BRITISH FRESH-WATER FISHES 



also stated to partake of insects and worms. The 

 manner of propulsion through the water reminds one of 

 the movements of an Eel, and like that fish, the present 

 species and its cousin to follow, are very tenacious, and 

 will live for quite a long period out of their native 

 element. In olden days a dish of Lampreys was con- 

 sidered a great delicacy, but to-day this interesting 

 tenant of our rivers is mostlv used as bait for other 

 fishes. 



Brook, or Planer's Lamprey. — Lampetra planeri (Fig. 

 30). The larval form of the Lamprey is known as the 

 Pride. It has no teeth, but on the front of the mouth 

 there is a fringe of barbules which serves the purpose of a 

 sieve for sifting food. It resides in a tube, and although 

 open at one end, the inhabitant works its way further in 

 if danger threatens. This larval state of existence lasts 

 for three or four years, and it is not until the creature 

 has attained a length of several inches that the adult 

 form is reached. 



Planer's Lamprey does not grow to a greater length 

 than 8 inches, and haunts smaller streams than Lampetra 

 fiuviatilis. Moreover, it restricts itself entirely to fresh 

 water, and does not migrate to the sea. It is well 

 distributed in our smaller waterways, and extends to 

 Scotland, and is common in Ireland. 



In general appearance this second species (there is a 



third species, the Sea Lamprey, Petromyzon marinus, 



which enters fresh water to spawn, and is a much larger 



fish, attaining a maximum length of 36 inches), is dis- 

 62 



