PERCH-LIKE FISHES 167 



Experts are frankly sceptical of many of these " yarns ". 

 They are loath to admit the possibility of such an aggressive 

 partnership between creatures so diverse as the Sword-fish and 

 the Thresher Shark, and they find it difficult to understand 

 why the former should make an unprovoked attack upon one 

 of the larger whales. Many hold the view that the attackers 

 were not Sword-fishes or Threshers at all, but Killer Whales, 

 and this seems a likely explanation. In this connection we 

 may note that the Killer Whale itself is sometimes known by 

 the popular name of " Swordfish ", probably on account of 

 the shape of its dorsal fin (see p. 290). Others, while inclined 

 to reject many of the stories of alleged attacks, do credit the 

 Sword-fish with the habit of " going berserk " on occasions, 

 and of venting its spleen on the nearest object, whether it be 

 a whale, ship or rock ! It is certainly true that a number of 

 authentic records of attacks upon small fishing vessels do 

 exist. 



Some of the older books contain stories of attacks upon 

 man himself, and in Daniel's ' Rural Sports ' we read that in 

 the Severn, near Worcester, a man was " struck, and absolutely 

 received his death wound through a swordfish ". 



The breeding habits of the Sword-fish are as yet somewhat 

 imperfectly known, but it has been conjectured that they 

 pair during the spawning time, which, at least in the Mediter- 

 ranean, takes place in late spring or early summer. The eggs 

 are small and buoyant, and the larval fish hatches out after 

 about z\ days. The newly-hatched larva shows no trace of 

 the rostrum. A little later the young Sword-fishes are still 

 curious looking creatures, and so unlike their parents that they 

 were originally mistaken for an entirely different species. 

 They have both the jaws nearly equal in length, and armed 

 with long, pointed teeth, but as they grow up the lower jaw 

 becomes gradually shorter and the teeth disappear. There is 

 a single high dorsal fin along the whole length of the back, and 

 along either side of the slender body are four rows of spiny 

 plates. The caudal fin is at first scarcely forked, and the 

 fleshy keel on the peduncle is wanting. An interesting feature 

 of the young fish is its resemblance to a fossil Sword-fish 

 (Blochius) found in the Eocene formations of Monte Bolca in 

 Italy. 



