PERCH-LIKE FISHES 135 



some may descend to considerable depths. Fossil remains 

 have been found in Oligocene and Miocene deposits. 



ESCOLARS OR OIL-FISHES. 



(Genus Ruvcttus.) Fig. 44. 



The belly is keeled, and the whole of the head and body is 

 covered with minute smooth scales and also with sharp, forked 

 prickles. The spinous dorsal fin, with 13 to -15 spines, is close 

 to or touches the soft dorsal. There are two detached finlets 

 (much branched single rays) behind both the dorsal and the 

 anal fins. The general coloration is grey, black or purple- 

 brown, becoming paler on the lower parts ; the inside of the 

 mouth is dusky. 



Grow to a length of 6 feet and a weight of 100 lb. 



The Common Escolar or Oil-fish (R. pretiosus) is found 

 in deep water in the warmer parts of the Atlantic and 

 the Mediterranean, and there is one record from quite near 

 the British Isles. A closely related species, the " Palu " 

 or Pork-fish (R. tydemani), occurs in the Indian and Pacific 

 Oceans. 



Practically nothing is known of the habits of this interesting 

 fish, which is abundant in certain localities, and is normally 

 found at depths of from 200 to 400 fathoms. It is of impor- 

 tance commercially, and is caught on long lines off Madeira, 

 about Cuba and elsewhere. The late Professor Jordan remarks 

 that the Cuban fishermen go "a scholaring " (" a escolarear "), 

 after fishing for, the Spear-fish has finished and before that 

 for the Red Snapper begins. In the South Seas the natives 

 set out to catch these fishes on nights when there is no wind 

 and no moon, using a peculiar and very characteristic fish- 

 hook. Dr. Gudger tells us that the " Palu-hook ", as it is 

 called, " is made from the fork of a bush or tree, the trunk 

 furnishing the shank leg, the branch the barb leg. . . . The 

 barb is separately made from a nearly right-angled fork. It 

 and the top of the barb leg are spliced to fit and the barb is 

 lashed on to the top of the barb leg. It is fitted to point 

 obliquely inward and downward, but slightly to one side of 

 the shank ". The bait is a flying-fish or other delicacy, and 



