Does the Murex snail have גידים ועצמות as described in the Yerushalmi?

Snails are definitely considered by Chazal to possess .גידים ועצמות  This can be shown from several independent sources:

1) Chazal tell us that only creatures that have bones can live longer than 6 or 12 months182. Since many snails live longer than 12 months183, they must fall into Chazal’s definition of possessing גידים ועצמות – “ligaments and bones”.

2) The ספרא (cited in the גמרא חולין ) states that all שרצים have גידים 184 ועצמות . The חומט is one of the eight שרצים mentioned in the Torah. Numerous ראשונים translate the חומט as a snail (see discussion on page 17).

Hence, we must explain how a snail is considered by Chazal to have גידים ועצמות , despite the fact that snails do not have actual bones in the common definition of the term. (This explanation is necessary regardless of the identity of the חלזון of תכלת . It is a question of
explaining the statement of Chazal. As such, it is only discussed here since it has been raised by others as if it is a question related to – תכלת though it is not.)

One possibility may be that the shell is viewed as “bones”, in the sense that it serves a similar protective purpose as bones. As איוב states: וּבַׁעֲצָמוֹת וְּגִּידִּים תְּסֹכְּכֵנִּי – “with bones and  ligaments you have shielded me”185. Snails also have a ligament/muscle that attaches them to their shell (known as the columellar muscle) which can be considered גידים . (See photo on last page.)

The Yerushalmi discusses whether a חלזון possesses – גידים ועצמות “ligaments and bones”. To prove this, it was not sufficient to the Yerushalmi to simply examine a חלזון to determine if it had גידים ועצמות . Rather, they cite the fact that creatures that live longer than 6 months must possess גידים ועצמות . This discussion would seem to indicate that we are speaking about a creature that does not have literal “bones” that would be clearly apparent, but rather has some feature that can also be included in this term (such as the shell of a
snail). If it were referring to a creature that has literal bones (according to the simple understanding), there would not be room for debating this point at all – simple observation would have sufficed 186. Hence, this discussion in Yerushalmi further supports the fact that the חלזון is a snail.