are enclosed in thin membranesc In general they do not form 

 layers,, but in the white marlin they do make up 2 - 3 layers 

 and the membranes surrounding these are tough. A point to be 

 noted is that these bubble-like air chambers appear even beyond 

 the body cavity in the caudal region. That iSj there are many 

 small air chambers arranged in rows between the muscles at the 

 origins of the first and second anal finso This sort of struc- 

 ture is completely lacking in the Scombriformes and the broadbill 

 swordfishj and it is a conspicuous characteristic of the 

 istiophoridso 



The viscera of the Xiphiidae are similar to those of the 

 Istiophoridae^ but they differ in such points as having a 

 longer intestine with many small corrugations on its surface 

 and of uneven diameterp having the total mass of the pyloric 

 caeca remarkably small j, having tne air bladder single-chambered j 

 and in having no air chambers beyond the body cavity in the 

 caudal regiono 



Co Ecology 



io Outline of habits 



The spearfishes are large fishes which migrate widely in 

 the open seao Basically they are animals of the tropical seas^ 

 but in certain seasons they also appear in the waters of higher 

 latitudeso They generally occur in the shallow layers and 

 sometimes swim with a portion of the caudal and dorsal fins 

 showing above the surface of the watero They are also known 

 occasionally to leap into the air,, The broadbill is fierce and 

 is said to attack whales upon occasion,, At such times it is 

 thought to use its sword-shaped snout as a weapono Such char- 

 acteristics are not known in the case of the fishes of the 

 family Istiophoridaej but it is generally believed that these 

 fishes use their beaks as weapons in fighting and in attacking 

 the animals upon when they f eedo ThiSg however^ is probably 

 something which has been imagined by people after seeing the 

 form of the fish for it is thought that in actuality they do 

 not use their beaks to catch their prey,. The reason for this 

 is that when the stomach contents of these fishes are examined^ 

 they bear the scars of bites 5 but wounds inflicted by stabbing 

 have not yet been foundo The fishes of the family Istiophoridae 

 have file-like teeth on both jaws^ but if the objectives were 

 to catch their food by stabbing it should be most advantageous 

 to have their weapon as sharp as possible. It cannot be believed 

 that there would be any need for teeth which would increase the 

 resistance,, Even though the beak may be used as a weapon 

 against large enemies ^ it cannot in the least be thought that 

 it is used to capture foodo It is also said that they occasion- 

 ally attack fishing boats ^ but there is a great deal of doubt 

 as to whether these fish make such attacks deliberately^, Nor 

 is the rostrum essential to the existence of these fishes for 



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