880 



SCANDIX.WIAX FISHES. 



ill young speciineiis and tlu' feniales) it is of fairly 

 uniform height or highest in the anterior part (the 

 t)th — 8th ray), the height l)eing about 11^ — 14 % of tlie 

 length of the body. Sometiines again (at least in old 

 males) the posterior ])art of the fin (tlic Ifitli — 21st ray) 

 rises to a height of as much as ' ., of tlie length of 

 the l)(i(lv. The adipose fin is of the sume shape as in 

 tlie Salmons, forming a eurved lobe of fairly uniform 

 breadth. It lies nearly \ertically above the end of the 

 anal fin, the distance between it and the first upper 

 sujiporting ray of the caudal fin being about ' , — ' , 

 of the length of the body. The anal fin also resembles 

 that of the Salmons. It begins at a distance from the 

 ti]) of the snout (the articular knobs of the maxillaries) 

 which measures on an average about 71 % of the length 

 of the bodj'. The length of its base is 8 — 9 % (ex- 

 ceptionally 7 or 11 %), and its greatest height (the 

 length of the first or second branched ray) during youth 

 about 8 — 10 %, in old females about 10—11 %, and in 

 old males sometimes 1372 ^) of the length of the body. 

 Its hind infei-ior margin is convex. The caudal fin is 

 deeply forked, with pointed lobes. Its middle ra)s, 

 the relative length of which decreases with age from 

 a1)out 7 to 4 % of the length of the bod)', alwaj's 

 measure less than half, sometimes only one-third, of 

 the length of its longest rays. 



The pectoral fins are set low, witli almost hori- 

 zontal base. They ai'e obliquely pointed, and their 

 length is about 14 — 17 % of that of the body. The 

 ventral fins are as a rule somewhat shorter, but some- 

 times even longer, than the pectoral. They are also 

 broader and more obtuse. The distance between them 

 and the tip of the snout (the articular knobs of the 

 maxillaries) is about 46 — 48 % of the length of the 

 body. The preabdoininal length is on an average 28 %, 

 the postabdominal length 26 %, of the length of the bod)'. 



The scales are most like those of the Cyprinoids, 

 both in texture and shape. The}' are not onl}' larger 

 (fewei-), but also tlncker than tiiose of the Salmons, 

 and are furnished with radiating grooves. These are 

 especially deep in the anterior (inserted) part of the 

 scale, to which part they give an undulating appearance, 

 and the truncate margin of -which they render sinuate, 

 forming 3 — 5 indentations. The)' are very short at the 



])osterior, rounded margin of tlie scak', where they leave 

 only slight notches. The lateral line follows a fairly 

 median course, in front somewhat nearer to the back 

 than to the belly. The middle part of its scales pro- 

 ject at the inserted margin in a rounded form. The 

 ordinarv scales cover the whole body, but leave most 

 of the fins, the head, and a greater or less portion of 

 the breast naked". The base of the caudal fin is, how- 

 ever, clothed with smaller and thinner scales, and this 

 covering follows the caudal rays, especial!}' the longest 

 ones, the scales here growing gradually smaller outwards 

 and being of a linguiform shape, calling to mind in their 

 structure the scales we have seen above in JllnUofus. 



Its varied and shifting colours render the Gray- 

 ling a. handsome fish. Dark and light phases of colour 

 follow with different environments, and the Grayling, 

 like so many other fishes, has a particular festal dress. 

 The ground-colour of the back is brown or grayish, 

 shading into blue, green, or a purplish lusti-e in dif- 

 fei-eut lights. The sides are lighter, those of tlie head 

 witli a metallic lustre, those of the body with a .silvery 

 lustre or a tinge of yellow. The belly is of a more 

 or less pronounced silvery white. Along the sides of 

 the body, between the back and belly, run a number (up 

 to 16) of dark, parallel stripes, marking the limits l)c- 

 tween the regularly arranged r(_)ws of scales; and be- 

 sides there lie sharply defined, dark spots, reminding 

 us of the coloration of the Salmons, irregularly scat- 

 tered on the sides of the head and varying in occur- 

 rence, but sometimes distributed in longitudinal rows, 

 es])ecially on the forepart of the sides. The fins of the 

 ventral side are }ellowish or ashy gray at the base 

 (sometimes throughout), towards the top (especially the 

 posterior ones) violet. The caudal fin, as ^vell as the 

 adipose fin, is Iduish gra}', violet, or even of the same 

 dai-k hue as the back. Most prominent is the coloration 

 of the large dorsal fin, which is of an iridescent violet 

 or lake, with three or four rows of dark, quadrangular 

 spots, generally ocellated in lake, on the fin-membrane 

 between the light rays. In the spawning-dress all these 

 colours are heightened, ajid the body gleams with a 

 golden lustre. 



The peritoneum is white. The short esophagus 

 passes into a very thick-walled stomach'', which extends 



" At the median line the lielly is usually covered with scales (even if these are only small) forward to a line with tlie insertion of 

 the pectoral fins; but on each side and in front throughout the whole ventral side the skin is naked. The variations in the extent of thiii 

 scaleless part led Valenciennes to establish the species gymnothora.v and gymnogastcr. 



^ In a male 55 cm. long the wall of the stomach is 6 mm. thick. 



