120 
SPOLIA ZEYLANIOA. 
others like them. In other places it is recognized that methods of 
culture should be based upon a knowledge of the breeding habits of 
fishes under natural conditions,* and if this point of view is accepted 
locally the utility of these notes on ‘ ‘ lula 55 may be taken for granted. 
The necessity of differentiating between the successive ages and 
stages of the growing fish, and between fry of the same age belonging 
to species which may be closely allied zoologically though far apart 
economically, and the study of the conditions under which fry can 
be reared best under an artificial system, are points which must 
always guide cultural operations whenever they are undertaken. 
The feeding of ‘‘lula ” during its earlier stages is not an insuperable 
difficulty, and under suitable conditions it even goes forward to a 
large extent automatically. It is known that the growth of fishes is 
governed directly by the food-supply. ‘ ‘ Lula ” is one of those fishes 
whose size-limit is practically indefinite. The more food it receives 
of the right kind, the quicker and the larger it grows. Some young 
‘ ‘ lula ’’which I kept in an aquarium at my bungalow in Colombo had 
an average total length of about 35mm. in February, 1908 ; 45 mm. 
in July, 1908; 96 mm. in April, 1909. The series last measured con¬ 
sisted of six individuals ranging from 85 mm. to 115 mm. The latter 
measurement may be taken as representing approximately the usual 
growth of a yearling “ lula,” although under more favourable condi¬ 
tions it might reach six inches in total length from the tip of the snout 
to the end of the tail fin. It will be observed that in the nine months 
from July to April the young 4 ‘ lula ” more than doubled their length. 
A sample of “ kavaiya ” fry, Anabas scandens, six in number, kept in 
the same tank at the same time, behaved in a similar manner ; when 
first measured in June, 1908, their average length was 33 4 5 mm.; a 
month later the average had increased to 41 mm.; and in April, 1909, 
it had reached 83 mm. Another tropical freshwater food-fish, which 
may be introduced into Ceylon some day, namely, the Gourami 
(Osphromenus olfax) , is known to attain a length of about four inches 
in the first year, seven or eight in the second, and ten or eleven in 
the third, after which it begins to breed.f 
From what has been said above, and also from what has long been 
known respecting the powers of endurance possessed by the Ophioce- 
phalidae, it is obvious that, as soon as required, yearling “lulu” 
could be reared with comparative ease in protected ponds, and 
could be distributed subsequently as required. 
The extent to which the fry of freshwater fishes depend for their 
sustenance upon the aquatic larvae of mosquitoes or Culicidae is a 
matter of practical moment and also of special interest at the present 
* Compare Dwight Lydell. The habits and culture of the Black Bass. U. 
S. Fish Comm. Bull., 1902 (Washington, 1903), pp. 39-44, PI. 8. 
f See A. Willey. Ceylon Admin. Rep.. 1908. Marine Biology (including 
first part of Report on Inland Fisheries). 
