182 ON THE COMMON WHITING OF MORETON BAY 



dark blotches — with no evident arrangement — on the upper side 

 of the body. At one year (PI. XII., fig. 1) they begin to assume 

 the oblique arrangement described for .S\ maculatu ; at two years 

 they have run into one another to form about eight oblique 

 irregular bands running downwards and forward. By that time 

 they are very indistinct, and can be shown or not according to 

 environment. In no case do the markings show below the 

 lateral silvery band or on the tail (cf. S'. mncnlata, Bleeker, 

 At. Ich. Ind., T. 8, Tab. 889, Fig. 5). Well-grown fish when 

 just taken from the water show sometimes from 6 to 8 dark areas, 

 extending about -fin. out from the median dorsal line. They 

 disappear when some time out of the water. The dark colour 

 is not even in the blotchings which have rather a mottled 

 appearance. 



The markings on the young whiting, when seen from above 

 in its natural surroundings, counterfeit very accurately the 

 shadows of the ripples on the sand surface below. 



Rate of Growth. 



Observiitions on the whiting were in progress from June to 

 January. Early in June young whiting of last season's spawn- 

 ing can be taken at lengths varying from 31 to 79 mms. Aver- 

 ages of sizes divided arbitrarily into two groups — those over 

 50 mms. and those under — give approximately the lengths 

 attained at that time b} those spawned early and those late in 

 the season. At 10th June averaging 40 of each group, the early 

 spawned fish were 68 mms. and the later ones lO mms. On 

 24th June the average of all sizes was 70, and on 19th August 

 72 mms. On 7th October, at the beginning of the spawning 

 season, the average was 76 mms., or about three inches. At the 

 same time the average size of a number of two-year old whiting 

 was found to be 201 mms., or about eight inches. That was of 

 course early in the spawning season, and the sizes of one and 

 two-year old lish probably exceed slightly those given. These 

 two-year olds had reproductive organs of small size, but well 

 advanced. They spawn in the early months of the year. It is 

 very probable that fish spawned late in the season do not breed 

 till the third year. 



