Potamon fluviatile, an unassuming freshwater crab, has shown superior staying power, thriving in the canals built by the Etruscans nearly 3,000 years ago, Italian zoologists say.

• 淡水蟹这种不起眼的螃蟹，竟然展现了优越的持久力，能够在伊特鲁里亚人3000年前建造的运河里生存至今，义大利动物学家说。