POSTLARVAL STAGES OF AUSTRALIAN FISHES. 
141 
the progressive development of this pattern are shown in text tigs. 2B and 2C. 
There is a rapid early change in the head pigment. The chromatop'hores over- 
lying the brain greatly increase in size and number and form intensely dark 
rounded patches, one on either side of the head behind the eyes. These are 
more obvious than in A. australis. The spinous dorsal tin membrane receives 
some black pigment when a size of about 18-0 millimetres is attained but is 
not so intense as in the Bream. Also at this stage of development scales are 
apparent. The lateral line is discernible at 20-0 millimetres. During the 
subsequent ten millimetres growth the rows of scales become visible macro- 
scopically, outlined as longitudinal parallel bands of a brownish colour. These 
develop into the characteristic longitudinal golden bands of adults, there being 
six or seven above the lateral line and considerably more below it. Postlarval 
Tar whine less than 18-0 millimetres in length have been collected at Caloundra 
as early as June and in the Noosa River as late as October. 
Text tig. 2 indicates how the body proportions alter greatly early in 
postlarval life. At a size of 18-0 millimetres the body height has exceeded the 
head length, which has increased to 3| in the total length. The eye remains 
conspicuously large. At a length of 30-0 millimetres the steepness of the snout 
is most noticeable when the head is viewed in profile. 
A comprehensive series of stages constituting a complete range of 
intermediate sizes from planktonic postlarvae to adults form the basis of this 
description. 
3. PELATES SEXLINEATUS (Quoy & Gaimard). TRUMPETER PERCH, 
Pristipoma sexlineatus Quoy & Gaimard (1824), p. 320. 
Pelates quadrilineatus Cuvier & Valenciennes (1829), p. 146, pi. lv. 
A third type of planktonic postlarva with facies generally resembling 
those of postlarval A. australis and A. sarba has been collected in tow nets, both 
in the Noosa River and Bribie Passage estuaries. Two specimens (84 mm.) 
were obtained in March 1944 near the Bribie Passage (Caloundra) entrance 
and a further four specimens (5*5, 10-5, 11-0 mm.) in the Noosa River during 
the following month. Others (12-9 to 13-6 mm.) were obtained in the same 
locality during June 1940. Another (13-5 mm.) was collected in the Noosa 
River plankton as late as October in 1944 and on the previous day (13/10/44) 
three other individuals (11-2 to 12-6 mm.) were caught in a dip net at Tewantin 
township, several miles upstream. The latter were amongst a school of small 
postlarval Ambassis jacks oniensis which were working in close to the bank. 
These postlarvae have been identified as those of the common little 
Trumpeter Perch, Pelates sexlineatus (Q. & G.) which is invariably present 
during most months of the year amongst weed growing in the shallows of most 
east coast estuaries. The October planktonic postlarvae illustrated in 
text fig. 3B (13-5 mm.), by virtue of its possession of an intermediate pigment 
pattern, links up between the younger planktonic postlarva (text fig. 3A) and 
the tiny recognisable juveniles of this species that frequent the Zostera beds 
in sheltered places. The fin formula D. Nil, 10 ; A. Ill, 10 ; P. 15, characteristic 
of this species and possessed by these planktonic post-larvae gives the necessary 
confirmation to the diagnosis. 
