802 



SCANDIXAVIAX FISHES. 



Ekstro.m has described the habits of the Ziirtlie in 

 the neighbourhood of MSrkO. At the approach of spring 

 it ascends the rivers, where it remains during the sum- 

 mer. Towards autumn it returns to the sea, where it 

 passes the winter, in so deej) water tliat it has never 

 been caught at this time of yeai-. It probably chooses 

 its winter-quarters outside the ishtnd-l)elt. In tlic hikes 

 too it retires to their deepest parts". 



Tunning and shy, like most of tlie ( '\prinoids, says 

 Kk'sthoii, it is difiicult to catcii, except during the 

 spawning-season, and dies soon after it has been taken 

 out of the water. It seldom attains any considerable 

 size. The fiesli is wliite, but flabby and of poor flavour. 

 In a female .">! cm. long and ' j„ kilo, in weight Block 

 estimated the number of the ova at 28,800, whence it 

 appears that the Zlirthe multiplies c^uickly enough; but 

 according to EkstrOm its growth is slow, and it thrives 

 OTdy in clear or running water witii a stony or sandy 

 bottom. 



In the stomach of tlie Zarthe Ekstrom seldom found 

 traces of other food than crustaceans, insects, worms. 



and, most often, the crushed sliells of mollusks {Neri- 

 fina); hardly ever of vegetable substances. 



At the end of May — still according to Ekstkom 

 — the spawning-season begins, and the Ziirthe ascends 

 such streams and rivers with stony bottom as fall into 

 the sea or the great lake where it has passed the winter. 

 The roe is deposited on and adheres to the stones, 

 against which the spawning fish eagerly rubs itself in 

 order to get rid of its burden. 



In spring and autumn, as it roves to and from 

 the spawning-place, small numbers of Ziirthe are taken 

 among other fishes with net and seine in Sodermanland. 

 During the spawning-season it is caught in a special 

 kind of large hand-net. 



In the localities affected by the Zarthe for the pur- 

 pose of spawning, continues EkstkOm, whei-e it may 

 consecjuently be taken in numbers, it always appears 

 on the labourer's humble board. It is generally but 

 little esteemed, and indeed requires skilful preparation 

 to suit a more delicate palate. Ekstro.m found it best 

 when fried. 



Genus ABRAMIS. 



Bt'f/iuiihiff of the dorsal lin sltuafed at a distaiice from the tip of the snout less than three times the length of 

 the head. Length of the base of the anal Jin more than ' ^ {21 — So %) of that of the Iwdi/, and greater as a 

 rule than that of the head. Pectoral fins shorter than the longest rag of the dorsal fin. Tip of the snout pro- 

 jecting onlg slightlg, if at (dl. in front of the mouth. Scales firmlg attached, Leuciscine in structure. 



This genus too is mainly European, and contains 

 only a few species (4 determined and recognised with 

 certainty, excluding hybrids). Still Meckel'' divided 

 it into 3 genera: AI)ramis, Blicca, and Ballerus, the 

 first with phar}-ngeal teeth set in a single row and the 

 base of the anal fin comparatively little elongated, the 

 second with two rows of pharyngeal teeth, the third 

 with pharyngeal teeth set in one row and the base of 

 the anal fin greatly elongated. The first two genera, 

 however, so closely resemble eacli other in all other 

 respects tiiat their division even into separate sub- 

 genera nmst appear unnatural. The character drawn 

 from the arrangement of tlie ])haryngeal teeth in one 

 or two rows has also been regarded by more recent 

 authors as insuflicient for the estaljlishment of distinct 



genera. The great elongation of the anal fin should 

 rather be employed for this purpose; but the species 

 are so few that the division is destitute of practical 

 impoi'tance. 



The three Scandinavian species may be distin- 

 guished as follows: 



A: Lengtli of the base of the anal fin less 

 than 3 ,„ of that of the body. 

 ((.- Length of the lower jaw less than ■' 4 



of the least depth of the tail Aliraiiiis blicca. 



t>: Length of the lower jaw more than 



•* 4 of the least depth of the tail Ahramis Ijrama. 



B: Length of the base of the anal fin more 



than ^ ,„ of that of the body _ .Ahvainis Imllerus. 



Besides these species, however, we must not forget 

 three hvbrids, which occur in Scandinavia as well as 



" In .\tter See (Austria) according to Heckel and Kner, it keeps at a deptli of 10 ftliins., in winter even '20; and the slioals in 

 wliich it is collected at this season betray their presence by rooting up tlie muddy liottom and iliscolonring the water. 

 '> Russeggers Reise, p. 10.S2. 



