The difference between the Yerushalmi and the Bavli maybe be accounted for as follows:
- Chilazon is a general term in Aramaic that means “snail”.
See the Arukh:
חלזון [שנעקע] (פרק יב דכליים) או שקשר חלזון בראשה טמאה פי' זה הוא
צורתו ונקרא חלזון כמו החלזון שהוא מוקף (א"ב בעל הערוך צייר בספרו צורת
חלזון וכן עשה בקרדום שניטל עושפו עיין ערך בקע ג'):
חִלָּזוֹן m.n. PBH 1 conchiferous animal, snail, Gastropoda (zoology).
2 cataract of the eye. 3 a snail-shaped ring. [Together with Aram.
חִלֽזוֹנָא, Syr. חָלְזוֹנָא, whence prob. Arab. ḥalazūn (= snail), of
unknown origin.] Derivatives: חלזן, חֶלְזוֹנִי.
Many rishonim identify the chilazon as a snail, as seen here:
• Rambam in the Perush Al HaMishnah (Keilim 12:1)
חלזון- והוא כעין צדף עשוי מברזל נועלים בו את הדלתות, ואותו הצדף הוא
צדף של בעל חי הימי הנקרא חלזון
Chilazon - It is like a shell made of iron, like the shell of the sea
creature that is called Chalzun in Arabic (snail).
• Rabbeinu Gershom (Berachot 38b), Rashi (Avodah Zarah 28b)
״חלזון קורים בלע״ז לימץ״
“The chilazon is called in foreign language, limace (Old French for
לימ״ץ בלע״ז מין חלזון
“Limace (Old French for snail) in a foreign language is a kind of
• Chochmat Shlomo (Shabbat 77b)
שבלול לימצא נ״ב הוא פי׳ של חומט רש״י פי׳ שבלול חומט שקורים בל״א שנע״ק
Shablul is a limace (Old French for snail) and it is the meaning of
Rashi explained Shablul as Chomet which is called in another language
schnecke (snail in Yiddish).
• Radak (Hullin 132a)
שבלול הוא שרץ הנקרא בלעז לימס״א,ויש אומרים קראקו״ל…שבלול שהוא מתכסה
בתוך קליפתו שהיא לו כמו לבוש
Shablul is a sheretz which is called limace (Old French for snail) in
a foreign language, and there is who call it “caragol” (snail in
Spanish)… The Shablul hides itself inside his shell which is like a
- When the sea snail ‘goes up from the sea once in seventy years’ by being washed ashore by a storm and it is inside its shell or the land snail has sealed itself inside to prevent moist lost during long periods of rain (as known, land snails only move during rain or short after it has rained), then one is not liable for tzad as the snail is already self-caught or unable to move as it went inside its shell.
Furthermore, the Tanna of the Yerushalmi implies the chilazon is not liable for tzad if it is like the tachash that was brought by Hashem to the desert to make the mishkan. This is because is easily available.
Nevertheless, there is melacha of tzad for a chilazon when the chilazon is able to move, even with reduced mobility mentioned by Rashi in Chagiga 11a (see Rashi in Shabbat 106 and 107 where even worms are liable for tzeida). This applies to when the sea snail is in the water or for land snails on land.
Therefore, the Yerushalmi’s lonely opinion and the Bavli are discussing two different situations in one situation one is liable for trapping (when the snail is able to move, even if slowly) and in the other situation, one is not liable for trapping (when the snail is immobile and easily available).