SKIMMING THE SURFACE 



''In attacking the mackerel," says Verrill, ''they sud- 

 denly dart backward among the fish with the velocity of 

 an arrow." The name "sea-arrow" may therefore have a 

 dual origin — it may have been bestowed on the flying 

 squid by fishermen who have known of its method of 

 attacking mackerel or other fish, apart from the use of the 

 name by mariners who have seen "sea-arrows" fall on to 

 the decks of their ships. 



The flying squid shows uncanny skill in attacking 

 mackerel and other fish. Once among them it will sud- 

 denly turn obliquely to the left or right, seize a fish, and 

 instantly kill it by biting it in the back of the neck with 

 its sharp beak. This is an amazingly efficient operation, 

 and is performed with such rapidity that it reminds us of 

 the practice of the spider, which cuts a nerve of its victim 

 so quickly and skilfully that it is not killed but para- 

 lysed : the spider needing the helpless victim alive and 

 with its blood circulating, for its larder. 



Tarpon are acrobatic fish which grow to a length of 

 seven feet or more, and may weigh anything up to 

 350 pounds. Any over a mere twenty-five or thirty pounds 

 can tow a spearman and his boat with ease. 



The fish has a peculiar modification of its dorsal fin : 

 the last ray is drawn out in a whip-like filament, which 

 seems to aid the tarpon in its sensational leaps. Before 

 jumping, the fish whips this filament to the side of its 

 body and clamps it there : an action which has the effect 

 of holding the dorsal fin rigidly at an angle. This angle, 

 remarkably enough, is prearranged by the fish in accord- 

 ance with the course of its leap — to left or right as the 

 case might be. A few authorities doubt the truth of this 

 prearranged fixation of the dorsal fin, but all seem to 

 agree that the "whip" is used in some way in relation to 

 the leap, and if it is not used to hold the fin rigid there 

 seems to be no purpose in it as an appendage, while the 

 creature's movement before leaping remains mysterious. 



Tarpon are provided with very large gills by means of 



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