818 



SCAXniN AVIAN FI.SIIES. 



Abrainis Heckelii, Sei.. Longcii., Fne Beige, p. 217. 



Hybrid between Abraniis briuna and Leuciscus rutilus, Gthr, 



Cat. Brit. Miis., Fish., vol. VII, p. 214: LiLU. (p. p.), Sv., 



.Xoiy. Fit., Fish., vol. Ill, p. 287. 



Oi this t'oriii, wliicli according to Siebold attains 

 a length of al)out 31 cm. (to the extreme tips of the 

 caudal lobes), we have heen in a position to examine 



three specimens 17 — 22 cm. lung (t(j tlie end of tlie 

 middle caudal rays), all three taken in Dalecarlia by 

 Dr. Stkffexburg, and two others, resp- 20 and 32 

 cm. long, from the Helge River (Scania). Instead of a 

 description at length we shall here give those average 

 measurements of the first-mentioned three specimens 

 which express the most important relations of form. 



Length of the hody expressed in mi Hi metres 



Length of the heiiil in % of the length of the body 



Gre.itest depth of the hody „„:, „ „ !> ,i .. 



Greatest thickness of the body „ „ „ „ „ ?, m ^, 



Least depth of the tnil „„„ „ „ „ „ „ 



Distance between the dors.il tin ami the tip of the snout „ „ „ „ „ „ „ „ 



Length of the base of the dorsal tin , „ „ „ „ „ „ „ 



,, „ „ longest ray of the dorsal tin ,, „ „ „ „ „ „ „ 



Distance between the anal tin and the tip of the snout „ „ „ „ „ „ „ „ 



Length of the base of the anal tin „ „ „ „ „ „ „ „ 



„ ,, „ longest ray of the anal tin ,, „ „ „ „ „ „ „ 



„ „ „ middle rays of the caudal tin „ „ „ „ „ „ „ „ 



„ ., „ longest ray ,, „ ,, „ „ „ „ „ „ „ „ „ 



„ „ „ pectoral fins „ „ „ „ „ „ „ „ 



„ „ „ ventral „ , „ ,, „ ., ., ., „ „ 



Distance between the ventral tins and the tip of the snout ,, „ „ „ „ ., „ ,", 



Preabdoininal length „ „ „ „ „ -, ., „ 



Postabdoininal ,, „ „ „ ,, „ ,, „ „ 



Length of the peduncle of the tail behind the perpendicular from the termination of the base of the anal tin „ „ „ „ „ „ „ „ 



Diameter of the eyes „ „ „ „ „ „ „ liead 



Length of the snout — - „ „ „ „ ,, „ „ „ 



Breadth of the interorbital space „ „ ,, ,, ,, „ „ „ 



Length of the upper jaw from the tip of the snout „ „ „ ,, „ „ „ „ 



., „ ., suboperculuTn at the upper margin - „ „ „ „ „ „ „ „ 



193 



21.9 

 31.8 



(9.3) 

 lO.i 

 49.7 



13.5 



(23.0) 

 r,2.8 



17.2 



(15.5) 



9.4 



(20.4) 



(18.1) 



(16.5) 



42.8 

 20.9 



(20.5) 

 l.i.9 

 23.9 



(30.3) 

 37.5 

 29.5 

 35.2 

 35.6 



The characters of the Roach here find expression 

 in the comparatively short lower jaw and pectoral fins, 

 in the forward position of the dorsal fin and its com- 

 jjaratively long base, and in the comparatively great 

 postabdominal length. The influence of the Bream type 

 may be traced, on the other hand, not onlv in the 

 great depth of the body and, relatively, of the pe- 

 duncle of the tnil, but also in the height of the dor.sa.l 

 and anal fins and in the comparatively great preab- 

 ilominal length. 



Blocii described this form from Swedish Pomerania, 

 Meckel and Siebold from Central Germany and Austria, 

 NouDMANN from the Lower Danube, Valenc;iennes from 

 France, Selys-Longchamp.s from Belgiiun, Yaerell and 

 GuNTHEU from England. According to THo.Mr.soN it 

 also occurs in Ireland; but this statement seems to re- 

 quire further corroboration, for, as Day" has remarked, 



the Roach does not belong to the Irish fauna. In Swe- 

 den this hj'ltrid had as yet l)een found, to the best of 

 our knowledge, only in Dalecarlia and, according to 

 LiLLJEBORG, in the Klar Elf, until we received very re- 

 cently (May, 1893), through Fisherman Billing of Kris- 

 tianstad, two splendid specimens from the broad below 

 that town on the lower course of the River Helge. 



The German name of Leiter (Leader) has been con- 

 ferred on this hybrid as well as on several other more 

 or less singular fishes that occur in .solitary specimens 

 among a shoal of some common species, and are there- 

 fore supposed to pilot their comrades. A catch of this 

 kind is enough to give the fisherman hope of a plenti- 

 ful take of Bream. 



Like the Cvprinoid hyltrids in general this form 

 too is prolific, the spawning-season occurring in Ger- 

 many, according to Siebold, at the end of April. 



" Fish. Gt. Brit., Irel., vol. II, p. 196. 



