Hekte

Kyzikos, situated on the Propontis, built much of its commercial power on electrum coinage mined and refined in the region — these hektes circulated as trusted trading currency across the Greek world precisely because Kyzikene electrum had a reputation for consistent alloy quality at a time when other issuers routinely debased. The city maintained effective control over this standard for well over a century, an unusually long run of monetary discipline for any ancient polis.

The tuna on the reverse — present on virtually every Kyzikene issue regardless of the changing obverse type — functioned as a civic guarantee mark, not merely decoration.