586 LÖNNBERG, OBSERVATIONS ON CERTAIN FLAT-FISHES. 



A variety of the plaice mentioned so long ago as by Gott- 

 SCHE and låter author* since, is the one called by the fishermen 

 '■hansins" or "hansaspätta". The specimens of this are all 

 verv large with big heads upon which the frontal ridge and the 

 five tubercles are obsolete. The anal spine is also verv often 

 nearly obsolete All the specimens, I have seen, were females. 



The plaice is a verv sluggish fish and when caught in the 

 nets it does not make exertions to free itself. As soon as it 

 feels in the least caught it remains in the nets and very often 

 the meshes are only loosely fastened behind the protruding eyes. 

 The plaice remains passive howev'er although only a very slight 

 movement would set it free, and when il is being dragged out 

 of the water, it only falls back thanks to its weight, supposing 

 it is not well fastened. When it is caught and thrown on the 

 dry deck it sometimes wriggles violently for a little while, and 

 is then very strong, but often it lies perfectly quiet even there. 

 In contrast to the sluggish plaice, the small dab is a very lively 

 little fish and even the smallest of that kind. if caught in a 

 net, tangles the same and winds it together in the most fearful 

 manner. But in most cases it kills itself in that way. The 

 easiest to keep alive of the more important flatfishes in Cattegat 

 are the plaice and the turbot. The brill is not so easy and 

 Pleuronectes microcephalus can hardly be carried alive from the 

 fishinggrounds near Anholt to the marketplaces on the shores 

 of the Sound. The sole is very tenacious of life, but when 

 kept in the cauf of the tishing-vessel it is apt to crawl into 

 corners and cracks where it gets stuck and thus gets killed. 



By measuring a great number of difterent flatfishes and 

 dissecting them I tried to find out the size at which they are 

 ready for spawning.^) I found, then, that the males are mature 

 at a smaller size than the females. — The male brill is perfectly 

 mature at a total length of 32 — 30 cm. The turbot is still 



^) Arch. f. Naturgesfh., Bd. I, Berlin 1835. 



■^) I have written on this subject before in: Svenslv Fiskeritldskr., Arg. o, hatt. 

 .1, Sthlm 1894. 



