A primitive group lacking jaws, fin rays and scales. There are 4 European species

Fish with a cartilaginous skeleton and  a skin covered with dermal denticles. There are 15 species living in inshore waters.

Fish with a cartilaginous skeleton and  a skin covered with dermal denticles, rather like sharks but with flattened bodies. There are 20 species living in inshore waters.

Elongate fish with a single fin running from the dorsal to anal sides. 4 species live in shallow European waters.

Fast swimming, open water fish with large scales and no lateral line. Including the anchovy there are 6 European species.

Generally quite large fish with a small adipose fin. A lateral line is present. 7 species of salmon, 6 whitefish, 1 grayling, 2 smelts, 2 argentines and 1 pike and  are found in Europe .

One of the most important groups of freshwater fish.There is a single dorsal fin, no adipose fin and they may have barbels. There are about 35 species in N. Europe.

The wels is probably the largest freshwater fish in Europe and the only native catfish. Two species of American Ictaluridae have been introduced. Catfish carry barbels around the mouth.

Generally marine fish which favour cold waters. The fins lack spines, usually with 2 or 3 dorsal fins, 1 or 2 anal fins and a barbel on the chin.About 30 species live in Northern Europe.

This group includes flying fish, garfish and sand smelts. The sand smelts are the most likely to be seen as they live close inshore including brackish water lagoons. They have large scales and 2 dorsal fins. There are probably 2 species of sand smelt in N. Europe.

There are only a few representitives of this order in N. Europe. All have laterally compressed bodies with  a large head and a protrusible mouth.

A commonly caught group in both fresh  and sea water. There are 3 species of stickleback, 1 snipefish and 8 pipefish and sea horses in N. Europe.

An abundant and diverse group of mostly benthic fish

Common, typically predatory fish with spiny fins.

Flattened fish adapted to hide on the sea bed. About 22 species are found in marine waters in N. Europe. Only the flounder normally enters freshwater.

This group is normally tropical. A few sunfish are caught inshore. Much more abundant in European waters is the trigger fish Balistes carolinensis. In the last few years, perhaps linked to global warming it has extended its range around Britain.