41 



Lamperns were only taken four or five times in ray presence 

 with the „kwakkuil"; they were ouly single and sraall speci- 

 mens; a regular fishiug of lamperus for the lines ofour cod-fisher- 

 men, such as is practised on our rivers and also, though in a lesser 

 degree than higlier up the river, on the Hollandsch Diep and Ha- 

 ringvliet, is quite uukuowu on the Zuiderzee. For the fishermen of 

 this sea this animal is quite valueless. The specimens I saw all 

 belonged to Petromyzon fluviatilis. 



The sea-scorpion is also taken with the „kwak-" and „wonder- 

 kuil"-nets ; it is by uo means rare in the Zuiderzee in autuinn 

 and winter and most probably spawns there also. On Decem- 

 ber 14 some specimens were brought me which were in a far 

 ad vaneed stage of maturity — they were all of them females. In 

 the western part of the Baltic, which seems to have great analogy 

 with the Zuiderzee, the sea-scorpion spawns from November until 

 March. The fishermen say this fish is good for eatiug in Sep- 

 tember and October. 



The viviparous blenny is a rather common fish in the Zuiderzee. 

 When it is taken in May fishermeu are fond of eating it, as 

 they say its flavour is splendid in that month. It spawns in 

 autuniu , or more exactly at the begiuning of the winter, 

 and is viviparous. In December I took a couple of specimens 

 out of a kwakkuil ; they had the body-cavity filled with young 

 ones. These were small fishes of a length of about 40 millim., 

 about 200 in each mother; they showed already quite the ap- 

 pearance and even the characteristic pigmentation of the mother. 

 A free swimming specimen taken ll^h April 1888 ouly slightly 

 exceeded 40 mm. iu length; the explanation of this fact beiug 

 probably that the spawuiug period of this blenny exteuds into 

 the spring. 



Plaice and flounder are treated here together, as they are 

 almost always taken in the compauy of oue another: the appa- 

 ratus suitable for catching the oue flatfish takes the other also. 



luj the Zuiderzee the flounder is very common , the plaice 



