1 5 o FISHES OF AUSTRALIA. 



more highly-prized fishes. Young Yellowtail up to a few 

 inches in length simply swarm in the various inlets along 

 the coast of New South Wales, at all seasons of the year. 

 Adults are seldom seen in any quantity, as they keep more 

 to the outside waters. Very young fish, from about three- 

 quarters of an inch in length up to about 2 inches, are very 

 often to be found in summer time in our harbours swim- 

 ming in little shoals beneath (or behind as it often is) the 

 friendly shelter of the "umbrellas" of Medusa of various 

 kinds; particularly the common light-blue "Blubber" that is 

 seen in such immense numbers at times. This is a known 

 habit of the species in other parts of the world and I have 

 personally observed it repeatedly in the upper waters of Port 

 Jackson. 



Being carnivorous and highly voracious, the Yellowtail 

 is not very particular as to its food, provided that it is 

 flesh of some kind; usually, however, it subsists upon fish 

 fry, small crustaceans and mollusks. 



In this species, the scales of the lateral line, are, for the 

 greater part, large and plate-like; a number of them being 

 sharply-keeled, the keel ending in a spine. 



The length of the largest specimens usually seen on the 

 New South Wales coast, is about 12 or 13 inches. 



In New Zealand, where this fish is very common, it is 

 often known under the Maori name of "Hauture." The 

 name of "Scad," also, is often applied to the species in 

 various parts of the English-speaking world. 



When a few Yellowtail are examined, it will usually 

 be found that in the majority of cases, the fishes are acting 

 as a host to one of the parasitic isopod crustaceans. This 

 crustacean (Meinertia imbricata) attains a length of con- 

 siderably over an inch and inhabits the mouth of the Yellow- 

 tail; clinging on to the tongue. It finds its way into the 

 mouth of the fish while it is in a pelagic or free-swimming 

 state during its babyhood. At that time, there is a freely- 

 moving tail portion and the legs show a greater amount of 

 development ; but after "settling down" in the mouth or the 

 pharyngeal cavity of the fish, the tail portion of the crus- 

 tacean becomes dwarfed and stiff, while the legs become 

 modified into sharp hooks which point inwards, facing one 



