fish, is a fascinating one. Rabbis differ on the issue, depending on their understanding of the nature of Talmud and the Oral Torah. I have already written in another series, that there are those who regard Talmud as a revealed text; always infallible and true. Others regard Talmud as the main repository of the Oral tradition regarding halachah, but the Aggadah (narrative parts) are primarily allegory, legend, or, in the case of scientific and medical information, simply the best knowledge of the day. This has been a source of contention since at least the early tenth century. But what do we do if a halachah is based on such a "scientific" concept, which is now known to be untrue? The Talmud states that there are two types of parasites that invade fish. One is aquatic creatures that the fish have ingested. Whether these creatures are alive or dead, they remain forbidden to eat. The other type is creatures, especially worms, that form in parts of the fish that are decaying because of an illness. Bugs formed by spontaneous generation are not considered to be true bugs, and, in the case of bugs found in the flesh of fish, they are completely kosher. This has been the accepted halachah for at least 1800 years. Faced with the undeniable fact that there is no such thing as spontaneous generation, rabbis have had to deal with this issue. Many of the more conservative(small "c") rabbis have said "No! Science is wrong! Since it is said in the Talmud, spontaneous generation is the truth, science is a lie". The first rabbis I studied under took this approach. An alternative view, close to the first, but with a different conclusion, is that "things have changed. The bugs that were produced by spontaneous generation were real, but are now extinct. The ones we see now are new ones (evolution?), and are therefore forbidden to eat." Some right wing rabbis therefore forbid worms in fish flesh, which is actually a departure from the Talmud and normative halachah. A third view, which is the most widely accepted, is that although the worms and other parasites that we find in fish are not from spontaneous generation, but nevertheless hatched in the fish, and are therefore to be considered part of the fish, and hence kosher. This is the policy of the OU, and most other kashrut agencies. However, there are some rabbis within the OU who are pushing for a ban on these bugs, as the concept upon which the leniency was built, is now known to be erroneous. Their view is that newly discovered facts can, indeed, change a long accepted halachah. This view is being considered by halachic authorities, but few have been so bold as taking upon themselves such a revolutionary idea. In practice, however, these parasites should not be a problem unless seen. Like most common problems that exist in the kashrut area, if they do not constitute a majority of the cases, we are not required to look for them. In addition, we would have to see if these parasites remain intact after cooking. In this regard, sushi, made as it is from raw fish, is, theoretically more problematic. But even there, most are lenient. This issue of scientific concepts challenging traditional ones, has many applications in other halachic areas as well. In the absence of a Sanhedrin, it will take a long time to resolve them. One more hotly debated topic is bugs, as well as other forbidden items that have undergone a fundamental transformation. I will go further into that question in my next post. However, it has been known since almost forever, that figs are pollinated by a species of wasp that then dies inside the fig. By the time the fig comes to you, it has been digested by enzymes in the fruit. Occasionally, you can detect an outline of the late wasp. There is absolutely no question that the wasp is no longer an insect of halachic concern. Nevertheless, I have seen many warnings about the fig wasp over the last few years. I suspect a new stringency is now hatching. Once the consumer is concerned, the kashrut industry, seeking to please the customer, will often arrive at far reaching conclusions, well beyond the boundaries of halachah..