312 



A HISTORY OF FISHES 



being attacked by rooks and carrion crows, which thrust their 

 sharp beaks through the abdominal wall and feast on the liver 

 of the unfortunate fishes. If removed from the eggs and then 

 released, they will at once rush back to their posts, and after 

 a heavy storm that has swept masses of eggs from their normal 

 positions high up on to the beach, as soon as the sea becomes 

 calm again the parents may be seen anxiously seeking for their 

 charges. 



The Gunnel or Butter-fish (Pholis), an elongate Blenny-hke 

 fish, some ten inches in length, is in the habit of rolUng its mass 



Fig. 112. 

 Gunnel or Butter-fish (Pholis giinnelhis) with mass of spawn, X \. 



of spawn into a ball, about the size of a Brazil nut, an operation 

 in which both parents may assist. Afterwards, one of them 

 remains on guard, coiled round the eggs, but it is not certain 

 whether this is the male or the female, or whether both take 

 their turn. Often the mass of eggs, accompanied by the parent 

 fish may be found between the valves of empty oyster shells, 

 or in the holes made by boring molluscs in the rocks (Fig. 112). 

 In the Indo-Pacific genus Kurtus, the male is provided with 

 a bony hook projecting from the forehead, supported by a 

 special process of the skull. The mass of eggs is produced in 

 two bunches connected by a string, and this becomes attached 



