1915] The Ottawa Naturalist. ill 



THE CURIOUS EGG OF THE HAGFISH (MYXINE). 



By Professor* Edward E. Prince, Dominion Commissioner 



OF Fisheries, Ottawa. 



In classifying fishes, scientific authorities have always plac- 

 ed lowest on the list the hagfishes and lampreys. Indeed, 

 the well-known writer on fishes, William Swainson, in his ex- 

 cellent book, the "Classification of Fishes," London, 1838, goes 

 so far as to claim, regarding the hagfish (Myxine), that "all 

 authors agree in placing it near the worms." These fish are, of 

 course, far removed from the worms; but with the exception 

 of the Lancelet (Branchiostoma or Amphioxus), they are the 

 lowest and most rudimentary of vertebrate animals. The late 

 Dr. Theodore Gill and others concluded that they ought to 

 be separated from the true fishes, and placed in a separate class, 

 owing to their many rudimentary structural features. Thus, 

 they have no paired fins, no scales, no segmented backbone, 

 (the jelly-like notochord persists), no complete skull, no spleen, 

 no pancreas, a very simple brain and nervous system, a peculiar 

 series of gill-pockets instead of typical filamentous gills, and 

 their whole form and structure are in contrast with the true 

 fishes, and higher vertebrates generally. It is still a debated 

 question whether or not, in this peculiar group, the features 

 referred to are original and primitive or degraded and dege- 

 nerate. In all, the mouth is rotmd and adapted for sucking, 

 not biting. The lamprey attacks fishes, adhering to the out- 

 side with its mouth, w^hich it uses like a vacuum sucker, and 

 removes flesh and blood with its rasp-like horny teeth. The 

 hagfish bores its way into fishes, living or dead, and eats out 

 the interior, leaving little more than the skin and bones of its 

 victim. Fishermen find cod and haddock hanging to their hooks 

 which have been destroyed in this way. Moreover, the hagfish 

 has a remarkable device for protecting itself from enemies. The 

 skin is provided with slime glands and pores, which enable it, 

 at will, to pour out a great quantity of tenacious ropy slime, 

 in which it envelops itself. I have seen a specimen, the size 

 of a medium-size eel, fill a bucket with this gummy grey sub- 

 stance, exuded from the slime pores. There are not many 

 species of hagfishes, and they are very local in their occurrence. 

 Thus, Myxine gluiinosa is well known to abound off St. Abb's 

 Head on the Scottish coast, but is rather rare in other areas. 

 Our Canadian hagfish so closely resembles the British form that 

 both were included in the same species, though our western 

 form is now known as Myxv^ie liniosa. 



