424 THE FRESH-WATER FISHES OF EUROPE. 



while spawning. According to Yarrell, the spawn escapes in both sexes by 

 a membranous sheath, which is prolonged beyond the apertures of the body. 

 It is deposited in the excavated grooves and covered with sand. After 

 spawning the fish is exhausted, and goes down to the sea. Its flesh is well- 

 flavoured; but some peoples have a prejudice against it. It is not com- 

 monly eaten by the inhabitants of Scotland, Ireland, or Cornwall. Pennant 

 considered it best in March, April, and May, when the flesh is firmer than at 

 other times. 



Petromyzon fluviatilis (LINNJEUS). The Lampern. 



The River Lamprey, or Lampern of English writers, is known in Ger- 

 many as Flussneunauge. In Austria it is not always distinguished from the 

 P. marinus, being popularly known either as Pricke or Neunauge. The Italians 

 term \iLampredone, and the Swedes Nejnoga. Its distribution is very similar 

 to that of the Sea Lamprey, but, besides ranging over the other parts of 

 Europe, it is also distributed in Russia ; and, in North America, ranges up to 

 Alaska. A variety of the species is found in Japan. 



In English rivers, especially the Severn, Trent, and Thames, the Lampern 



Fig. 207. PETROMTZON FLUVIATILIS 



was formerly a not unimportant article of local commerce. Pennant states that 

 in his time vast quantities were taken about Mortlake; and that the Dutch 

 purchased them for bait for the Cod fishery, taking 450,000 in a season, at 

 forty shillings a thousand ; and he states that about 100,000 a year were 

 sent to Harwich to be used as bait. The number in the Thames is now much 

 diminished. Buckland agrees in regarding Lamperns as the best possible bait 

 for Cod ; and states that a considerable trade is carried on in the Trent, in 

 catching them as bait for the deep-sea fisheries. The Lampern fishery goes on 

 from the end of August till March ; 3,000 have been taken at Newark in one 

 night. When captured they are sent in wicker baskets to the fishing ports 

 on the east coast, but must be kept moving while in transit to avoid suffoca- 

 tion. Their value for bait is partly owing to the fish being very tenacious of 

 life. The Dutch fishermen manage to keep them alive for weeks, and use 

 them in the Turbot fishery. 



The Lampern feeds on worms, insects, and their larvae, small fishes, and 



