8 MALAYAN FISHES. 
Their density causes them to sink lower in brackish water until 
they eventually find bottom in the shallow bays and estuaries and in 
this way are gradually dispersed all long the coast. Then a 
metamorphosis takes place and the feeble Leptocephalus is trans- 
formed into the active little fish which swims vigorously against 
the current and feeds incessantly and voraciously all the time. 
In a recent report on the Fisheries of the Straits Settlements 
and Federated Malay States the writer drew attention to the 
Chinese fish-traps called pompang and other licensed fixed engines 
known as ambai, langgat, etc., of which there are several thousand 
between Penang and Port Swettenham. Though there are many 
kinds of these traps they all work on the same principle. In every 
case there is a wide V-shaped entrance terminating in a long 
funnel-shaped bag made of sacking or plaited split bamboos. The 
position of these traps is arranged with respect to the currents 
and tides so as to intercept the larvae and immature fish during 
their denatant drift to the shallows. Most of these traps float, and 
swing round with each tide so as to take toll both with the ebb and 
the flow, 
An examination of the contents of these traps shews that in 
addition to immature fish, which any Malay fisherman will tell you 
are the fry of valuable food fish, the bulk of the catches are made 
up of feeble, attenuated, small-headed larval-lhke fishes which the 
Malays call Bunga ayer and to which they attach no value. 
There can be little doubt that scientific investigation will prove 
that the Bunga ayer are valuable food-fish in the Leptocephalus 
stage, 
This subject has been treated at some length because of its 
great economic importance and because the questions raised cannot 
be answered except by a specialist in marine biology. 
Though myriads of larval and immature fish are caught daily 
for duck food, pig food and manure, and thousands of pikuls are 
exported as dried fish refuse, it has been argued, while admitting 
ambar catches are used mainly as pig food, that it appears a 
debatable point whether the flesh value thus produced is not as 
great as the extra fish value which might be caught if the fry killed 
by ambai were left undisturbed! 
We cannot afford to allow such points to remain debatable. 
Let us go on with the life history of the tiny fish which we 
left in the first stage of an active existence in the shallow waters 
near the coast. These shallows are the nurseries or recruiting 
grounds where the fry keep together in schools or shoals. 
“After a period in relatively shallow water, the shoal 
migrates to deeper water. At first the migration is not to a 
great distance, but with growth the annual pulsation becomes 
greater and greater, 
