CHAPTER VII. 

 LIFE-HISTOKIES OF THE SPECIES. 



The Perch -Family. (Percidae.) 



The Sea-Peech. (Boccus lahrax, L.) 



The eggs of this species have not been procured in a ripe 

 condition, and indeed, on the east coast, the fish rarely comes 

 under notice. On the west coast, however, as at Southport, 

 observations should be comparatively easy. Day considered 

 that they deposited their spawn about the mouths of rivers 

 during the summer months ; while Couch states that July and 

 August are the breeding-months in Cornwall. Thompson 

 found the ovaries enlarged about the end of March, and the 

 eggs about the size of millet seeds. Raffaele found the ripe 

 pelagic eggs of the sea-perch in the Mediterranean from 

 January to the beginning of March, and from what has been 

 observed in a large female at St Andrews in May the spawning- 

 period would seem to be late, for the ova were comparatively 

 smalU. 



The eggs, which, according to Raffaele, range from 11 55 mm. 

 to 1"2 mm., have the usual pelagic characters, viz. a transparent 

 capsule, homogeneous yolk and an oil-globule with a diameter 

 of 0-3.33 mm. to 0-366 mm. (Plate I. fig. 2). Occasionally two 

 or three oil-globules may be present, as in the gurnard and other 

 forms. During the development of the egg blackish pigment 

 occurs along the dorsum, and yellowish pigment on the sides. 

 The latter colour also appears under the oil-globule. The 

 abimdance of the pigment and the large size of the chromato- 



1 W. C. M. 6«ft Ami. S.F.B. Report, 1888, p. 276. 



