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 

 fisb, 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-transparent fish the number of vertebrae 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 

 body. Belly curved from 

 head to tail. 



Relatively not so deep in the 

 body, and nauch less curved 

 in the belly ; whole body 

 usually more tapering to- 

 wards tail. 



Colour. . 



Narrow strip of slaty blue col- 

 our on back. Sides of body 

 relatively more silvery. 



Broader strip of greenish blue 

 colour on back. 



Head. . 



Short from snout to occipital 

 region. 



Relatively longer. 



Spines. . 



Well developed on throat and 

 belly. 



Weak on throat and not so well 

 developed on belly. 



Eyes. 



Small. 



Relatively large. 



Position of Pelvic 

 Fins. 



In nearly all fish above, but 

 sometimes below, 5 cms. in 

 front of first dorsal fin ray. 



In nearly all fish above, but 

 sometimes below, 5 cms. 

 behind first dorsal fin ray. 



Number of Rays in 

 Pelvic Fins. 



7, usually. 



9, usually. 



Tail. 



Greyish in colour and usually 

 ragged. 



Darker fringe and more uni- 

 form in shape. 



Vertebree, 



Not more than 48. 



Not less than 54. 



