Wien Cod. 13647

[Jorge_Stolfi]

You are not allowed to view links. Register or Login to view. cites some myths that explain why there are two fish [in Pisces], but not where the idea of a cord came from.

I thought it simply came from how the constellation looks.

Objectively, constellations don't look like anything.  A few groups of stars may strongly suggest particular interpretations, like the Southern Cross, or may at least look like they belong together, like the Pleiades and Orion's belt. But in general the division of the stars into constellations, and their interpretation as animals people etc were quite arbitrary.  Proofis that each culture divided the stars into different constellations with very different interpretations.

I don't think that someone would have seen the stars of Pisces as belonging together, much less as being two fishes connected by a rope, if there was not some legend that provided that interpretation.

At some point, people started depicting the fish in parallel as well, keeping the tether and stars within that new shape. And sometimes it was just the tether.

I suppose that the compact layout was mandated by the space available for each sign in Zodiac charts.  

All the best, --stolfi