10 NEW SOUTH WALES 
CHAPTER II. 
The Fish Fauna of New South Wales. 
In order to understand the characteristics of the fish fauna of the 
coasts and rivers, it will be necessary to explain something of the fishes 
of the Australian region generally. They do not differ in any singular 
or remarkable degree from the fishes of the rest of the world. If there 
are one or two apparent exceptions to this, it is in the case of some 
Australian fishes which have representatives, not living, but in remote 
periods of the world’s geological history. Such examples are found in 
the Ceratodus, which inhabits the rivers of Queensland, and the 
Cestracion, or Port Jackson shark (Heterodontus). The dentition of the 
last is extremely like fossil teeth of Acrodus, found in mesozoic deposits. 
Ceratodus isan existing ganoid fish, which is abundantly and almost 
exclusively represented in the Trias formation. Its anatomy also shows 
it to be a faint connecting link between a lizard and a fish. 
Except for such rare instances, the families of Australian fishes are 
only slightly different from those of other seas. Some are absent and 
some are very poorly represented, but the great mass of them have 
relations with these of neighbouring seas or those in which the same 
conditions of temperature and coast line prevail. There are however 
minor differences, especially in genera, and these give to Australia 
whatever distinctive characteristics are possessed by its fish fauna. We 
find also that these Australian features are more marked on the southern 
than in the northern coasts. The more remote our coasts are from other 
lands the more peculiar and distinct are the characters which the coast 
fishes present, which is just what we might expect. Thus, on the north, 
north-west, and north-east coasts the fauna is closely connected with 
that of the Indian and tropical seas, and is in very many species identical 
with it. The tribes of the colder regions are here wanting and in place 
we have the fishes of the equatorial zone in all their gorgeous liveries 
of red, blue, green, and gold, arrayed in those fanciful patterns which 
awaken the enthusiasm of every naturalist. We find also that as we 
go southwards on either coast there is a gradual disappearance of the 
tropical fauna and a mingling of that of the temperate regions. Now 
if we cast our eyes on the limits of the coasts of New South Wales, we 
shall find that they lie in regions where the fishes are most likely to be 
intermediate in character. No part of the Colony is within the tropics, 
though its northern boundary is not five degrees from the tropic of 
Capricorn, Again, no part of the Colony abuts upon ‘the south coast, 
but its southern limits are just at the entrance of Bass’s Straits. Thus 
it is cut off from the equatorial, and again from the South Australian 
regions. In such a province we can only expect that what is peculiar 
in its fish fauna will belong to the Pacific Ocean, and in fact it does 
possess more of the fishes of that area than any other portion of the 
coasts of Australia. It may be necessary further to mention that these 
remarks apply to the shore fishes only, that is, fishes which inhabit 
shallow waters in the neighbourhood of land. Pelagic fishes are those 
which inhabit the surface or uppermost strata of the open sea and only 
visit the coasts accidentally in search of prey or periodically for the 
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