Fossilized remains of a fish supper have revealed a hitherto unknown Roman trade route. Genetic analysis shows that 1400-year-old catfish unearthed in an ancient Anatolian city probably came from Egypt1.
The fossils were found among the mountain-top ruins at Sagalassos, 110 kilometres inland from Turkey's southern Mediterranean coast. Catfish (Clarias gariepinus) are not native this region.
In AD600 Sagalassos was a hub of Greco-Roman culture, agriculture and export. "The catfish was probably a delicacy for aristocrats," says the director of the dig Marc Waelkens from the Catholic University of Leuven, Belgium. Romans may also have imported these and other exotic fish to stock their decorative pools. Waelkens and his colleagues found Nile perch (Lates niloticus) and African tilapia (Tilapia zillii) at the site too, they report in this month's Journal of Archaeological Science .
The fish add to growing evidence that Sagalassos had connections with far-flung regions of the Roman Empire - its pottery, for example, has turned up in north-east Africa.
It's interesting that trade relationships were going on this late, says Stephen Mitchell, who studies ancient history at the University of Exeter. From AD500 onwards, the city suffered earthquakes, economic recession, plague and invasion. Evidence of fish importing, he says, "implies a high level of organisation close to the city's end".
Head start
Waelkens' team found the fish remains in kitchen rubbish pits. The presence of fins, but no heads, was the first hint that they were from afar. Says fish geneticist Filip Volckaert, also from the University of Leuven: "Egyptians probably opened up the belly, took out the guts, took off the heads, treated them with salt or dried them, and then put them on a shipment." Sun drying might also have helped preserve the fishes' DNA.
The researchers analysed mitochondrial DNA from six of the pectoral fins. This genetic material changes little over time. They compared it against modern specimens from Turkey, Syria, Israel, Mali, Egypt and Senegal. The Sagalassos samples matched those from present-day catfish from the river Nile.
Since 1990, Sagalassos has become a large-scale, interdisciplinary excavation. Covering 1800 square kilometers, the area reveals a near intact city and its contents. Researchers are reconstructing the life style, economy, agricultural practices and climate changes experienced in this late Roman outpost.
