138 GIANT FISHES 



CUTLASS-FISHES OR HAIR-TAILS. 



(Family Trichiurid^e.) 



Trichiuroids with a very long, band-shaped body, and with 

 a completely scaleless skin. Sometimes the spinous part of 

 the dorsal fin is not distinct from the soft part, but if they are 

 separated the spinous portion is never the longer. The anal 

 fin has numerous short spines. The caudal fin is either small 

 or is wanting altogether. The pelvic fins are either reduced 

 to a pair of scale-like appendages or are absent An air- 

 bladder is present. 



These are surface fishes found in all warm seas, some 

 inhabiting coastal waters, others the open sea. 



SCABBARD-FISH. 



(Genus Lepidopus.) Fig. 46. 



There is a row of minute teeth on each side of the roof of 

 the mouth. A single dorsal fin extends along the whole of the 

 back, supported by about 100 rays. The anal spines are 

 numerous, but they are very small or hidden beneath the skin. 

 The caudal fin is present, and is forked. The pelvic fins are 

 represented by a pair of scale-like appendages, and are placed 

 behind the pectorals. The coloration of the head and body is 

 uniformly silvery, the fins being pale grey, dashed with yellow. 



Grows to a length of 6 feet. 



There is probably only one species (L. caudatus), widely 

 distributed in all the warmer seas. It is a very occasional 

 visitor to the British Isles during the summer months. 



This is a surface fish, remarkable for the speed with which 

 it is able to swim. Practically nothing is known of its manner 

 of life, but its food appears to consist mainly of other'fishes. 

 Accustomed to living in tropical and temperate seas, it is 

 very sensitive to cold, and in New Zealand it sometimes swims 

 ashore in its thousands on frosty nights, apparently in a state 

 of temporary insanity. This habit has earned for it the local 

 name of " Hiku " or " Frost-fish ". 



