THE FLAT-FISHES 221 



180 score of plaice apiece each day, the plaice having no 

 doubt followed the food. 



The Dab (P. limanda), a light-brown fish that lacks the 

 red spots of the plaice, but has similar spots in dull brown, 

 is, on account of its spiny scales, a rougher fish when 

 handled. The ridge over the eyes is, however, smooth, not 

 rough as in the plaice. The lateral line also has a charac- 

 teristic abrupt curve round the pectoral fin. As in the 

 plaice, there is a spine before the anal fin, but, unlike the 

 plaice, the present species has scales along the rays of the dorsal 

 and anal fins. The largest recorded dab in British waters 

 measured 15 in., and examples of 10 in. are much more 

 common. The females are both slightly larger and also 

 much more numerous than the other sex. 



The dab, the smallest member of the genus in our seas, 

 is a northern fish, being absent from the Mediterranean, 

 but occurring throughout the Baltic. It feeds chiefly on 

 hermit-crabs and other crustaceans, as well as on sand-stars, 

 razor-fish, and worms. It attains to maturity when 4 or 5 in. 

 long, and spawns at a considerable distance from the land 

 between March and June. Dr. Wemyss Fulton has reckoned 

 that a dab of 8-| in. deposits 128,812 eggs. The egg is 

 smaller than that of the plaice, and, like it, has no oil-globule. 

 It measures only about yIt iii- Cunningham succeeded in 

 artificially fertilising them at sea in 1886, and he also hatched 

 them at the Granton Laboratory. At a temperature of 

 between 45° and 60° F. they hatched in three days, but at 

 St. Andrews in May, at a much lower temperature, they took 

 twelve. The larva measures rather over yo ^^-i ^^^ has light 

 yellow spots on the head and tail. 



Young dabs, plaice, and flounders can only be distin- 

 guished with the greatest difficulty. The number of fin-rays, 

 of which much is sometimes made, is not a very reliable 

 character as distinguishing dabs from plaice, though it effectually 

 separates both from the flounder. Prof. Mcintosh alludes to 



