Scientific Intelligence, — Zoology. 196 



amples of this family of Cephalopodes, from the equator to Lats. 



34^ N. and 16^ S., Pacific Ocean Bennetts Whaling Voyage, 



vol. ii. p. 290. 



17. The Pilot Fish {Gasterosteus ductor, Linn.) — The average 

 length of this fish is about six inches, though we took one example 

 in the Pacific which measured one foot two inches. The body is 

 somewhat cylindrical, and neatly formed. The colour of the head 

 and back is steel-blue ; abdomen silvery ; sides marked with five 

 broad black bands ; fins mottled black and white, and mostly tipped 

 witli white ; inner circle of the iris hazel, outer gold-yellow. A 

 single row of teeth in each jaw. Three short spines in front of the 

 dorsal fin, and two in front of the anal. The lateral line is oblique, 

 and terminates posteriorly in a semi-cartilaginous ridge, projecting 

 from either side of the tail. The female is oviparous. 



Pilot-fish are almost invariably found in attendance upon the 

 shark, though the nature of their connexiou with that ferocious fish 

 is somewhat mysterious. They will accompany ships for a consi- 

 derable time after their patron shark has been destroyed ; but I am 

 not aware that they have ever been, like the Remora, attending 

 upon other large fish, whales, or miscellaneous floating bodies. 

 The structure of their mouth, and the contents of their stomat:h, 

 which are usually small fish, denote that they are accustomed 

 to seek their food in a very indepeudent manner. We cap- 

 tured many of them also by hook and line, baited with flesh ; nor 

 did they refuse the bait even when they were in company with a 

 shark. 



The reputation this fish has obtained of being the shark's pilot 

 or provider (and which has sanctioned its trivial name), would ap- 

 pear to be groundless, were we guided only by the want of similar 

 precedents in the animal kingdom. A fact, however, which came 

 under my notice during a voyage from India, in the year 1832, led 

 me to believe that there is some just foundation fur this popular 

 opinion. While we were becalmed in the Atlantic Ocean, a shark 

 was seen close to the ship, and attended by two pilot-fish, which 

 generally swam one above the other below him, and occasionally 

 went off to some distance, as if to explore the surrounding sea ; al- 

 though it was seldom long before they returned, and resumed their 

 former positions ; the shark in the mean time, by its unwieldy 

 form, slow movements, and lethargic aspect, offering a strong con- 

 trast to the spri<^htliness of his scouts. A baited hook was lowered 

 from the bow of the ship ; but the shark, when alone, passed it se- 

 veral times without notice, and apparently without seeing it. One 

 of the foraging pilot-fish then approached the bait, and imiuecliately 



