ICHTHYOLOGY. 



185 



Acanthop. 



tervpii. 



Scunibe- 



rida;. 



the genera of the first great tribe, in wliich the posterior 

 portion of the second dorsal and of tlie anal fin possess 

 no continuous membrane between its rays, which thus re- 

 main free and disconnected, under the name of finlets. 

 But in the group which we are about to enter it is the 

 anterior dorsal which wants the membrane, and of which 

 the rays are consequently free, and capable of isolated 

 movement. Certain species even conjoin with this cha- 

 racter that of the preceding tribe, and have finlets behind, 

 at the same time that they possess free rays upon their 

 anterior portion. 



Genus Naucrates, Rafin. Dorsal spines free ; body 

 fusiform ; a carina or keel on the sides of the tail, as in 

 the tunny, and two free spines before the anal fin. 



This genus contains N. ditctor, the fdmous pilot Jish of 

 navigators (Gasterosteus dwtor, Linn.), so named from its 

 habit of keeping company with ships at sea, and frequent- 

 ly swimming beneath their bows. It would seem, from 

 early indications of a similar instinct, to be the Pompilhis of 

 the ancients, described as pointing out the way to dubious 

 or embarrassed sailors, and as announcing the vicinity of 

 land by its sudden disappearance. It was thus regarded 

 as a sacred fish. The other story of its serving as a guide 

 to the shark does not appear to have been transmitted to 

 us from so remote a source. It is not mentioned even by 

 the Ichthyologists of the sixteenth century ; and Cuvier 

 regards as the first allusion to it, that of Dutertre in his 

 Description of the Antilles, printed in 1667. Since that 

 period it has been carefully repeated by all voyagers 

 and compilers ; and Osbeck even makes it a subject of 

 pious reflection on the wonderful ways of Providence. We 

 are told by a greater than Osbeck that " they that go 

 down to the sea in ships, that do business in great waters ; 

 these see the works of the Lord, and his wonders in the 

 deep :" but the fact in the present instance seems reduci- 

 ble to this, that the pilot accompanies both ships and 

 sharks, sometimes swimming before, sometimes behind, 

 for the sake of preying upon whatever may be thrown 

 over board in the or e case, or left uneaten in the other. 

 It is true that the shark never attacks it ; but it is also 

 true that the hawk does not attack the swallow ; and in 

 both instances the reason is the same ; the pilot being too 

 nimble for the unwieldy shark in the water, just as the 

 feebler but more agile bird is too swift in its movements 

 fur falco in the air. It is thus that the apparent alliance 

 of these dissimilar fishes may be explained even upon ge- 

 neral principles, to say nothing of Bosc's observation, who 

 assures us that he has seen hundreds of pilot-fish, that 



they always keep at a respectful distance from the shark, Acantliop. 

 and swim about swiftly in different directions, that they terygii. 

 may more certainly avoid it. If any food be thrown over 

 board, the pilot stops to seize it, and abandons both the 

 shark and vessel. Geoffroy no doubt tells a story of two 

 ])ilot-fish having been seen to take a great deal of trouble, 

 swimming to and <Vo, in order to conduct a shark towards 

 a baited hook ; but admitting the truth of the details, it is 

 clear, that whatever advantage might eventually accrue to 

 the conductors, the probable result to the shark was a 

 cruel death, and one is consequently the more inclined to 

 admire how the narrative itself should find place in a 

 Memoir Sur rajfertioii nmtiielle des quelques animaux I' 



The pilot-fish in question is chiefly a Mediterranean 

 species, although it also spreads into distant oceans, hav- 

 ing been found by Daldorf under the equator. A great 

 extent of geographical distribution may indeed be expect- 

 ed in reference to a species which is said to suffer itself 

 to be led away immense distances in its eager pursuit of 

 ships. Dutertre records that he saw one which followed 

 his vessel for more than 500 leagues. Whether he kept his 

 eye upon it night and day during all that time, or in what 

 other way he ascertained it to be the same individual 

 throughout so long a traverse, is what he does not state, and 

 we therefore cannot explain. " In the year 1831," Mr Yar- 

 rell observes, " two specimens of pilot-fish were caught on 

 the opposite side of the British Channel, and more than one 

 instance has occurred of their following ships into Guern- 

 sey. A few years since, a pair accompanied a ship from the 

 Mediterranean into Falmouth, and were both taken with 

 a net. In January 1831, the Peru, Graham master, put 

 into Plymouth, on her voyage from Alexandria for Lon- 

 don, after a passage of eighty-two days. About two days 

 after she left Alexandria, two pilot-fish, Gasterosteus duc- 

 tor, made their appearance close alongside the vessel, 

 were constantly seen near her during the homeward voy- 

 age, and followed her into Plymouth. After she came to 

 an anchor in Catwater, their attachment appeared to have 

 increased ; they kept constant guard to the vessel, and 

 made themselves so familiar, that one of them was actu- 

 ally captured by a gentleman in a boat alongside, but, by 

 a strong effort, it escaped from his grasp, and regained 

 the water. After this the two fish separated ; but they were 

 both taken the same evening, and, when dressed the next 

 day, were found to be excellent eating. In October 1833 

 nearly one hundred pilot-fish accompanied a vessel from 

 Sicily into Catwater, but they were not taken.'"- The 

 pilot-fish is of a silvery blue colour, paler below, with 



' Annaks du Mus. i'H'ist. Nat. t. ix. p. 4C9. In further illustration of the subject, we sliall subjoin a short extract from a recent 

 publication, Dr Aleyen's Reise urn die Erdc. " The pilot swims constantly in front of the shark ; we ourselves have seen three in. 

 stances in which the shark was led by the pilot. "When the sea-angel neared the ship, the pilot swam close to the snout, or near one 

 of the breast fins of the animal ; sometimes lie darted rapidly forwards or sidewards, as if looking for something, and constantly went 

 back again to the shark. AVhen we threw overboajd 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 round his snout, and splashing, as if to give him exact information as to tlie bacon. The shark now began to 

 put himself in motion, the pilot showing him the way, and in a moment he was fast upon the hook. Once we watched a pilot for many 

 days, who kept constantly swimming close before the'keel of the ship. The sailors say, as of a thing well known and familiar, that such 

 a iish so situated has lost his shark, and is seeking another. Upon a later occasion, we observed two pilots in sedulous attendance on 

 a blue shark, which we caught in the Chinese Sea. It seems probable that tlie pilot feeds on the shark's excrements, keeps his 

 company for that purpose, and directs his operations solely from this selfish view." On this very singular subject we are tempted 

 to quote another anecdote, which, notwithstanding what we have said in the text above, if correctly observed and recorded, would 

 certainly indicate something remarkable in the association of these species. The account was furnished to the editor of the English 

 edition of the Animal Kingdom (vol. x. p. (iSC), by Colonel Hamilton Smith, an accurate and accomplished naturalist. " Captain 

 Richards, R. N., during his last station in tlie Siediterranean, saw on a fine day a blue shark, which followed the ship, attracted 

 perhaps by a corpse which had been committed to the waves. After some time a shark-hook, baited with pork, was flung out. The 

 shark, attended by four pilot-fish. Scomber ductor, repeatedly approached the bait ; and every time that he did so, one of the pilots, 

 preceding him, was distinctlv seen from the tatfrail of the ship to run his snout against the side of the shark's head, to turn it away. 

 After some farther plav, the' fish swam off in the wake of the vessel, his dorsal fin being long distinctly visible above the water. 

 WTien he had gone, however, a considerable distance, he suddenly turned round, darted after the vessel, and before the pilot-fish 

 could overtake him and interpose, snapped at the bait and was taken. In hoisting him up, one of the pilots was observed to cling to 

 his side until he was half above water, when it fell off. All the pilot fishes then swam about awhile, as if in search of their friend, 

 with every apparent mark of anxiety and distress, and afterwards darted suddenly down into the depths of the sea. Colonel H. 

 Smith has himself witnessed, with intense curiosity, au event in all respects precisely similar." 

 ' British Fishes, p. 151. 



VOL. XII. 



2 A 



