Diseases of Fishes 357 



specimens of Sternoptyx diaphana in the Japanese Kuro Shiwo, 

 killed by the earthquakes of 1896, which destroyed fishing 

 villages of the coast of Rikuchu in northern Japan. 



Mortality of Filefish. — Some years ago in the Gulf Stream 

 off Newfoundland an immense mortahty of the filefish (Loplio- 

 latilus chamccleonticeps) was reported by fishermen. This hand- 

 some and large fish, inhabiting deep waters, died by thousands. 

 For this mortality, which almost exterminated the species, no 

 adequate cause has been found. 



As to the destruction of fresh-water fishes by larger ene- 

 mies, we may quote from Professor H. A. Surface. He says 

 there is no doubt that these three species, the lale lamprey 

 {Petromyzon mariuns unicolor), the garpike {Lepidostetis osseus), 

 and the mud-puppy {Necturns maculosus), named "in order 

 of destructiveness, are the three most serious enemies of fishes 

 in the interior of this State [New York], each of which surely 

 destroys more fishes annually than are caught by all the fish- 

 ermen combined. The next important enemies of fishes in 

 order of destructiveness, according to our observations and 

 belief, are spawn-eating fishes, water-snakes, carnivorous or 

 predaceous aquatic insects (especially larvae), and piscivorous 

 fishes and birds." The lamprey attaches itself to larger fishes, 

 rasping away their flesh and sucking their blood, as shown in 

 the accompanying plate. 



