Its name derives from the Polish weapon it resembles. It is also known as northern or crocodile fish, since its head is similar to that of the animal. These fish live in brackish and sweet waters. They are able to develop movements to start swimming very fast causing small bursts of swimming that make their prey afraid of their unpredictable movements. These outbursts use them both to hunt and to defend themselves against possible threats. The average size is about 50 cms and 1 m and a weight up to 25 kgs. This species was introduced in the 50s by the Administration for sport fishing, and has been moved to many places in the peninsula. They eat fish of all species and crabs. It is usually fished in winter.