BULLETIN OF THE UNITED STATES FISH COMMISSION. 41 



" The Pilot-fish {N. ductor) is a truly pelagic flsli, known in all tropical 

 and temperate seas. Its name is derived from its habit of keeping com- 

 pany with ships and large fish, especially Sharks. It is the Pompilusof 

 the ancients, who describe it as pointing out the way to dubious or em- 

 barrassed sailors, and as announcing the vicinity of land by its sudden 

 disappearance. It was therefore regarded as a sacred fish. The con- 

 nection between the Shark and the Pilot-fish has received various inter- 

 j)retations, some observers having perhaps added more sentiment than 

 is warranted by the actual facts. It was stated that the Shark never 

 seized the Pilot-fish, that the latter was of great use to its big companion 

 in conducting it and showing it the way to its food. Dr. Meyen, in his 

 'Eeise um die Erde,' states : ' The Pilot swims constantly in front of the 

 led by the Pilot. When the Shark neared the ship the Pilot swam close 

 Shark; we ourselves have seen three instances in which the Shark was 

 to the snout or near one of the pectoral fins of the animal. Sometimes 

 he darted rapidly forwards or sidewards as if looking for something, and 

 constantly went back again to the Shark. When we threw overboard a 

 piece of bacon fastened on a great hook the Shark was about twenty 

 paces from the ship. With the quickness of lightning the Pilot came 

 up, smelt at the dainty, and instantly swam back again to the Shark, 

 swimming many times around his snout and splashing, as if to give him 

 exact information as to the bacon. The Shark now began to put himself 

 in motion, the Pilot showing him the way, and in a moment he was fast 

 ujion the hook.* Upon a later occasion we observed two Pilots in sed- 

 ulous attendance on a Blue Shark which we caught in the Chinese Sea. 

 It seems probable that the Pilot feeds on the Shark's excrements, keeps 

 his company for that purpose, and directs his operations solely from this 

 selfish ^^ew.' We believe that Dr. Meyen's opinion, as expressed in his 

 last words, is perfectly correct. The Pilot obtains a great part of his food 

 directly from the Shark in feeding on the parasitic crustaceans with 

 which Sharks and other large fish are infested, and on the smaller pieces 

 of flesh which are left unnoticed by the Shark when it tears its prey. 

 The Pilot also, being a small fish, obtains greater security when in com- 

 pany of a Shark, which would keep at a distance all other fishesof prey 

 that would be likely to prove dangerous to the Pilot. Therefore in ac- 

 companying the Shark the Pilot is led by the same instinct which makes 

 it follow a ship. 



" With regard to the statement that the Pilot itself is never attacked 

 by the Shark, all observers agree as to its truth ; but this may be ac- 

 counted for in the same way as the imi)unity of the swallow from the 

 hawk, the Pilot-fish being too nimble for the unwieldy Shark. 



" The Pilot-fish does not always leave the vessels on their approach 

 to land. In summer, when the temperature of the sea-water is several 

 degTees above the average. Pilots will follow ships to the south coast of 



*Iu this iustance one may eiltertain reasonable doubts as to the usefulness of the 

 Pilot to the Shark. 



