March 1948 The Queensland Naturalist 
89 
Various other types of fish may be seen in the Somer- 
set Dam region, the most common perhaps being the 
freshwater catfish — Tandanux fund anus — often referred 
to in Queensland as the new-fish (or Dew-fish or Dhu- 
fish). The term Jew-fish would perhaps be better kept 
fit refer to the marine fish (Sriantit antiirfira) , com- 
monly called such in other parts of Australia. The Perch 
or Spotted Grunter — Therupon unicolor — is also quite 
abundant. At certain times of the year the dissipator 
lias been < bserved to contain a seething mass of eels - 
Any u ilia it list ml is. The Lungfish — ■Neoeeratodus forsteri— 
h:s also been observed at night-time, but not very 
frequently. 
Among the smaller fish observed from the area, most 
outstanding perhaps are the Jewel-fish — Melanotaeniu 
niyums — a very pretty little fish of length about 5-8 
cins, with bright reddish laterally-situated spots, and 
the Black-tipped Perehlet — Priopis nigripennis — which 
is quite typically marked. 
On occasions the fish generally, and in particular 
the Bony Bream, have been recorded dead in great quan- 
tities in the dam — a phenomenon not uncommon in many 
parts of Queensland, occurring in dams and freshwater 
pools, etc. From previous records and present observa- 
tions, it would seem that this occurrence takes place 
mainly dming t lie years when dry conditions and drought 
prevail. 
Examination of some of the dead fish indicates that 
the problem is not one of general fish-food shortage, and 
most of the commonly postulated theories, on investiga- 
tion, prove finally to be untenable. This problem is one 
that has remained unsolved over a great many years, and 
B perhaps the outcome of a great many inter-dependent 
factors which serve to complicate investigational work. 
It is suggested by the author that perhaps the key 
to the whole problem lies in the variation of the oxygen 
content of the water. A theory postulated is that 
the fish being well fed. with decreased oxygen available, 
become increasingly sluggish, and as a result the fat. 
commonly found in the body of the affected fish, is 
deposited. With the continuation of drought conditions, 
the oxygen content of the water continues to decrease, 
