Coastguards in the coastal town of Barmouth on the West Wales coast have issued a warning to bathers to look out for weaver fish.
According to icNorthWales, the warnings came after a 24-year tourist was stung by one of the venomous fish while paddling in the waters of Barmouth beach. The man, who could not speak English, was reportedly screaming in agony.
A spokesman for the coastguards told icNorthWales: "In one way or another, an officer managed to get the message across to him that he had been stung by a fish which lives in the sand.
"When we saw the mark on his foot we realised it was a weaver fish and arranged medical treatment on the spot."
The Lesser weaver, which grows to around 10-15cm, spends most of its time in shallow water over sandy areas. It sometimes enters shallow water in large numbers during the summer months.