THE SUCKING-FISHES. 189 



CHAPTER X. 



The Sucking- Fishes Scorpaenoid Fishes The Flatheads Gurnard 

 or Gurnets Flying Gurnards or Sea Robins Leptoscopoid Fishes 

 Notothenioid Fishes The Star Gazers Trichonotoid Fishes. 



THE SUCKING-FISHES. 



(Family: Echeneididce.) 



AMONGST fishes which are remarkable for peculiarity of 

 habit and structure, the Sucking-Fishes certainly stand in 

 the front rank. These curious creatures are provided with 

 a long, oval, transversely-laminated, suctorial disk on the 

 top of the head and by its aid, they are able to attach them- 

 selves to the bodies of Sharks and other large fishes or ceta- 

 ceans. They are also known to attach themselves to the 

 bottoms and sides of ships. Thus they are enabled to travel 

 over vast areas with a minimum of muscular effort. Sharks 

 are the principal "hosts" (if I may use the term) of the 

 Sucking-Fishes, and hardly a large one is caught that has 

 not 2 or 3 of the latter as attendants. Very often they 

 remain attached when a Shark is hauled out of the water; 

 great force being required to dislodge them, owing to the 

 wonderful way in which they adhere. The sucking-disk by 

 which this adhesion is brought about, is a very remarkable 

 organ. It possesses a long central longitudinal division and 

 numerous short transverse ones : The number of these trans- 

 verse divisions, varies considerably in the different species, 

 though the general plan of arrangement is always the same. 

 The sucking or "cupping" action is produced in the same 

 way as that of the suckers on the tentacles of the Octopus ; 

 that is, by the formation of a partial vacuum; in this case 

 caused by raising the partitions dividing the various com- 

 partments of the disk. To give an idea of the great utility 

 of this organ, I may mention that I have taken one of these 

 Sucking-Fishes, even several hours after death, and applied 

 the sucking-disk to a piece of smooth glass giving a slight 



