168 Part III—Twenty-fourth Annual Report 
The external differences, however, between the two fish appear so 
slight to a beginner that it takes him some considerable time to separate 
even small quantities of one from the other; and it is only after he has 
handled several thousands of fish, or has otherwise had long experience 
of them, that he is able to separate the one from the other with any 
degree of comfort and rapidity. 
The proper method is, therefore, to first of all accustom the eye to the 
differences in the general shape and colour of the two fish; but to make 
sure, the thumb or forefinger must be drawn along the throats of the 
fish, when the sharp spines in the case of the sprat at once distinguish it 
from the comparatively smooth-throated young herring. 
If in doubt about the general shape, colour, and spines, the position of 
the pelvic fins in relation to the first ray of the dorsal fin must be noted, 
and if still in doubt the number of rays in the pelvic fins themselves 
have to be counted. 
In very small and semi-trausparent fish the number of vertebra have 
to be counted. 
The following Table shows the general external differences between the 
two fish :— 
Sprat. Young Herring. 
General shape. . | Deeper and narrower in the | Relatively not so deep in the 
body. Belly curved from body, and much less curved 
head to tail. in the belly ; whole body 
usually more tapering to- 
wards tail. 
Colour. . : . | Narrow strip of slaty blue col- | Broader strip of greenish blue 
our on back, Sides of body colour on back. 
relatively more silvery. 
-____---:-- OO | Oo Oe Se — | eee 
Head. . : . | Short from snout to occipital | Relatively longer. 
region. 
Spines. . . - | Well developed on throat and | Weak on throat and not so well 
belly. developed on belly. 
Eyes. . 5 - | Small. Relatively large. 
el 
Position of Pelvic | In nearly all fish above, but | In nearly all fish above, but 
Fins, sometimes below, 5 cms. in sometimes below, 5 cms. 
front of first dorsal fin ray. behind first dorsal fin ray. 
Number of Rays in | 7, usually. 9, usually. 
Pelvic Fins. 
Dailsa xe . | Greyish in colour and usually | Darker fringe and more uni- 
ragged. form in shape. 
Vertebre, . : Not more than 48. Not less than 54, 
