1002 
SCANDINAVIAN FISHES. 
The cephalic system of the lateral line has very 
distinct and deep pores in the thick skin. In each 
fronto- rostral branch there usually appear 4 pores along 
the forehead and snout; in the suborbital branch (tig. 
253, sob — pob) 9 or 10 in a row surrounding the lower 
part of the eye and advancing along the snout to a 
point just in front of the nostrils; in the mandibular 
branch 5 pores on the under surface of the lower jaw 
(de) and -6 at the preopercular margin. The occiput 
is crossed on each side by a serpentine groove (the 
supraorbital branch, cf. above, fig. 104, p. 368), ending 
at the outer extremity in a similar pore, from which 
a row containing 3 or 4 pores runs back, along the 
temple, to the upper angle of the gill-opening. The 
body is covered with soft, middle-sized, and imbricated 
scales (fig. 254), each enclosed in a thin follicle and 
naked only at the tip, which appears in a small, an- 
of the length of the abdomen, measured from the an- 
terior (lower) end of the shoulder-girdle. 
Among the seven fins the vertical, which are si- 
tuated on the tail, are most developed, forming the 
propeller by the aid of which the Pike darts like an 
arrow on its prey. The dorsal fin is high and rounded. 
It begins vertically above the vent, at a distance from 
the tip of the snout measuring 67 — 69 % of the length 
of the body, and terminates above the end of the anal 
fin. Its base measures about 1 1 l j 2 — 137 2 % b , and its 
longest ray about 40 7 2 — 1 1 7 2 0/o ° •> °f P‘ e length of the 
body. The anal fin is similar to the dorsal, but shorter, 
usually almost as high as it is long. Its distance from 
the tip of the snout is about 71 — 74 % d , its base about 
107 * — 97 2 % i and its height about 10 — 11 %, of the 
length of the body. The caudal fin is slightly forked. 
The middle rays, which occupy about 6 — 7 % of the 
A. 
B. 
c. 
Fig. 254. Scales of the Pike. 
X 2: A, from the anterior part of the body, above the lateral line; B, from the lateral line; 
C, from the ventral side. 
gular opening, usually of a distinctive colour. In shape 
they are rounded and oblong, or (on the belly) more or 
less pointed behind; and they are most distinguished 
by the cleavage of the anterior (inserted) part into three 
or four lobes. The lateral line is straight, and runs 
somewhat nearer to the back than to the belly. It is 
marked by scales incised at the tip, but is interrupted 
here and there by scales with entire tip. On each side 
of the lateral line, especially on the tail, there are 
scale-rows similar in the structure of the scales to the 
lateral line, but varying in number, extent, and position. 
At the outer angles of the ventral fins the usual scale- 
flap" is wanting. 
The anal aperture, which is large, lies so near to 
the caudal fin that its distance therefrom is only 7 3 
length of the body, are about half as long as the long- 
est rays in the fin. 
The pectoral fins are obliquely rounded and set low. 
Their length in adult Pike is about 10 — 13 % of that 
of the body. The ventral fins are of about the same 
size. They are situated half-way along the body, and 
the preabdominal length is about 7 4 (in gravid females 
as much as 7io)> 4i ie postabdominal about 1 / 5 (in gravid 
females somewhat more), of the length of the body. 
Without any examination of the internal organs, the sex 
may be determined by the fins, which are generally larger 
and more rounded, with thicker rays, in the male than 
in the female. The length of the pectoral fins, in parti- 
cular, is somewhat more in the male, less in the fe- 
male, than half of the preabdominal length. 
“ Cf. above, on the Loaches (p. 709 and note d) and on the Minnow (p. 756). 
b In the fry about 36 — 38 %, in Pike 4 — 5 dm. long about 44 — 47 %, of the length of the head. 
c In the fry about 34 — 38 %, in Pike 4 — 5 dm. long about 38 — 43 %, of the length of the head. 
' 7 In the fry about 2 / 3 ; in the males commonly less than in the females. 
