CRUCIAN CARl'. 



739 



reSL'iublc those of tlie Lake Crucian ("arp; iiiid this ap- 

 plies also to the nostrils, thougli tlicy arc sometiiiies 

 set a little liiglier. 



The scales are like tliose of the preceding variety 

 in form, number, and distribution. Tin; lateral line 

 shows some difference, being generally somewhat more 

 curved, and lying nearer the back. The position of the 

 vent is the same. 



The dorsal fin, which in the number of the rays 

 resembles that of the Lake Crucian ("arj), is distin- 

 guished from tlie latter by the <litiiculty wliich often in- 

 volves the detection of the iirst ray, and which not un- 

 freipiently causes this ray to be overlooked. In form the 

 flirt'erence is greater, the dorsal tin of the Pond Crucian 

 (.'arp being always liigher in front and less arcuate at 

 the margin. The anal tin may l)e recognised by its 

 somewhat greater height and less rounded anterior cor- 

 ner. The caudal tin, even when strongly expanded, and 

 even in old and large Pond Crucian Carp, is concave at 

 the hind margin. The pectoral and venti-al tins of the 

 two varieties are alike in all essential respects. The above 



differences in llic form of tlie lins in general range the 

 Pond Crurian Cai'p uii a ie\cl witii young individuals. 



The cciidralioii of tills variety is generally darker 

 than that of tiie Lake Crucian ('arp. The back is of a 

 dark olive green, and the top of the head still darker. 

 The dark tint of tiie back grows somewhat lighter down 

 tiie sides, the iiuiei- coat of brassy yellow being more 

 distinct here than (ju the Ijack, where it is often in- 

 xisiltle. The l)elly is dark yellow. The dorsal iin is 

 of the same colour as the back; the other fins are gray, 

 more or less deeply tinged witii i-ed. The iris is brassy 

 yellow, but often I'endered brown In' the dense dots 

 with which it is strewn. The pupil, however, always 

 lias a tine, brassy yellow rim. 



In the sti'ucture and arrangement of the internal 

 organs there is only one difference: in the air-])ladder 

 of the Pond Crucian Carji the round anterior part is 

 compai'atively larger, and the posterior part not so 

 sharply curved, shorter, and nai'rower, a circumstance 

 which seems to depend on the stronger contraction of 

 the iiind part of the al)doniinal cavity. 



The Crucian Car}), which in Scania and Bf)huslan is 

 called Karussa (probably from the Danish Karudse), oc- 

 curs almost everywhere in Sweden, even in the District 

 of Norrl)otti'n". hi Norway and Finland, according to 

 CoLi.ETT and Mkla, tiie northern range of the Crucian 

 Carp is al)out equally great, extending to at least 66° 

 N. lat.'' The individuals that occur in these northern 

 regions do not, however, attain any considerable size. 

 The ajiecies seems also to diminish in size towards the 

 west, for though even in the District of Gefleborg it 

 attains a weight of 3',., lbs. (17 hectogrammes), Collett 

 mentions a sjjecimen 260 ram. long as the largest Cru- 

 cian Carp from the neighbourhood of Christiania ])re- 

 served in the University ^luseum of that city; and this 

 specimen proliably weighed no more than 7 or 8 hecto- 

 grannnes. In the central and southern })rovinces of 

 Scandinavia the species is extremely common, and it is 

 here too tiiat it attains the greatest size. In Wermland 

 it is rarer and smaller. The Crucian Carp is also spread 

 over the whole of Europe" and Central Asia, together 

 with Siberia, eastwards to Amur and China. 



Tlie favourite haiuits (»f tiie Crucian Carp are small 

 lakes with shallow water and weedy and oozy bottom. 

 When it is found in larger pieces of water, as in the 

 western island-belt of the Baltic or Lakes Wener, Wetter, 

 and Hjelmar, its occurrence is confined to shallow, weed}', 

 and mudd-\- inlets. It also thrives well in small ponds, 

 peat-haggs, and other collections of stagnant water, and 

 is the only one of our indigenous fishes, except the 

 Three-spined Stickleback, that is plentiful and multiplies 

 freely in such localities, for the Carp cannot be regarded 

 as an indigenous Scandinavian species. Hence the Cru- 

 cian Carp, like the Carp, is kept in ponds, almost as a 

 domestic animal, to supply the wants of the table. It 

 can even put up with polluted w ater. Pallas also tells 

 us that the Crucian Carp, which does not even disdain 

 the salt water of the steppes, is the first fish to make 

 its appearance in new-formed lakes and fens, of which 

 fact he saw instances in the basin of the Isset, a tri- 

 butary of the Toljol (Siberia). 



In such small pools, where there is never a suf- 

 ficiency of food for any considerable number of fishes, 



" Cf. Undcrd. Bet. Fiirsl. Xy Fiskeristadga 188.3, Bilaga III, p. 168. 



'' Gbimm (Fishing nml Huntituj on Russian Waters 188.-i, p. 13) sets tlic northern limit of the Cnieiai. Carp's range in Russia at 

 "about 65° N. lat." 



' .\rosTOLlDEs (La Peche en Orece, 1883), liowever, does not include tlie Crucian Carp among tlie iislies of Greece. 



