POSTLARVAL STAGES OF AUSTRALIAN 
FISHES.— NO. l. (4) 
By Ian S. R. Munro, M.Sc. 
(Council for Scientific and Industrial Research). 
(Text-figures 1-8.) 
It has been the good fortune of the writer to obtain, whilst netting in 
the estuaries of southern Queensland and New South Wales, many interesting 
larval and postlarval stages of fishes. In most instances these very young stages 
differ considerably from the adults of the same species both in proportions and 
coloration. They present more than the usual difficulties in their specific identi- 
fication. Descriptions of juvenile stages of even the commoner Australian fishes 
have never featured to any extent in ichthyological publications. It is the 
object of this series of articles to outline the principal characteristics of hitherto 
undescribed early developmental stages of many of our commercial and better 
known species. 
As most of the postlarvae featuring in the following descriptions are less 
than twenty millimetres in length, special gear had to be employed for collecting. 
Plankton tow nets were useful for the capture of the smaller pelagic larvae 
and postlarvae. The bulk of the collecting was carried out by means of a 
special small meshed hauling seine net designed by the writer for the specific 
task of capturing fish fry sheltering in Zostera weed beds of shallow creeks 
and mud flats, and in the sandy shallows near river mouths. This net was shot 
by wading it around at low tide. Its length was 25 yards and the depth four 
feet. The bunt was of 7 millimetre square meshed French netting with an 
innermost section and pocket of 4 millimetre square mesh. The wing sections, 
each of 10 yards, were of J inch prawn netting. This type of net was found 
to be most successful for this particular purpose. 
Acknowledgment is due to Mr. G. L. Kesteven, who made available a 
quantity of unsorted plankton from the Noosa River collected in June 1940. 
This is supplementary to the writer’s own extensive monthly plankton collections 
during the years 1944 and 1945. 
1. ACANTHOPAGRUS AUSTRALIS (Gunther). AUSTRALIAN BREAM. 
Clirysophrys australis Gunther (1859), p. 494. 
A detailed description of the eggs and early larvae of the Australian 
Bream has already been published by Tosh (1903). Kesteven and Serventy 
(1941) have shown that this species spawns near the mouths of southern 
Queensland rivers. It may be added that the main spawning begins with the 
Sea Bream runs of May and June but sometimes occurs earlier and appears to 
continue throughout the winter months. The eggs are pelagic and are spawned 
at night on a flooding tide when the moon is full. The larvae are planktonic 
4 Contribution No. 41 from the Marine Biological Laboratory, C.S.I.R., Division of 
Fisheries, Cronulla, New South Wales. 
